@article{Raskar:2001:HSN, author = {Ramesh Raskar }, title = {Hardware Support for Non-photorealistic Rendering }, journal = {2001 SIGGRAPH / Eurographics Workshop on Graphics Hardware}, year = {2001}, month = {August}, editor = { }, publisher = {ACM Press}, pages = { }, note = { }, annote = { }, } @article{Freudenberg:2001:WIF, author = {Bert Freudenberg and Maic Masuch and Thomas Strothotte}, title = {Walk-Through Illustrations: Frame-Coherent Pen-and-Ink Style in a Game Engine}, volume = {20}, number = {3}, journal = {Computer Graphics Forum}, year = {2001}, publisher = {Blackwell Publishers}, note = {ISSN 1067-7055}, annote = { In this paper we show how a game engine designed to generate photorealistic images can be extended to produce non-photorealistic and hybrid renditions. We introduce new hardware-based methods to accomplish pen-and-ink illustrations. The combination of the highly optimized processing of a game engine and the use of hardware for NPR algorithms yields real-time animation of pen-and-ink illustrations. The particular advance of this method is that it yields the first real-time, frame-coherent pen-and-ink animations which maintain both tone and texture. }, } @article{Bourguignon:2001:DFI, author = {David Bourguignon and Marie-Paule Cani and George Drettakis}, title = {Drawing for Illustration and Annotation in 3D}, volume = {20}, number = {3}, journal = {Computer Graphics Forum}, year = {2001}, publisher = {Blackwell Publishers}, note = {ISSN 1067-7055}, keywords = {drawing, stroke-based illustration, interface}, annote = { We present a system for sketching in 3D, which strives to preserve the degree of expression, imagination, and simplicity of use achieved by 2D drawing. Our system directly uses user-drawn strokes to infer the sketches representing the same scene from different viewpoints, rather than attempting to reconstruct a 3D model. This is achieved by interpreting strokes as indications of a local surface silhouette or contour. Strokes thus deform and disappear progressively as we move away from the original viewpoint. They may be occluded by objects indicated by other strokes, or, in contrast, be drawn above such objects. The user draws on a plane which can be positioned explicitly or relative to other objects or strokes in the sketch. Our system is interactive, since we use fast algorithms and graphics hardware for rendering. We present applications to education, design, architecture and fashion, where 3D sketches can be used alone or as an annotation of an existing 3D model. }, } @article{Kang:2001:TIT, author = {Hyung Woo Kang and Soon Hyoung Pyo and Ken-ichi Anjyo and Sung Yong Shin}, title = {Tour Into the Picture using a Vanishing Line and its Extension to Panoramic Images}, volume = {20}, number = {3}, journal = {Computer Graphics Forum}, year = {2001}, publisher = {Blackwell Publishers}, note = {ISSN 1067-7055}, keywords = {Image-based modeling/rendering, projective geometry, vanishing line, panoramic image}, annote = { Tour into the picture (TIP) proposed by Horry et al.is a method for generating a sequence of walk-through images from a single reference picture (or image). By navigating a 3D scene model constructed from the picture, TIP produces convincing 3D effects. Assuming that the picture has one vanishing point, they proposed the scene modeling scheme called spidery mesh. However, this scheme has to go through major modification when the picture contains multiple vanishing points or does not have any well-defined vanishing point. Moreover, the spidery mesh is hard to generalize for other types of images such as panoramic images. In this paper, we propose a new scheme for TIP which is based on a single vanishing line instead of a vanishing point. Based on projective geometry, our scheme is simple and yet general enough to address the problems faced with the previous method. We also show that our scheme can be naturally extended to a panoramic image. }, } @article{Way:2001:TSO, author = {Der-Lor Way and Zen-Chung Shih}, title = {The Synthesis of Rock Textures in Chinese Landscape Painting}, volume = {20}, number = {3}, journal = {Computer Graphics Forum}, year = {2001}, publisher = {Blackwell Publishers}, note = {ISSN 1067-7055}, annote = {In Chinese landscape painting, rock textures portray the orientation of mountains and contribute to the atmosphere. Many landscape-painting skills are required according to the type of rock. Landscape painting is the major theme of Chinese painting. Over the centuries, masters of Chinese landscape painting developed various texture strokes. Hemp-fiber and axe-cut are two major types of texture strokes. A slightly sinuous and seemingly broken line, the hemp-fiber stroke is used for describing the gentle slopes of rock formations whereas the axe-cut stroke best depicts hard, rocky surfaces. This paper presents a novel method of synthesizing rock textures in Chinese landscape painting, useful not only to artists who want to paint interactively, but also in automated rendering of natural scenes. The method proposed underwrites the complete painting process after users have specified only the contour and parameters. }, } @article{Durand:2001:DSH, author = {Fredo Durand and Victor Ostromoukhov and Mathieu Miller and Francois Duranleau and Julie Dorsey}, title = { Decoupling Strokes and High-Level Attributes for Interactive Traditional Drawing}, journal = {Eurographics Workshop on Rendering}, year = {2001}, publisher = {Springer-Verlag}, pages = {}, note = {}, annote = {}, } @article{Gooch:2001:ACI, author = {Bruce Gooch and Eric Reinhard and Chris Moulding and Peter Shirley }, title = { Artistic Composition for Image Creation }, journal = {Eurographics Workshop on Rendering}, year = {2001}, publisher = {Springer-Verlag}, pages = {}, note = {}, annote = {}, } @article{Visvalingam:2001:TCE, author = {M Visvalingam and K Dowson}, title = {Towards Cognitive Evaluation of Computer-drawn Sketches}, volume = {17}, number = {4}, journal = {The Visual Computer}, year = {2001}, month = {}, pages = {}, keywords = {}, annote = { }, } @article{Cornish:2001:VPF, author = {Derek Cornish and Andrea Rowan and David Luebke}, title = {View-Dependent Particles for Interactive Non-Photorealistic Rendering}, journal = {Graphics Interface 2001}, year = {2001}, month = {June}, editor = {Benjamin Watson and John W. Buchanan}, pages = {151--158}, note = {ISBN 0-96888-080-0}, annote = {We present a novel framework for non-photorealistic rendering (NPR) based on view-dependent geometric simplification techniques. Following a common thread in NPR research, we represent the model as a system of particles, which will be rendered as strokes in the final image and which may optionally overlay a polygonal surface. Our primary contribution is the use of a hierarchical view-dependent clustering algorithm to regulate the number and placement of these particles. This algorithm unifies several tasks common in artistic rendering, such as placing strokes, regulating the screen-space density of strokes, and ensuring inter-frame coherence in animated or interactive rendering. View-dependent callback functions determine which particles are rendered and how to render the associated strokes. The resulting framework is interactive and extremely flexible, letting users easily produce and experiment with many different art-based rendering styles. }, } @article{Sloan:2001:TLS, author = {Peter-Pike Sloan and William Martin and Amy Gooch and Bruce Gooch}, title = {The Lit Sphere: A Model for Capturing NPR Shading from Art}, journal = {Graphics Interface 2001}, year = {2001}, month = {June}, editor = {Benjamin Watson and John W. Buchanan}, pages = {143--150}, note = {ISBN 0-96888-080-0}, annote = {While traditional graphics techniques provide for the realistic display of three-dimensional objects, these methods often lack the flexibility to emulate expressive effects found in the works of artists such as Michelangelo and Cezanne. We introduce a technique for capturing custom artistic shading models from sampled art work. Our goal is to allow users to easily generate shading models which give the impression of light, depth, and material properties as accomplished by artists. Our system provides real-time feedback to immediately illustrate aesthetic choices in shading model design, and to assist the user in the exploration of novel viewpoints. We describe rendering algorithms which are easily incorporated into existing shaders, making non-photorealistic rendering of materials such as skin, metal, or even painted objects fast and simple. The flexibility of these methods for generating shading models enables users to portray a large range of materials as well as to capture the look and feel of a work of art. (Color images can be found at http://www.cs.utah.edu/npr/papers/LitSphere_HTML.) }, } @article{Agrawala:2001:RER, author = {Maneesh Agrawala and Chris Stolte}, title = {Rendering Effective Route Maps: Improving Usability Through Generalization}, journal = {Proceedings of SIGGRAPH 2001}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {2001}, month = {August}, editor = {Eugene Fiume}, publisher = {ACM Press / ACM SIGGRAPH}, pages = {241--250}, note = {ISBN 1-58113-292-1}, keywords = {Information Visualization, Non-Realistic Rendering, WWW Applications, Human Factors}, annote = {Route maps, which depict a path from one location to another, have emerged as one of the most popular applications on the Web. Current computer-generated route maps, however, are often very difficult to use. In this paper we present a set of cartographic generalization techniques specifically designed to improve the usability of route maps. Our generalization techniques are based both on cognitive psychology research studying how route maps are used and on an analysis of the generalizations commonly found in handdrawn route maps. We describe algorithmic implementations of these generalization techniques within LineDrive, a real-time system for automatically designing and rendering route maps. Feedback from over 2200 users indicates that almost all believe LineDrive maps are preferable to using standard computer-generated route maps alone. }, } @article{Agrawala:1995:3PO, author = {Maneesh Agrawala and Andrew C. Beers and Marc Levoy}, title = {3D Painting on Scanned Surfaces }, journal = {1995 Symposium on Interactive 3D Graphics}, year = {1995}, month = {April}, editor = {Pat Hanrahan and Jim Winget}, publisher = {ACM SIGGRAPH}, pages = {145--150}, note = {ISBN 0-89791-736-7}, } #2: @article{Agrawala:2000:AMR, author = {Maneesh Agrawala and Denis Zorin and Tamara Munzner }, title = {Artistic Multiprojection Rendering}, journal = {Rendering Techniques 2000: 11th Eurographics Workshop on Rendering}, year = {2000}, month = {June}, editor = {Bernard P{\'{e}}roche and Holly Rushmeier}, publisher = {Eurographics}, pages = {125--136}, note = {ISBN 3-211-83535-0}, annote = {In composing hand-drawn images of 3D scenes, artists often alter the projection for each object in the scene independently, thereby generating multiprojection images. We present an interactive tool for creating such multiprojection images and animations, consisting of two parts: a multiprojection rendering algorithm and an interactive interface for attaching local cameras to the scene geometry. We describe a new set of techniques for resolving visibility between geometry rendered with different local cameras. We also develop several camera constraints that are useful when initially setting local camera parameters and when animating the scene. We demonstrate applications of our methods for generating a variety of artistic effects in still images and in animations. }, } @article{Hertzmann:2001:IA, author = {Aaron Hertzmann and Charles E. Jacobs and Nuria Oliver and Brian Curless and David H. Salesin}, title = {Image Analogies}, journal = {Proceedings of SIGGRAPH 2001}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {2001}, month = {August}, editor = {Eugene Fiume}, publisher = {ACM Press / ACM SIGGRAPH}, pages = {327--340}, note = {ISBN 1-58113-292-1}, keywords = {example-based rendering, texture synthesis, non-photorealistic rendering, Markov random fields, autoregression, texture-by-numbers, texture transfer}, annote = {This paper describes a new framework for processing images by example, called "image analogies." The framework involves two stages: a design phase, in which a pair of images, with one image purported to be a "filtered" version of the other, is presented as "training data"; and an application phase, in which the learned filter is applied to some new target image in order to create an "analogous" filtered result. Image analogies are based on a simple multi-scale autoregression, inspired primarily by recent results in texture synthesis. By choosing different types of source image pairs as input, the framework supports a wide variety of "image filter" effects, including traditional image filters, such as blurring or embossing; improved texture synthesis, in which some textures are synthesized with higher quality than by previous approaches; super-resolution, in which a higher-resolution image is inferred from a low-resolution source; texture transfer, in which images are "texturized" with some arbitrary source texture; artistic filters, in which various drawing and painting styles are synthesized based on scanned real-world examples; and texture-by-numbers, in which realistic scenes, composed of a variety of textures, are created using a simple painting interface. }, } @article{Baxter:2001:DIH, author = {Bill Baxter and Vincent Scheib and Ming C. Lin and Dinesh Manocha}, title = {DAB: Interactive Haptic Painting With 3D Virtual Brushes}, journal = {Proceedings of SIGGRAPH 2001}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {2001}, month = {August}, editor = {Eugene Fiume}, publisher = {ACM Press / ACM SIGGRAPH}, pages = {461--468}, note = {ISBN 1-58113-292-1}, keywords = {Haptics, Human Computer Interaction, Painting Systems, Deformable Brush Model}, annote = {We present a novel painting system with an intuitive haptic interface, which serves as an expressive vehicle for inter-ctively creating painterly works. We introduce a deformable, 3D brush model, which gives the user natural control of complex brush strokes. The force feedback enhances the sense of realism and provides tactile cues that enable the user to better manipulate the paint brush. We have also developed a bidirectional, two-layer paint model that, combined with a palette interface, enables easy loading of complex blends onto our 3D virtual brushes to generate interesting paint effects on the canvas. The resulting system, DAB, provides the user with an artistic setting, which is conceptually equivalent to a real-world painting environment. Several users have tested DAB and were able to start creating original art work within minutes. }, } @article{Hausner:2001:SDM, author = {Alejo Hausner}, title = {Simulating Decorative Mosaics}, journal = {Proceedings of SIGGRAPH 2001}, year = {2001}, month = {August}, editor = {Eugene Fiume}, publisher = {ACM Press / ACM SIGGRAPH}, pages = {573--578}, note = {ISBN 1-58113-292-1}, annote = {This paper presents a method for simulating decorative tile mosaics. Such mosaics are challenging because the square tiles that comprise them must be packed tightly and yet must follow orientations chosen by the artist. Based on an existing image and user-selected edge features, the method can both reproduce the image's colours and emphasize the selected edges by placing tiles that follow the edges. The method uses centroidal voronoi diagrams which normally arrange points in regular hexagonal grids. By measuring distances with an manhattan metric whose main axis is adjusted locally to follow the chosen direction field, the centroidal diagram can be adapted to place tiles in curving square grids instead. Computing the centroidal voronoi diagram is made possible by leveraging the z-buffer algorithm available in many graphics cards. }, } @article{Praun:2001:RH, author = {Emil Praun and Hugues Hoppe and Matthew Webb and Adam Finkelstein }, title = {Real-Time Hatching}, journal = {Proceedings of SIGGRAPH 2001}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {2001}, month = {August}, editor = {Eugene Fiume}, publisher = {ACM Press / ACM SIGGRAPH}, pages = {579--584}, note = {ISBN 1-58113-292-1}, keywords = {non-photorealistic rendering, line art, multitexturing, chicken-and-egg problem }, annote = {Drawing surfaces using hatching strokes simultaneously conveys material, tone, and form. We present a real-time system for non-photorealistic rendering of hatching strokes over arbitrary surfaces. During an automatic preprocess, we construct a sequence of mip-mapped hatch images corresponding to different tones, collectively called a tonal art map. Strokes within the hatch images are scaled to attain appropriate stroke size and density at all resolutions, and are organized to maintain coherence across scales and tones. At runtime, hardware multitexturing blends the hatch images over the rendered faces to locally vary tone while maintaining both spatial and temporal coherence. To render strokes over arbitrary surfaces, we build a lapped texture parametrization where the overlapping patches align to a curvature-based direction field. We demonstrate hatching strokes over complex surfaces in a variety of styles. }, } @article{Sourin:2001:FBV, author = {Alexei Sourin}, title = {Functionally Based Virtual Computer Art}, journal = {2001 ACM Symposium on Interactive 3D Graphics}, year = {2001}, month = {March}, editor = {John F. Hughes and Carlo H. S{\'{e}}quin}, pages = {77--84}, note = {ISBN 1-58113-292-1}, keywords = {Computer art, embossing, carving, virtual reality, functionally based shape modeling}, annote = {This article describes how virtual embossing and wood cutting can be done using the function representation of a shape and tools. The software is implemented as an interactive shape modeler where a functional model of the shape is subsequently modified with offset and set-theoretic operations. For visualization, interactive ray tracing is used. Bounding boxes together with the spatial organization of the functional model provide the required fast function evaluation that is usually a bottleneck for functionally based shape modeling systems. The software runs on a personal computer. }, } @article{Keefe:2001:CAF, author = {Daniel F. Keefe and Daniel Acevedo Feliz and Tomer Moscovich and David H. Laidlaw and Joseph J. LaViola Jr.}, title = {CavePainting: A Fully Immersive 3D Artistic Medium and Interactive Experience}, journal = {2001 ACM Symposium on Interactive 3D Graphics}, year = {2001}, month = {March}, editor = {John F. Hughes and Carlo H. S{\'{e}}quin}, pages = {85--94}, note = {ISBN 1-58113-292-1}, keywords = {3D painting, 3D modeling, gestures, tangible user interface, Cave}, annote = {CavePainting is an artistic medium that uses a 3D analog of 2D brush strokes to create 3D works of art in a fully immersive Cave environment. Physical props and gestures are used to provide an intuitive interface for artists who may not be familiar with virtual reality. The system is designed to take advantage of the 8 ft. × 8 ft. × 8 ft. space in which the artist works. CavePainting enables the artist to create a new type of art and provides a novel approach to viewing this art after it has been created. In this paper, we describe Cave-Painting s 3D brush strokes, color pickers, artwork viewing mode, and interface. We also present several works of art created using the system along with feedback from artists. Artists are excited about this form of art and the gestural, full-body experience of creating it. }, } @article{Yen:2001:ESC, author = {Jane Yen and Carlo S{\'{e}}quin}, title = {Escher Sphere Construction Kit}, journal = {2001 ACM Symposium on Interactive 3D Graphics}, year = {2001}, month = {March}, editor = {John F. Hughes and Carlo H. S{\'{e}}quin}, pages = {95--98}, note = {ISBN 1-58113-292-1}, keywords = {M. C. Escher, solid modeling, tessellation, spherical symmetry, spherical tiling, tile editor}, annote = {M. C. Escher created a myriad of amazing planar tessellations, yet only a few three-dimensional ones such as his wooden fish ball and dodecahedral flower. We have developed an interactive program to design and manufacture "Escher Spheres" - sets of tiles that can be assembled into spherical balls. The user chooses from a set of predefined symmetry groups and then deforms the boundaries of the basic domain tile; all corresponding points based on the chosen symmetry class move concurrently, instantly showing the overall result. The interior of the tile can be embellished with a bas-relief. Finally the tile is radially extruded and output as a solid model suitable for free-form fabrication. }, } @article{Kowalski:2001:UCE, author = {Michael A. Kowalski and John F. Hughes and Cynthia Beth Rubin and Jun Ohya}, title = {User-Guided Composition Effects For Art-Based Rendering }, journal = {2001 ACM Symposium on Interactive 3D Graphics}, year = {2001}, month = {March}, editor = {John F. Hughes and Carlo H. S{\'{e}}quin}, pages = {99--102}, note = {ISBN 1-58113-292-1}, } @article{Mohr:2001:NIS, author = {Alex Mohr and Michael Gleicher}, title = {Non-Invasive, Interactive, Stylized Rendering}, journal = {2001 ACM Symposium on Interactive 3D Graphics}, year = {2001}, month = {March}, editor = {John F. Hughes and Carlo H. S{\'{e}}quin}, pages = {175--178}, note = {ISBN 1-58113-292-1}, keywords = {Non-photorealistic rendering, Real-time, Stylized, Interactive, 3D}, annote = {In this paper, we show how many interactive 3D applications visual styles can be changed to new, different, and interesting visual styles non-invasively. Our method lets a single stylized renderer be used with many applications. We implement this by intercepting the OpenGL graphics library and changing the drawing calls. Even though OpenGL only receives low-level information from an application, computation on this data and assumptions about the application can give us enough information to develop stylized renderers. }, } @article{Igarashi:2001:AUF, author = {Takeo Igarashi and Dennis Cosgrove}, title = {Adaptive Unwrapping for Interactive Texture Painting}, journal = {2001 ACM Symposium on Interactive 3D Graphics}, year = {2001}, month = {March}, editor = {John F. Hughes and Carlo H. S{\'{e}}quin}, pages = {209--216}, note = {ISBN 1-58113-292-1}, keywords = {texture mapping, texture painting, interactive 3D graphics, multiresolution paint, zooming, 3D content creation}, annote = {We present a method for dynamically generating an efficient texture bitmap and its associated UV-mapping in an interactive texture painting system for 3D models. Typical 3D texture painting programs require the user to explicitly define the underlying UV-mapping from 3D geometry to 2D bitmap prior to painting. This mapping is unchanged by the painting process. However, a predefined UV-mapping can cause distortion at arbitrary locations and waste bitmap memory in unpainted areas. To solve these problems, we propose an adaptive unwrapping mechanism where the system dynamically creates a tailored UV-mapping for newly painted polygons during the interactive painting process. This eliminates the distortion of brush strokes, and the resulting texture bitmap is more compact because the system allocates texture space only for the painted polygons. In addition, this dynamic texture allocation allows the user to paint smoothly at any zoom level. This technique can be efficiently implemented using standard 3D rendering engines, and the painted models can be stored as standard textured polygonal models. We implemented a prototype system, called Chameleon, and our users experiences suggest that our technique is very useful for simple painting by casual users. }, } @article{Tolba:2001:APD, author = {Osama Tolba and Julie Dorsey and Leonard McMillan}, title = {A Projective Drawing System}, journal = {2001 ACM Symposium on Interactive 3D Graphics}, year = {2001}, month = {March}, editor = {John F. Hughes and Carlo H. S{\'{e}}quin}, pages = {25--34}, note = {ISBN 1-58113-292-1}, keywords = {Image-based Modeling and Rendering, Misc. 2D graphics, Non-Euclidean Spaces, Non-Photorealistic Rendering}, annote = {We present a novel drawing system for composing and rendering perspective scenes. Our approach uses a projective 2D representation for primitives rather than a conventional 3D description. This allows drawings to be composed with the same ease as traditional illustrations, while providing many of the advantages of a 3D model. We describe a range of user-interface tools and interaction techniques that give our system its 3D-like capabilities. We provide vanishing point guides and perspective grids to aid in drawing free-hand strokes and composing perspective scenes. Our system also has tools for intuitive navigation of a virtual camera, as well as methods for manipulating drawn primitives so that they appear to undergo 3D translations and rotations. We also support automatic shading of primitives using either realistic or non-photorealistic styles. Our system supports drawing and shading of extrusion surfaces with automatic hidden surface removal and highlighted silhouettes. Casting shadows from an infinite light source is also possible with minimal user intervention. }, } @inproceedings{Buchanan:2000:NPAR, author = {John W. Buchanan and Mario C. Sousa}, title = {The edge buffer: A data structure for easy silhouette rendering}, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @inproceedings{Buck:2000:NPAR, author = {Ian Buck and Adam Finkelstein and Charles Jacobs and Allison Klein and David H. Salesin and Jashua Seims and Richard Szeliski and Kentaro Toyama}, title = { Performance-Driven Hand-Drawn Animation}, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @inproceedings{Cohen:2000:NPAR, author = {Jonathan M. Cohen and John F. Hughes and Robert C. Zeleznik}, title = { Harold: A World Made of Drawings}, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @article{Deussen:2000, author = {Oliver Deussen and Thomas Strothotte}, title = {Computer-Generated Pen-and-Ink Illustration of Trees}, journal = {Proceedings of SIGGRAPH 2000}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {2000}, month = {July}, editor = {Kurt Akeley}, publisher = {ACM Press / ACM SIGGRAPH / Addison Wesley Longman}, pages = {13--18}, note = {ISBN 1-58113-208-5}, keywords = {Biological Systems, Frame Buffer Tricks, Non-Realistic Rendering}, annote = {We present a method for automatically rendering pen-and-ink illustrations of trees. A given 3-d tree model is illustrated by the tree skeleton and a visual representation of the foliage using abstract drawing primitives. Depth discontinuities are used to determine what parts of the primitives are to be drawn; a hybrid pixel-based and analytical algorithm allows us to deal efficiently with the complex geometric data. Using the proposed method we are able to generate illustrations with different drawing styles and levels of abstraction. The illustrations generated are spatial coherent, enabling us to create animations of sketched environments. Applications of our results are found in architecture, animation and landscaping. }, } @inproceedings{Girshick:2000:NPAR, author = {Ahna Girshick and Victoria Interrante and Steven Haker and Todd Lemoine}, title = {Line Direction Matters: An Argument for the Use of Principal Directions in 3D Line Drawings }, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @inproceedings{Hertzmann:2000:NPAR, author = {Aaron Hertzmann and Ken Perlin}, title = { Painterly Rendering for Video and Interaction}, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @article{Kaplan:2000:E, author = {Craig S. Kaplan and David H. Salesin}, title = {Escherization}, journal = {Proceedings of SIGGRAPH 2000}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {2000}, month = {July}, editor = {Kurt Akeley}, publisher = {ACM Press / ACM SIGGRAPH / Addison Wesley Longman}, pages = {499--510}, note = {ISBN 1-58113-208-5}, keywords = {Tilings, tesselations, morphing, optimization, simulated annealing, Escher}, annote = {This paper introduces and presents a solution to the ' Escherization' problem: given a closed figure in the plane, find a new closed figure that is similar to the original and tiles the plane. Our solution works by using a simulated annealer to optimize over a parameterization of the "isohedral" tilings, a class of tilings that is flexible enough to encompass nearly all of Escher's own tilings, and yet simple enough to be encoded and explored by a computer. We also describe a representation for isohedral tilings that allows for highly interactive viewing and rendering. We demonstrate the use of these tools - along with several additional techniques for adding decorations to tilings - with a variety of original ornamental designs. }, } @inproceedings{Kaplan:2000:NPAR, author = {Matthew Kaplan and Bruce Gooch and Elaine Cohen }, title = {Interactive Artistic Rendering }, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @inproceedings{Lake:2000:NPAR, author = {Adam Lake and Carl Marshall and Mark Harris and Marc Blackstein}, title = { Stylized Rendering Techniques for Scalable Real-Time 3D Animation}, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @inproceedings{Markosian:2000:NPAR, author = {Lee Markosian and Barbara J. Meier and Michael A. Kowalski and Loring S. Holden and J.D. Northrup and John F. Hughes}, title = { Art-based Rendering with Continuous Levels of Detail}, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @inproceedings{Martin:2000:NPAR, author = {D. Martin and S. Garcia and J. C. Torres}, title = { Observer dependent deformations in illustration}, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @article{Mestetskii:2000:FCA, author = {L.M. Mestetskii}, title = {Fat curves and representation of planar figures}, volume = {24}, number = {1}, journal = {Computers \& Graphics}, year = {February 2000}, publisher = {Pergamon Press / Elsevier Science}, pages = {9--21}, note = {ISSN 0097-8493}, keywords = {Fat curve; B{\'{e}}zier curve; Implicit representation; Engraving}, annote = {A fat curve is a "curve having a width;" it is the trace left by a moving circle of variable radius. A union of a finite number of fat curves is called engraving. This paper describes mathematical representation of fat curves, their rendering on standard (raster) display devices, proposes a B{\'{e}}zier representation for fat curves and discusses 2D modelling through engraving. A method for the approximation of arbitrary bitmap binary images by engraving is also presented. }, } @inproceedings{Northrup:2000:NPAR, author = {J.D. Northrup and Lee Markosian}, title = { Artistic Silhouettes: A Hybrid Approach}, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @inproceedings{Noot:2000:NPAR, author = {Han Noot and Zsofia Ruttkay}, title = { Animated CharToon Faces}, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @inproceedings{Snibbe:2000:NPAR, author = {Scott Sona Snibbe and Golan Levin}, title = { Interactive Dynamic Abstraction}, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="", } @article{Sousa:2000:OMO, author = {Mario Costa Sousa and John W. Buchanan}, title = {Observational Models of Graphite Pencil Materials}, volume = {19}, number = {1}, journal = {Computer Graphics Forum}, year = {2000}, month = {March}, publisher = {Blackwell Publishers}, pages = {27--49}, note = {ISSN 1067-7055}, annote = {This paper presents models for graphite pencil, drawing paper, blenders, and kneaded eraser that produce realistic looking pencil marks, textures, and tones. Our models are based on an observation of how lead pencils interact with drawing paper, and on the absorptive and dispersive properties of blenders and erasers interacting with lead material deposited over drawing paper. The models consider parameters such as the particle composition of the lead, the texture of the paper, the position and shape of the pencil materials, and the pressure applied to them. We demonstrate the capabilities of our approach with a variety of images and compare them to digitized pencil drawings. We also present image-based rendering results implementing traditional graphite pencil tone rendering methods. }, } @article{Deussen:2000:SIG, author = {Oliver Deussen and Thomas Strothotte}, title = {Pen-and-Ink Illustration of Trees}, journal = {Proceedings of SIGGRAPH 2000}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {July 2000}, editor = {}, publisher = {ACM SIGGRAPH}, pages = {}, note = {Held in New Orleans, Louisianna.}, keywords = {}, annote = { }, } @article{Klein:2000:SIG, author = {Allison W. Klein and Wilmot Li and Misha Kazhdan and Wagner Toledo Corrêa and Adam Finkelstein and Thomas Funkhouser }, title = {Non-Photorealistic Virtual Environments }, journal = {Proceedings of SIGGRAPH 2000}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {July 2000}, editor = {}, publisher = {ACM SIGGRAPH}, pages = {}, note = {Held in New Orleans, Louisianna.}, keywords = {}, annote = { }, } @article{Petrovic:2000:SIG, author = {Lena Petrovic and Brian Fujito and Adam Finkelstein and Lance Williams }, title = {Shadows for Cel Animation}, journal = {Proceedings of SIGGRAPH 2000}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {July 2000}, editor = {}, publisher = {ACM SIGGRAPH}, pages = {}, note = {Held in New Orleans, Louisianna.}, keywords = {}, annote = { }, } @article{Sander:2000:SIG, author = {Pedro V. Sander and Xianfeng Gu and Steven J. Gortler and Hugues Hoppe and John Snyder }, title = {Silhouette Clipping}, journal = {Proceedings of SIGGRAPH 2000}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {July 2000}, editor = {}, publisher = {ACM SIGGRAPH}, pages = {}, note = {Held in New Orleans, Louisianna.}, keywords = {}, annote = { }, } @article{Zorin:2000:SIG, author = {Aaron Hertzmann and Denis Zorin }, title = {Illustrating Smooth Surfaces}, journal = {Proceedings of SIGGRAPH 2000}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {July 2000}, editor = {}, publisher = {ACM SIGGRAPH}, pages = {}, note = {Held in New Orleans, Louisianna.}, keywords = {}, annote = { }, } @inproceedings{Shiraishi:NPAR00, author = {Michio Shiraishi and Yasushi Yamaguchi }, title = { An Algorithm for Automatic Painterly Rendering based on Local Source Image Approximation}, booktitle ={Non-Photorealistic Animation and Rendering 2000 (NPAR '00)}, editor = {}, year = {June 5-7,2000}, publisher = {}, address = {Annecy, France}, pages = {}, abstract="This paper presents a new method for the automatic painterly rendering. This method synthesizes an impressive image with a hand crafted look from a source image such as a photograph. This method generates rectangular brush strokes approximating the local regions of the source image with suitable locations, orientations, and sizes. These properties are calculated with the image moments of the color difference images, obtained by taking the difference between the local source images, and the stroke colors. The method explicitly deals with not only intensity but also chromaticity of the source image. The resulting image is composited with smaller strokes at the details while its flat regions are painted with larger ones. The method is also able to control the density of strokes as well as their painting order based on their sizes. The density is controlled by a dithering method with space-filling curves. Painting process starts from the larger strokes and finishes with the finer ones. Because of the density control and the painting order the final image preserves the details of the source image.", } @article{Winter2000, author = {RobertWinter}, title = {Art by the Numbers}, journal = {UCLA Magazine}, year = {Spring 2000}, editor = {}, pages = {26--31}, note = {} } @article{Barequet:1999, author = {G. Barequet and C. A. Duncan and M. T. Goodrich and S. Kumar and M. Pop}, title = {Efficient perspective-accurate silhouette computation}, journal = {Proceedings of the fifteenth annual symposium on Computational Geometry}, year = {1999}, editor = {}, pages = {417--418}, note = {} } @article{Deussen:1999:AIT, author = {Oliver Deussen and Joerg Harnel and Andreas Raab and Stefan Schlechtweg and Thomas Strothotte}, title = {An Illustration Technique Using Hardware-Based Intersections}, journal = {Graphics Interface '99}, year = {June 1999}, editor = {I. Scott MacKenzie and James Stewart}, pages = {175--182}, note = {ISBN 1-55860-632-7}, keywords = {Non-Photorealistic Rendering, Illustration Techniques, Arts, Graphics Hardware}, annote = {We present a method for generating line drawings of complex geometries in the style of crosshatched illustrations. Hatching lines are generated by intersecting the geometry with a set of planes. Half-toning on the basis of the generated curves is used to represent a given intensity distribution. Computing a geometric skeleton allows us to determine automatically the orientation of the intersection planes for a wide variety of models. By using predefined line styles different types of illustrations can be generated. Applications of the method are discussed, examples are given. }, } @Article{NPRCourse99, Author = "Stuart Green and David Salesin and Simon Schofield and Aaron Hertzmann and Peter Litwinowicz and Amy Gooch and Cassidy Curtis and Bruce Gooch.", Title = "{Non-Photorealistic Rendering}", Journal= {SIGGRAPH '99 Non-Photorealistic Rendering Course Notes}, Year = 1999, } @Article{OpenGLCourse99, Author = "David Blythe and Brad Grantham and Tom McReynolds and Scott R. Nelson", Title = "{Advanced Graphics Programming Techniques Using OpenGL}", Journal= {SIGGRAPH '99 Course}, Year = 1999, } @Article{gooc99, Author = "Bruce Gooch and Peter-Pike Sloan and Amy Gooch and Peter Shirley and Richard Riesenfeld", Title = "{Interactive Technical Illustration}", Journal= {Interactive 3D Conference Proceedings}, Year = 1999, Volume = {}, Number = {}, Month = apr, annote = {A rendering is an abstraction that favors, preserves, or even emphasizes some qualities while sacrificing, suppressing, or omitting other characteristics that are not the focus of attention. Most computer graphics rendering activities have been concerned with photorealism, i.e., trying to emulate an image that looks like a high-quality photograph. This laudable goal is useful and appropriate in many applications, but not in technical illustration where elucidation of structure and technical information is the preeminent motivation. This calls for a different kind of abstraction in which technical communication is central, but art and appearance are still essential instruments toward this end. Work that has been done on computer generated technical illustrations has focused on static images, and has not included all of the techniques used to hand draw technical illustrations. A paradigm for the display of technical illustrations in a dynamic environment is presented. This display environment includes all of the benefits of computer generated technical illustrations, such as a clearer picture of shape, structure, and material composition than traditional computer graphics methods. It also includes the three-dimensional interactive strength of modern display systems. This is accomplished by using new algorithms for real time drawing of silhouette curves, algorithms which solve a number of the problems inherent in previous methods. We incorporate current non-photorealistic lighting methods, and augment them with new shadowing algorithms based on accepted techniques used by artists and studies carried out in human perception. }, } @article{Hamel:1999:CAR, author = {J. Hamel and T. Strothotte}, title = {Capturing and Re-Using Rendition Styles for Non-Photorealistic Rendering}, volume = {18}, number = {3}, journal = {Computer Graphics Forum}, year = {September 1999}, publisher = {Blackwell Publishers}, pages = {173--182}, note = {ISSN 1067-7055}, annote = {Rendering high-quality non-photorealistic images of a given geometric model is often associated with a considerable amount of effort on the part of a user to fine-tune the rendition. In this paper we introduce a method and tools for re-using the user's effort invested in one model for the rendering of other models.\\Our method uses templates to describe rendition styles. The paper gives a number of examples of the successful transfer of styles from one model to another. }, } @article{Igarashi:1999:TAS, author = {Takeo Igarashi and Satoshi Matsuoka and Hidehiko Tanaka}, title = {Teddy: A Sketching Interface for 3D Freeform Design}, journal = {Proceedings of SIGGRAPH 99}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {August 1999}, editor = {Alyn Rockwood}, publisher = {Addison Wesley Longman}, pages = {409--416}, note = {ISBN 0-20148-560-5. Held in Los Angeles, California.}, keywords = {3D modeling, sketching, pen-based systems, gestures, design, chordal axes, inflation}, annote = {We present a sketching interface for quickly and easily designing freeform models such as stuffed animals and other rotund objects. The user draws several 2D freeform strokes interactively on the screen and the system automatically constructs plausible 3D polygonal surfaces. Our system supports several modeling operations, including the operation to construct a 3D polygonal surface from a 2D silhouette drawn by the user: it inflates the region surrounded by the silhouette making wide areas fat, and narrow areas thin. Teddy, our prototype system, is implemented as a Java program, and the mesh construction is done in real-time on a standard PC. Our informal user study showed that a first-time user typically masters the operations within 10 minutes, and can construct interesting 3D models within minutes. }, } @article{Kowalski:1999:ARO, author = {Michael A. Kowalski and Lee Markosian and J. D. Northrup and Lubomir Bourdev and Ronen Barzel and Loring S. Holden and John Hughes}, title = {Art-Based Rendering of Fur, Grass, and Trees}, journal = {Proceedings of SIGGRAPH 99}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {August 1999}, editor = {Alyn Rockwood}, publisher = {Addison Wesley Longman}, pages = {433--438}, note = {ISBN 0-20148-560-5. Held in Los Angeles, California.}, keywords = {Non-photorealistic rendering, graftals, procedural textures}, annote = {Artists and illustrators can evoke the complexity of fur or vegetation with relatively few well-placed strokes. We present an algorithm that uses strokes to render 3D computer graphics scenes in a stylized manner suggesting the complexity of the scene without representing it explicitly. The basic algorithm is customizable to produce a range of effects including fur, grass and trees, as we demonstrate in this paper and accompanying video. The algorithm is implemented within a broader framework that supports procedural stroke-based textures on polyhedral models. It renders mod-erately complex scenes at multiple frames per second on current graphics workstations, and provides some interframe coherence. }, } @article{Markosian:1999:SAC, author = {Lee Markosian and Jonathan M. Cohen and Thomas Crulli and John F. Hughes}, title = {Skin: A Constructive Approach to Modeling Free-form Shapes}, journal = {Proceedings of SIGGRAPH 99}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {August 1999}, editor = {Alyn Rockwood}, publisher = {Addison Wesley Longman}, pages = {393--400}, note = {ISBN 0-20148-560-5. Held in Los Angeles, California.}, keywords = {Free-form modeling, meshes, subdivision, multiresolution}, annote = {We present a new particle-based surface representation with which a user can interactively sculpt free-form surfaces. The particles maintain mesh connectivity and operate under rules that lead them to form triangulations with properties that make them suitable for use in subdivision. A user interactively guides the particles, which we call skin, to grow over a given collection of polyhedral elements (or skeletons), yielding a smooth surface (through subdivision) that approximates the underlying skeletal shapes. Skin resembles blobby modeling in the constructive approach to modeling it supports, but allows a richer vocabulary of skeleton shapes, supports sharp creases where desired, and provides a convenient mechanism for adding multiresolution surface detail. }, } @article{Ostromoukhov:1999:DFE, author = {Victor Ostromoukhov}, title = {Digital Facial Engraving}, journal = {Proceedings of SIGGRAPH 99}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {August 1999}, editor = {Alyn Rockwood}, publisher = {Addison Wesley Longman}, pages = {417--424}, note = {ISBN 0-20148-560-5. Held in Los Angeles, California.}, keywords = {photorealistic rendering, nonphotorealistic rendering, halftoning, dithering, digital engraving}, annote = {This contribution introduces the basic techniques for digital facial engraving, which imitates traditional copperplate engraving. Inspired by traditional techniques, we first establish a set of basic rules thanks to which separate engraving layers are built on the top of the original photo. Separate layers are merged according to simple merging rules and according to range shift/scale masks specially introduced for this purpose. We illustrate the introduced technique by a set of black/white and color engravings, showing different features such as engraving-specific image enhancements, mixing different regular engraving lines with mezzotint, irregular perturbations of engraving lines etc. We introduce the notion of engraving style which comprises a set of separate engraving layers together with a set of associated range shift/scale masks. The engraving style helps to port the look and feel of one engraving to another. Once different libraries of pre-defined mappable engraving styles and an appropriate user interface are added to the basic system, producing a decent gravure starting from a simple digital photo will be a matter of seconds. The engraving technique described in this contribution opens new perspectives for digital art, adding unprecedented power and precision to the engraver's work. }, } @article{Ostromoukhov:1999:MAA, author = {Victor Ostromoukhov and Roger D. Hersch}, title = {Multi-Color and Artistic Dithering}, journal = {Proceedings of SIGGRAPH 99}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {1999}, month = {August}, editor = {Alyn Rockwood}, publisher = {Addison Wesley Longman}, pages = {425--432}, note = {ISBN 0-20148-560-5. Held in Los Angeles, California.}, keywords = {color halftoning, artistic dithering, dither matrix equilibration, non-standard inks, side by side printing}, annote = {A multi-color dithering algorithm is proposed, which converts a barycentric combination of color intensities into a multi-color non-overlapping surface coverage. Multi-color dithering is a generalization of standard bi-level dithering. Combined with tetrahedral color separation, multi-color dithering makes it possible to print images made of a set of non-standard inks. In contrast to most previous color halftoning methods, multi-color dithering ensures by construction that the different selected basic colors are printed side by side. Multi-color dithering is applied to generate color images whose screen dots are made of artistic shapes (letters, symbols, ornaments, etc.). Two dither matrix postprocessing techniques are developed, one for enhancing the visibility of screen motives and one for the local equilibration of large dither matrices. The dither matrix equilibration process corrects disturbing local intensity variations by taking dot gain and the human visual system transfer function into account. Thanks to the combination of the presented techniques, high quality images can be produced, which incorporate at the micro level the desired artistic screens and at the macro level the full color image. Applications include designs for advertisements and posters as well as security printing. Multi-color dithering also offers new perspectives for printing with special inks, such as fluorescent and metallic inks. }, } @article{Rademacher:1999:VDG, author = {Paul Rademacher}, title = {View-Dependent Geometry}, journal = {Proceedings of SIGGRAPH 99}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {August 1999}, editor = {Alyn Rockwood}, publisher = {Addison Wesley Longman}, pages = {439--446}, note = {ISBN 0-20148-560-5. Held in Los Angeles, California.}, keywords = {Cartoon animation, 3D animation, rendering, animation systems, non-photorealistic rendering, 3D blending}, annote = {When constructing 3D geometry for use in cel animation, the reference drawings of the object or character often contain various view-specific distortions, which cannot be captured with conventional 3D models. In this work we present a technique called View-Dependent Geometry, wherein a 3D model changes shape based on the direction it is viewed from. A view-dependent model consists of a base model, a set of key deformations (deformed versions of the base model), and a set of corresponding key viewpoints (which relate each 2D reference drawing to the 3D base model). Given an arbitrary viewpoint, our method interpolates the key deformations to generate a 3D model that is specific to the new viewpoint, thereby capturing the view-dependent distortions of the reference drawings. }, } @InProceedings{raskar-temp, author= "Ramesh Raskar and Michael Cohen", title = "Image {P}recision {S}ilhouette {E}dges", booktitle = "Proc. 1999 ACM Symposium on Interactive 3D Graphics", year = "1999", month = apr, annote = {Finding and displaying silhouette edges is important in applications ranging from computer vision to nonphotorealistic rendering. To render visible silhouette edges of a polygonal object in a scene from a given viewpoint, we must first find all silhouette edges, i.e. boundaries between adjacent front facing and back-facing surfaces. This is followed by solving the partial visibility problem so that only those parts of silhouette edges, which are not occluded by interior of any front facing surface, are rendered. The scene may optionally be rendered with a lighting model. This paper describes a simple general-purpose method to combine all three operations for any scene composed of objects that can be scan-converted. Using a depth buffer, the rendering process computes the intersection of adjacent front facing and back-facing surfaces in image space at interactive rates. All operations are performed in image-precision and hence special care is taken for the limited numerical precision of the depth buffer. A solution is suggested using view-dependent modification of polygonal objects. The method does not require any preprocessing or adjacency information and hence is applicable for dynamic scenes.}, } @TechReport{Shira:1999, author = "Michio Shiraishi and Yasushi Yamaguchi", title = "Image Moment-Based Stroke Placement", year = "1999", month = May, pages = "1--3", keywords = "image, moment, paint, art, artistic ", number = "skapps3794", institution = "University of Tokyo", address ="Tokyo Japan", abstract = "Painterly rendering algorithms synthesize the images with a hand-crafted touch from a source image of a real scene. The current major scheme is based on Haeberli's method, which paints brush strokes on a canvas successively. In our approach, each rectangular stroke is controlled by several attributes, namely, color, location, orientation, width, and length. We propose an alternative method to determine these attributes so that the stroke nicely approximates a local region of the source image.", annote = " This paper presents a method of using image moments to capture the color, size, orientation, and a rough idea of the texture needed for strokes in an automatic painting system. Much of the math and a good breakdown of the algorithm are presented.", } @article{Sousa:1999:CGP, author = {Mario Costa Sousa and John W. Buchanan}, title = {Computer-Generated Graphite Pencil Rendering of 3D Polygonal Models}, volume = {18}, number = {3}, journal = {Computer Graphics Forum}, year = {September 1999}, pages = {195--208}, annote = {Researchers in non-photorealistic rendering have investigated the display of three-dimensional worlds using various display models. In particular, recent work has focused on the modeling of traditional artistic media and styles such as pen-and-ink illustration and watercolor painting. By providing 3D rendering systems that use these alternative display models users can generate traditional illustration renderings of their three-dimensional worlds. In this paper we present our graphite pencil 3D renderer. We have broken the problem of simulating pencil drawing down into four fundamental parts: (1) simulating the drawing materials (graphite pencil and drawing paper, blenders and kneaded eraser), (2) modeling the drawing primitives (individual pencil strokes and mark-making to create tones and textures), (3) simulating the basic rendering techniques used by artists and illustrators familiar with pencil rendering, and (4) modeling the control of the drawing composition. Each part builds upon the others and is essential to developing the framework for higher-level rendering methods and tools. In this paper we present parts 2, 3, and 4 of our research. We present non-photorealistic graphite pencil rendering methods for outlining and shading. We also present the control of drawing steps from preparatory sketches to finished rendering results. We demonstrate the capabilities of our approach with a variety of images generated from 3D models. }, } @article{Sousa:1999:NRO, author = {Mario Costa Sousa and John W. Buchanan}, title = {Observational Model of Blenders and Erasers in Computer-Generated Pencil Rendering}, journal = {Graphics Interface '99}, year = {1999}, month = {June}, editor = {I. Scott MacKenzie and James Stewart}, pages = {157--166}, note = {ISBN 1-55860-632-7}, annote = {In this paper we present a blender and eraser model that extends our graphite pencil and paper model. This blender and eraser model enhances the rendering results producing realistic looking graphite pencil tones and textures. Our model is based on observations on the absorptive and dispersive properties of blenders and erasers interacting with lead material deposited over drawing paper. The parameters of our model are the particle composition of the lead over the paper, the texture of the paper, the position and shape of the blender and eraser, and the pressure applied to them. We demonstrate the capabilities of our approach with a variety of pencil swatches and compare them to digitized pencil drawings. We also present automatic and interactive image-based rendering results implementing traditional graphite pencil tone rendering methods. }, } @article{Takagi:1999:VMO, author = {Saeko Takagi and Masayuki Nakajima and Issei Fujishiro}, title = {Volumetric Modeling of Colored Pencil Drawing}, journal = {Pacific Graphics '99}, year = {1999}, month = {October}, note = {Held in Seoul, Korea.}, } @article{Tumblin:1999:TMF, author = {Jack Tumblin and Greg Turk}, title = {LCIS: A Boundary Hierarchy for Detail-Preserving Contrast Reduction}, journal = {Proceedings of SIGGRAPH 99}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {August 1999}, editor = {Alyn Rockwood}, publisher = {Addison Wesley Longman}, pages = {83--90}, note = {ISBN 0-20148-560-5. Held in Los Angeles, California.}, keywords = {Signal Processing, Displays, Non-Realistic Rendering, Level Of Detail Algorithms, Radiosity, Weird Math}, annote = {High contrast scenes are difficult to depict on low contrast displays without loss of important fine details and textures. Skilled artists preserve these details by drawing scene contents in coarse-to-fine order using a hierarchy of scene boundaries and shadings. We build a similar hierarchy using multiple instances of a new low curvature image simplifier (LCIS), a partial differential equation inspired by anisotropic diffusion. Each LCIS reduces the scene to many smooth regions that are bounded by sharp gradient discontinuities, and a single parameter K chosen for each LCIS controls region size and boundary complexity. With a few chosen K values (K1 > K2 > K3...) LCIS makes a set of progressively simpler images, and image differences form a hierarchy of increasingly important details, boundaries and large features.\\ We construct a high detail, low contrast display image from this hierarchy by compressing only the large features, then adding back all small details. Unlike linear filter hierarchies such as wavelets, filter banks, or image pyramids, LCIS hierarchies do not smooth across scene boundaries, avoiding "halo" artifacts common to previous contrast reducing methods and some tone reproduction operators.\\ We demonstrate LCIS effectiveness on several example images. }, } @article{Veryovka:1999:HWI, author = {Oleg Veryovka and John W. Buchanan}, title = {Halftoning With Image-Based Dither Screens}, journal = {Graphics Interface '99}, year = {June 1999}, editor = {I. Scott MacKenzie and James Stewart}, pages = {167--174}, note = {ISBN 1-55860-632-7}, keywords = {Halftoning, texture processing, artistic screening, non-photorealistic rendering}, annote = {Continuous tone imaces must be halftoned to be displayed on binary output devices such as printers. The ordered dither algorithm is a popular approach to halftoning. This algorithm uses a threshold matrix to approximate gray scale values. The arrangement of thresholds in the matrix determines texture artifacts introduced into the halftoned image. Thus, the challenge of research in ordered dithering is to find a matrix that results in the least visible texture artifacts.\\ In this work we control the halftoning texture by generating a threshold matrix from an arbitrary image. We demonstrate that processing images using adaptive histogram equalization results in pixel distributions similar to traditional dither screens. Ordered dithering with the resulting threshold matrix enables us to define texture in the halftoned image. We control the appearance of this texture by a combination of the ordered dither algorithm with an error diffusion process.\\ We present applications of the image-based dither screens to both photorealistic and artistic rendering. In the case of photoreatistic tone reproduction this technique preserves textures and edges of the original imaae. The ability to define an arbitrary texture enables us to introduce a variety of artistic effects. A halftoned image can be embossed with another image, texture, or text. Also, halftoning with textures clipped from the existing art works approximates the look of traditional illustration media. }, } @mastersThesis{Wong:1999, author = "Eric Wong", title = "Artistic Rendering of Portrait Photographs", year = "1999", keywords = "image, portrait, photographs, rendering, paint, artistic ", school = "Cornell University", abstract = "In this thesis, we present a semi-automatic process to artistically render portrait photographs in a charcoal style. The software system requires the user to coach the process by identifying regions and edges in the portrait. With their information and a set of selected parameters, the user can quickly generate an artistic charcoal sketch. In general, our system produces a charcoal image by rendering the following five features of a portrait photograph: 1) the background area, 2) the hair, 3) the edges and lines, 4) the facial features, and 5) the facial tone. Although we compute the vertex points that compose the line segments in the final image, our system relies on an external software application to render these lines in a charcoal style. In order to render the hair region in the second process step above, we developed a novel image processing operation based on the Hough transform to find the orientation of each point tin the hair region. ", annote = " This thesis presents an interactive method for generating charcoal style drawn portraits. One thing to note is that quite a bit of user interaction is needed at each step in the process. Also, the idea of interactive portraits or animated portraits has not been addressed. One good note is the idea of having the level of abstraction match the stage of the design process was finally expressed. The software engineering on this thesis was well done, and the process is broken down into reasonable pieces that could be automated. In particular, the automation of later parts of the process may only depend on earlier parts being automated.", } @article{Zhang:1999:SCA, author = {Qing Zhang and Youetsu Sato and Jun-ya Takahashi and Kazunobu Muraoka and Norishige Chiba}, title = {Simple cellular automaton-based simulation of ink behaviour and its application to Suibokuga-like 3D rendering of trees}, volume = {10}, number = {1}, journal = {The Journal of Visualization and Computer Animation}, year = {January - March 1999}, publisher = {John Wiley & Sons}, pages = {27--37}, note = {ISSN 1049-8907}, keywords = {non-photorealistic rendering; Suibokuga-like rendering; simulation of ink diffusion; cellular automaton}, annote = {Suibokuga is a style of monochrome painting characterized by the use of Chinese black ink (sumi), a complex interaction between brush, ink and paper, and such visual features as Noutan (shade), Kasure (scratchiness), and Nijimi (blur). In this paper we present a simple behavioural model of water and ink particles based on a 2D cellular automaton computational model, and its application to a Suibokuga-like rendering of 3D trees. }, } @article{bremmer1998, author = { David J. Bremer and John F. Hughes }, title = {Rapid Approximate Silhouette Rendering of Implicit Surfaces}, journal = {Proceedings of Implicit Surfaces '98}, series = {}, year = {June 1998}, editor = {}, publisher = {}, pages = {155--164}, note = {}, keywords = {}, annote = {}, } @article{Correa:1998:TMF, author = {Wagner Toledo Corr{\^{e}}a and Robert J. Jensen and Craig E. Thayer and Adam Finkelstein}, title = {Texture Mapping for Cel Animation}, journal = {Proceedings of SIGGRAPH 98}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {July 1998}, editor = {Michael Cohen}, publisher = {Addison Wesley}, pages = {435--446}, note = {ISBN 0-89791-999-8. Held in Orlando, Florida.}, keywords = {Cel animation, texture mapping, silhouette detection, warp, metamorphosis, morph, non-photorealistic rendering}, annote = {We present a method for applying complex textures to hand-drawn characters in cel animation. The method correlates features in a simple, textured, 3-D model with features on a hand-drawn figure, and then distorts the model to conform to the hand-drawn artwork. The process uses two new algorithms: a silhouette detection scheme and a depth-preserving warp. The silhouette detection algorithm is simple and efficient, and it produces continuous, smooth, visible contours on a 3-D model. The warp distorts the model in only two dimensions to match the artwork from a given camera perspective, yet preserves 3-D effects such as self-occlusion and foreshortening. The entire process allows animators to combine complex textures with hand-drawn artwork, leveraging the strengths of 3-D computer graphics while retaining the expressiveness of traditional hand-drawn cel animation. }, } @mastersThesis{Coutts:1998, author = "Richard M. Coutts", title = "Conceptual modeling and rendering techniques for architectural design.", year = "1998", keywords = "image, portrait, photographs, rendering, paint, artistic ", school = "Cornell University", annote = {Todays design professions are not integrating the computer into their workplace as successfully as more technical professionals. It is tempting to attribute this to the fact that artists and architects are not as technically savvy as engineers and scientists. Closer inspection reveals, however, that current software applications simply do not fit their needs. Three problematic areas are identified in this thesis in current design software. (1) Human-computer interfaces are to cumbersome for design. (2) the current human-computer interfaces do not facilitate transitioning between conceptuall drawings and computer models. (3) Current omputer rendering styles are not abstract enough for visualizing incomplete designs. These shortcomings are alleviated here by introducing a new human acomputer interface and sketch rendering tecniques. A solid modeler was written for this thesis to address the human-computer interface issues. Currently, architects and designers use traditional media - e.g., clay, chipboard, and sketches - in preliminary design. For a solid modeler to ccompete with these materials, it must be as simple to use. Our modeler;s interface approaches this goal by incorporating a surface cursor that feels its way along the models surface, giving the designer much needed visuall cues as to the cursor's location in three diminsions. The need for more abstract rendering styles is addressed by presenting a new technique for generating sketch renderings. These renderings approximate the look and feel of conventional hand drawings. The algorithims presented here simulate an artist's hatch markings and vectored streamlines. The streamlines are calculated in a two dimentional vector field generated by projecting three dimensional surface flow onto the image plane. A global illumination image is used as a tone map to control the hatching density. Because the algorithims operate on strictly two-dimensional data extracted from the three-dimensional model, they are robust and simple to implement. Several new support algorithims, including a new one-pass streamline algorithim that approximates both denisity and direction, are described.}, } @InProceedings{Curtis98, author = "Cassidy Curtis", title = "Loose and {S}ketchy {A}nimation", booktitle = "SIGGRAPH 98: Conference Abstracts and Applications", year = "1998", pages = "317", annote = {In naritive charactor animaiton, engaging the viewer and conveying emotion and personality are of the highest importance. Early in the development of the medium, animators learned that an effective way to achieve these goals was to "present a unified single idea with nothing complicated extraneous, or contradictory in its makeup." But this principle is seldom applied successfully in computer animation because of the demands of photorealistic rendering. Photrealism , liike pornography, leaves nothing to the imagination. It presents the viewer with a world of objects omplete with volume and texture, which is far more information that the viewer needs to get the point. FFurthermore, unless great effort is devoted to every detail of modeling, shading, and lighting, much fo that information will actually contradict the central idea, distracting the viewer. The need to cancel out these spurious impressions places an unreasonable demand on the animator.}, } @Article{Elber:1998:LAI, author = "Gershon Elber", title = "Line {A}rt {I}llustrations of {P}arametric and {I}mplicit {F}orms", journal = "IEEE Transactions on Visualization and Computer Graphics", year = "1998", volume = "4", number = "1", month = jan # " -- " # mar, note = "ISSN 1077-2626", keywords = "Sketches, illustrations, line drawings, freeform surfaces, NURBs, implicit forms, surface coverage, printing", annote = "A technique is presented for line art rendering of scenes composed of freeform surfaces. The line art that is created for parametric surfaces is practically intrinsic and is globally invariant to changes in the surface parameterization. This method is equally applicable for line art rendering of implicit forms, creating a unified line art rendering method for both parametric and implicit forms. This added flexibility exposes a new horizon of special, parameterization independent, line art effects. Moreover, the production of the line art illustrations can be combined with traditional rendering techniques such as transparency and texture mapping. Examples that demonstrate the capabilities of the proposed approach are presented for both the parametric and implicit forms.", } @article{Gooch:1998:ANL, author = {Amy Gooch and Bruce Gooch and Peter Shirley and Elaine Cohen}, title = {A Non-Photorealistic Lighting Model for Automatic Technical Illustration}, journal = {Proceedings of SIGGRAPH 98}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {July 1998}, editor = {Michael Cohen}, publisher = {ACM SIGGRAPH}, pages = {447--452}, note = {ISBN 0-89791-999-8. Held in Orlando, Florida.}, keywords = {illustration, non-photorealistic rendering, silhouettes, lighting models, tone, color, shading}, annote = {Phong-shaded 3D imagery does not provide geometric information of the same richness as human-drawn technical illustrations. A non-photorealistic lighting model is presented that attempts to narrow this gap. The model is based on practice in traditional technical illustration, where the lighting model uses both luminance and changes in hue to indicate surface orientation, reserving extreme lights and darks for edge lines and highlights. The lighting model allows shading to occur only in mid-tones so that edge lines and highlights remain visually prominent. In addition, we show how this lighting model is modified when portraying models of metal objects. These illustration methods give a clearer picture of shape, structure, and material composition than traditional computer graphics methods. }, } @MastersThesis{Gooch:1998:thesis, Author="Gooch, Amy A.", School="University of Utah", Title="Interactive Non-photorealistic Technical Illustration", Year="1998", Month="December", Attributions = "", Abstract = "Current interactive modeling systems allow users to view models in wireframe or Phong-shaded images. However, the wireframe is based on the model's parameterization, and a model's features may get lost in a nest of lines. Alone, a fully rendered image may not provide enough useful information about the structure or model features. Human technical illustrators follow certain visual conventions that are unlike Phong-shaded or wireframe renderings, and the drawings they produce are subjectively superior to conventional computer renderings. This thesis explores lighting, shading, and line illustration conventions used by technical illustrators. These conventions are implemented in a modeling system to create a new method of displaying and viewing complex NURBS models. In particular, silhouettes and edge lines are drawn in a manner similar to pen-and-ink drawings, and a shading algorithm is used that is similar to ink-wash or air-brush renderings for areas inside the silhouettes. This shading has a low intensity variation so that the black silhouettes remain visually distinct, and it has a cool-to-warm hue transition to help accent surface orientation. Applying these illustration methods produces images that are closer to human-drawn illustrations than is provided by traditional computer graphics approaches.", } @article{Hertzmann:1998:PRW, author = {Aaron Hertzmann}, title = {Painterly Rendering with Curved Brush Strokes of Multiple Sizes}, journal = {Proceedings of SIGGRAPH 98}, year = {July 1998}, editor = {Michael Cohen}, pages = {453--460}, keywords = {non-photorealistic rendering}, annote = {We present a new method for creating an image with a hand-painted appearance from a photograph, and a new approach to designing styles of illustration. We "paint" an image with a series of spline brush strokes. \\ Brush strokes are chosen to match colors in a source image. A painting is built up in a series of layers, starting with a rough sketch drawn with a large brush. The sketch is painted over with progressively smaller brushes, but only in areas where the sketch differs from the blurred source image. Thus, visual emphasis in the painting corresponds roughly to the spatial energy present in the source image. We demonstrate a technique for painting with long, curved brush strokes, aligned to normals of image gradients. Thus we begin to explore the expressive quality of complex brush strokes. Rather than process images with a single manner of painting, we present a framework for describing a wide range of visual styles. A style is described as an intuitive set of parameters to the painting algorithm that a designer can adjust to vary the style of painting. We show examples of images rendered with different styles, and discuss long-term goals for expressive rendering styles as a general-purpose design tool for artists and animators. }, } @InProceedings{Masuch:1998:AFF, author = {Maic Masuch and Lars Schumann and Stefan Schlechtweg}, title = {{A}nimating {F}rame-to-{F}rame {C}onsistent {L}ine {D}rawings for {I}llustrative {P}urposes}, booktitle = {Simulation und Animation '98}, editor = {Peter Lorenz and Bernhard Preim}, year = {1998}, publisher = {SCS Europe}, address = {Erlangen, Ghent}, pages = {101--112}, annote = {We present a system for rendering 3D animations in the style of line drawings. We use a highly parameterized line model in order to determine the appearance of a line. This model allows us to render characteristic line deviations that remain--in contrast to existing non-photorealistic rendering systems--frame coherent. Other inconsistencies which result from intersection and visibility changes during an animation are prevented by a path reconstruction method. Furthermore, we implemented a keyframing for linestyle parameters which enables us to extend illustration techniques like simplification of a scene or the placement of emphasis on certain objects to the field of 3D computer animation. }, } @article{Snyder1998, author = {A. W. Snyder and H. B. Barlow}, title = {Revealing the artist's touch}, volume = {331}, number = {14}, journal = {Nature}, year = {1998}, editor = {}, publisher = {}, pages = {117--118}, annote = {Is there a unifying conceptual framework for understanding human visual-information processing, one that explains the occurence of illusions such as those of Ramachandran on page 163 of this issue? Or is it better to regard our visual system as a mosaic of unrelated strategies, one ffor every special taks? An animal needs to make rapid decisions about what objects are where in its surroundings, but it has only a few neurons at its disposal: this strongly suggests that eh brain should first simplify processing for detection and recognition fo objects, and then report its findings with the utmost economy. WE propose that these two principles provide a unifying interpretation of existing perceptual data and will enable us to place new results in a proper perspective.}, } @article{Streit:1998:IDH, author = {L. M. Streit and J. W. Buchanan}, title = {Importance Driven Halftoning}, volume = {17}, number = {3}, journal = {Computer Graphics Forum}, year = {1998}, editor = {N. Ferreira and M. G{\"{o}}bel}, publisher = {Blackwell Publishers}, pages = {207--218}, note = {ISSN 1067-7055}, keywords = {halftoning, bandpass pyramid, importance function, limited resource rendering, non-photorealistic rendering, traditional halftoning, drawing primitive, multiresolution representations}, annote = {Most halftoning techniques have been primarily concerned with achieving an accurate reproduction of local grayscale intensities while avoiding the introduction of artifacts. A second concern in halftoning has been the preservation of edges in the halftoned image. In this paper we will introduce a new halftoning technique that utilizes a bandpass pyramid to achieve an accurate reproduction of important attributes in the image. Ink is distributed through the bandpass pyramidprimarily according to a user defined importance function. This technique has three main characteristics. First, our technique can produce results similar to many other halftoning techniques by allowing a generic importance function to be specified. If the chosen importance function is average intensity we obtain results similar to traditional halftoning. We also show how the importance function can be changed to highlight areas with high variance. Second, in addition to changing the importancefunction, the drawing primitives can also be changed. By using line segments instead of single pixels as drawing primitives we illustrate how edge enhancement can be achieved. Third, this technique allows the user to easily limit the number drawing primitives used This is useful in limited resource rendering. \\ In addition to providing a tailorable halftoning technique our method can easily be adapted to produce two tone non-photorealistic (NPR) images. We illustrate this by showing how sketched effects can be achieved bv aligning the drawing primitives according to different image attributes. } } @InProceedings{Teece98, author = "Daniel Teece", title = "{3D} {P}ainting for {N}on-{P}hotorealistic {R}endering", booktitle = "SIGGRAPH 98: Conference Abstracts and Applications", year = "1998", pages = "248", annote = {The 3D Expressive Painter is an interactive, expressive 3D painting and rendering system intended for us in production of hand-drawn natural-media-style animations. By using some imported scene geometry, created in a general-purpose modeler, the system allows interactive placement of paint strokes in 3D. The user is able to rotate the scene, select a suitable viewing angle, and paint from the desired direction, eith the depth values for stroke positions calculated from the imported scene. High level effects can be applied to objects within the scene (for example, tracing determined "key edges" with pencil strokes of filling surfaces with a solid color). }, } @phdthesis{Raab1998, author = "A. Rabb", title = "{Techniques for Interacting with and Visualization of Geometric Models}", school = "Otto-von-Guericke University of Magdeburg", year = "1998", address = "", month = {}, note = {} } @phdthesis{Teece98b, author = "Daniel Teece", title = "{Three Dimensional Interactive Non-Photorealistic Rendering}", school = "University of Sheffield", year = "1998", address = "England", month = {}, note = {} } @article{Visvalingam:1998:AFS, author = {Mahes Visvalingam and Kurt Dowson}, title = {Algorithms for sketching surfaces}, volume = {22 }, number = {2-3}, journal = {Computers \& Graphics}, year = {1998}, month = {March}, publisher = {Pergamon Press / Elsevier Science}, pages = {269--280}, note = {ISSN 0097-8493}, } @InProceedings{Wong:1998:CGF, author = "Michael T. Wong and Douglas E. Zongker and David H. Salesin", title = "Computer-{G}enerated {F}loral {O}rnament", booktitle = "SIGGRAPH 98 Conference Proceedings", editor = "Michael Cohen", series = "Annual Conference Series", year = "1998", organization = "ACM SIGGRAPH", publisher = "Addison Wesley", month = jul, pages = "423--434", note = "ISBN 0-89791-999-8", keywords = "adaptive clip art, conventionalization, pattern generation, plant development, ornamentation, texture generation", annote = "This paper describes some of the principles of traditional floral ornamental design, and explores ways in which these designs can be created algorithmically. It introduces the idea of 'adaptive clip art,' which encapsulates the rules for creating a specific ornamental pattern. Adaptive clip art can be used to generate patterns that are tailored to fit a particularly shaped region of the plane. If the region is resized or reshaped, the ornament can be automatically re-generated to fill this new area in an appropriate way. Our ornamental patterns are created in two steps: first, the geometry of the pattern is generated as a set of two-dimensional curves and filled boundaries; second, this geometry is rendered in any number of styles. We demonstrate our approach with a variety of floral ornamental designs.", } @article{Balder:OM:1997, author = {Norman I. Balder and Andrew S. Glassner}, title = {3D object modeling}, volume = {18}, number = {3}, journal = {SIGGRAPH 97 Introduction to COmputer Graphics Course Notes}, year = {1997}, month = {August}, editor = {}, pages = {}, note = {}, keywords = {}, annote = {}, } @Article{Claes97, Author = "Johan Claes and Patrick Monsieurs and Frank Van Reeth and Eddy Flerackers", Title = "{Rendering Pen-drawings of 3D scenes on networked processors}", Journal= {WSCG '97 proceedings}, Year = 1997, Volume = {1}, Number = {}, Month = feb, pages = {} } @article{Coutts:1997, author = "Richard Coutts and Donald P. Greenberg", title = "Rendering with streamlines", journal = {Unpublished}, Year = 1997, annote = {We introduce a new technique for creating non-photorealistic images from computer models. The technique uses two dimensional, vectored streamlines to approximate the hatch markings of a traditional artist. The streamlines are calculated in a two-dimensional vector field that is generated by projectiing three-dimensional surface flow onto the image plane. Aray-traced image is used as a tone map to control the density fo the hatching. Anew one-pass streamline algorithim is introduced that approximates both density and direction. The technique is implemented in a fully automatic system that renders free-form three-dimensional objects with varying levels of sketchiness.}, } @article{Curtis:1997, author = "Cassidy J. Curtis and Sean E. Anderson and Joshua E. Seims and Kurt W. Fleischer and David H. Salesin", title = "Computer-Generated Watercolor", journal = {Proceedings of SIGGRAPH 97}, month = "August", pages = "pages 421--430", year = "1997", keywords = "Fluid simulation, glazing, illustration, Kubelka-Munk, non-photorealistic rendering, optical compositing, painting, pigments, watercolor", abstract = "This paper describes the various artistic effects of watercolor and shows how they can be simulated automaticly. Our watercolor model is based on an ordered set of translucent glazes, which are created independently using a shallow-water fluid simulation. We use a Kubelka-Munk compositing model for simulating the optical effect of the superimposed glazes. We demonstrate how computer generated watercolor can be used in three different application: as part of an interactive watercolor paint system, as a method for automatic image watercolorization, and as a mechanism for non-photorealistic rendering of three-dimensional scenes. ", annote = " This paper presents a method for simulating water color painting. The method uses a complex method of modeling fluid flow, and pigment transportation. By doing this they get away with using simple models for the paper and brushes. This paper also presents a method for automatic painting, based on an image by using image differences. ", } @article{Interrante:1997:ISS, author = {Victoria L. Interrante}, title = {Illustrating Surface Shape in Volume Data via Principal Direction-Driven 3D Line Integral Convolution}, journal = {Proceedings of SIGGRAPH 97}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {1997}, month = {August}, editor = {Turner Whitted}, publisher = {Addison Wesley}, pages = {109--116}, note = {ISBN 0-89791-896-7. Held in Los Angeles, California.}, keywords = {visualization, transparent surfaces, shape representation, principal directions, stroke textures, line integral convolution, solid texture, isosurfaces, volume rendering}, annote = {This paper describes how the set of principal directions and principal curvatures can be understood to define a natural "flow" over the surface of an object and, as such, can be used to guide the placement of the lines of a stroke texture that seeks to represent 3D shape in a perceptually intuitive way. The driving application for this work is the visualization of layered isovalue surfaces in volume data, where the particular identity of an individual surface is not generally known a priori and observers will typically wish to view a variety of different level surfaces from the same distribution, superimposed over underlying opaque structures. This paper describes how, by advecting an evenly distributed set of tiny opaque particles, and the empty space between them, via 3D line integral convolution through the vector field defined by the principal directions and principal curvatures of the level surfaces passing through each gridpoint of a 3D volume, it is possible to generate a single scan-converted solid stroke texture that can be used to illustrate the essential shape information of any level surface in the data. By redefining the length of the filter kernel according to the magnitude of the maximum principal curvature of the level surface at each point around which the convolution is applied, one can generate longer strokes over more the highly curved areas, where the directional information is both most stable and most relevant, and at the same time downplay the visual impact of the directional information indicated by the stroke texture in the flatter regions. In a voxel-based approach such as this one, stroke narrowness will be constrained by the resolution of the volume within which the texture is represented. However, by adaptively indexing into multiple pre-computed texture volumes, obtained by advecting particles of increasing sizes, one may selectively widen the strokes at any point by a variable amount, determined at the time of rendering, to reflect shading information or any other function defined over the volume data. }, } @article{Jobard:1997, author = {Bruno Jobard and Wilfrid Lefer}, title = {Creating evenly-spaced streamlines of arbitrary density}, journal = {Proc. of 8th Eurographics Workshop on Visualization in Scientific Computing}, series = {}, year = {1997}, month = {}, editor = {}, publisher = {}, pages = {45--55}, note = {}, keywords = {}, } @article{Litwinowicz:1997:PIA, author = {Peter Litwinowicz}, title = {Processing Images and Video for an Impressionist Effect}, journal = {Proceedings of SIGGRAPH 97}, year = {August 1997}, pages = {407--414}, annote = {This paper describes a technique that transforms ordinary video segments into animations that have a hand-painted look. Our method is the first to exploit temporal coherence in video clips to design an automatic filter with a hand-drawn animation quality, in this case, one that produces an Impressionist effect. Off-the-shelf image processing and rendering techniques are employed, modified and combined in a novel way. This paper proceeds through the process step by step, providing helpful hints for tuning the off-the-shelf parts as well as describing the new techniques and bookkeeping used to glue the parts together. }, } @article{Luebke:1997:VSO, author = {David Luebke and Carl Erikson}, title = {View-Dependent Simplification of Arbitrary Polygonal Environments}, journal = {Proceedings of SIGGRAPH 97}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {1997}, month = {August}, editor = {Turner Whitted}, publisher = {Addison Wesley}, pages = {199--208}, note = {ISBN 0-89791-896-7. Held in Los Angeles, California.}, keywords = {polygonal simplification, level of detail, view dependent rendering}, annote = {Hierarchical dynamic simplification (HDS) is a new approach to the problem of simplifying arbitrary polygonal environments. HDS operates dynamically, retessellating the scene continuously as the user's viewing position shifts, and adaptively, processing the entire database without first decomposing the environment into individual objects. The resulting system allows real-time display of very complex polygonal CAD models consisting of thousands of parts and hundreds of thousands of polygons. HDS supports various preprocessing algorithms and various run-time criteria, providing a general framework for dynamic view-dependent simplification. Briefly, HDS works by clustering vertices together in a hiera rchical fashion. The simplification process continuously queries this hierarchy to generate a scene containing only those polygons that are important from the current viewpoint. When the volume of space associated with a vertex cluster occupies less than a user-specified amount of the screen, all vertices within that cluster are collapsed together and degenerate polygons filtered out. HDS maintains an active list of visible polygons for rendering. Since frame-to-frame movements typically involve small changes in viewpoint, and therefore modify the active list by only a few polygons, the method takes advantage of temporal coherence for greater speed. }, } @article{Markosian:1997:RNR, author = {Lee Markosian and Michael A. Kowalski and Samuel J. Trychin and Lubomir D. Bourdev and Daniel Goldstein and John F. Hughes}, title = {Real-Time Nonphotorealistic Rendering}, journal = {Proceedings of SIGGRAPH 97}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {August 1997}, editor = {Turner Whitted}, publisher = {Addison Wesley}, pages = {415--420}, note = {ISBN 0-89791-896-7. Held in Los Angeles, California.}, keywords = {non-photorealistic rendering}, annote = {Nonphotorealistic rendering (NPR) can help make comprehensible but simple pictures of complicated objects by employing an economy of line. But current nonphotorealistic rendering is primarily a batch process. This paper presents a real-time nonphotorealistic renderer that deliberately trades accuracy and detail for speed. Our renderer uses a method for determining visible lines and surfaces which is a modification of Appel's hidden-line algorithm, with improvements which are based on the topology of singular maps of a surface into the plane. The method we describe for determining visibility has the potential to be used in any NPR system that requires a description of visible lines or surfaces in the scene. The major contribution of this paper is thus to describe a tool which can significantly improve the performance of these systems. We demonstrate the system with several nonphotorealistic rendering styles, all of which operate on complex models at interactive frame rates. }, } @InProceedings{Masuch:1997:DDA, author = {Maic Masuch and Stefan Schlechtweg and Bert Sch{\"o}nw{\"a}lder}, title = {daLi! -- {D}rawing {A}nimated {L}ines!}, booktitle = {Simulation und Animation '97}, editor = {O. Deussen and P. Lorenz}, year = {1997}, publisher = {SCS Europe}, address = {Erlangen, Ghent}, pages = {87--96}, annote = {We present an animation system for the creation of non-photorealistic 3D animations. Our system daLi! is able to render images using a common 3D model as input. This model may be enriched with additional information concerning for instance hierarchy, structure and presentation style. The rendering is done analytically, which means the output is resolution independent. It results in a series of images that depict the animation using line-drawings. The implementation of daLi! was completely done in Smalltalk. }, } @article{Salisbury:1997:OTF, author = {Michael P. Salisbury and Michael T. Wong and John F. Hughes and David H. Salesin}, title = {Orientable Textures for Image-Based Pen-and-Ink Illustration}, journal = {Proceedings of SIGGRAPH 97}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {August 1997}, editor = {Turner Whitted}, publisher = {Addison Wesley}, pages = {401--406}, note = {ISBN 0-89791-896-7. Held in Los Angeles, California.}, keywords = {Controlled-density hatching, direction field, image-based rendering, non-photorealistic rendering, scale-dependent rendering, stroke textures}, annote = {We present an interactive system for creating pen-and-ink-style line drawings from greyscale images in which the strokes of the rendered illustration follow the features of the original image. The user, via new interaction techniques for editing a direction field, specifies an orientation for each region of the image; the computer draws oriented strokes, based on a user-specified set of example strokes, that achieve the same tone as the image via a new algorithm that compares an adaptively-blurred version of the current illustration to the target tone image. By aligning the direction field with surface orientations of the objects in the image, the user can create textures that appear attached to those objects instead of merely conveying their darkness. The result is a more compelling pen-and-ink illustration than was previously possible from 2D reference imagery. }, } @article{Schlechtweg:1997, author = {Stefan Schlechtweg}, title = {Lines and How to Draw Them}, volume = {}, number = {}, journal = {Norsk samarbeid inner grafisk databehandling}, year = {February 1997}, pages = {4--6}, annote = {The drawing of lines on the computer has been an area of interest for several years. In the beginning, there were more practical reasons behind the development of line drawing algorithms (as for instance the rasterization of lines by BRESENHAM), later more esthetic reasons came into play. This article gives an overview of techniques for drawing lines with certain effects. A line in this context is not necessarily a straight line but can be every kind of curve. The presented methods are only three examples of this interesting area: a simulation of real brush-strokes, a vector-oriented technique for 2D-drawings and a method which can be applied to the output of an analytical renderer to create illustrative effects in line drawings. }, } @Unpublished{Smith97, author = "Alvy Ray Smith", title = "Digital {P}aint {S}ystems {H}istorical {O}verview", note = "Microsoft Corporation", month = may, year = "1997", annote = {This documentation is prepared in responce to the solicitation of information on Digital Paint Systems by the Subcommittee on May 2, 1997. The period I will cover is from the late 1960's to the early 1980s, from the beginings of the technology of digital painting up to the first consumer products that implemented it. I include a little information about major developments in the later 1980s. Two surveys that cover this later period fairly well-when the emergence fo the perrsonal computer completly changed the software universe--were both published in the magizine Computer Graphics World [Smith82a, Robertson88]. My emphasis, of course, is on those systems I knew firsthand. I begin with a simple timeline of programs and systems. I will attempt a weghting and a "genealogy" of these in a later section, where I will also narrow the field to those painting systems that have directly affected the movie industry.}, } @InProceedings{walt97, author = "Bruce Walter and Gun Alppay and Eric P. F. Lafortune and Sebastian Fernandez and Donald P. Greenberg", title = "Fitting {V}irtual {L}ights For {N}on-{D}iffuse {W}alkthroughs" , booktitle = "SIGGRAPH 97 Conference Proceedings", year = "1997", month = aug, pages = {45-48} } @article{zhu_algo, Author ={Ciyou Zhu and Richard H. Byrd and Peihuang Lu and Jorge Nocedal }, Title ={Algorithm 778: L-BFGS-B: Fortran subroutines for large-scale bound-constained optimization}, journal = {ACM Trans. Math. Software}, volume = {23}, number = {4}, Address ={}, pages = {550--560}, Year ={1997} } @article{Tanaka:1997:PIE, author = {T. Tanaka and N. Ohnishi}, title = {Painting-like Image Emphasis based on Human Vision Svstems}, volume = {16}, number = {3}, journal = {Computer Graphics Forum}, year = {August 1997}, pages = {253--260}, keywords = {image emphasis, display technique, visual processing, painting simulation, dynamic range compression}, abstract = {Regional image emphasis is often evident in paintings and illustrations. This technique increases local contrast while reducing global contrast by amplifying image intensity on shadowed surfaces, reducing intensity on illuminated surfaces, and then expanding contrast at intensity edges. The effects are assumed to result from the visual processing needed to interpolate the real world onto canvas. Therefore, we propose an intensity emphasis method based on human vision. This method simulates the adaptation of photoreceptor cells and the lateral inhibition of receptive fields. These attributes of a vision system are realized by computation of relative intensity and differential intensity in small areas. The proposed method can successfully generate painting-like artifacts, which greatly improves the perception of visual elements displayed in an image. Since the method efficiently reduces the dynamic range of images, it can be used for displaying highlighted images on standard graphic monitors. Experiments on a computer-generated image and a photograph confirm the advantages of our method. Proceedings of Eurographics '97. } } @InProceedings{Treavett, author = "S. M. F. Treavett and M. Chen", title = "Statistical {T}echniques for the {A}utomated {S}ynthesis of {N}on-{P}hotorealistic {I}mages", booktitle = "Proc. 15th Eurographics UK Conference", month = mar, year = "1997", annote = {In the field of computer graphics there is an increasing demand for non-photorealistic effects. Techniques have been developed to this end but most involve substantial runtime interaction form the user. This paper presents a new approach that uses statistical techniques to automaticly and reproducibly generate non-photorealistic images. This automatic system could have far ranging uses, including frame by frame conversion of video to produce special effects. Information from the source image is obtained using statistical analysis techniques. Statistical simulations are used to control the placement of effects in the final image. The paper includes a number of example images produced by the system.}, } @book{tuft97, author = "Edward Tufte", title = "Visual explanations", publisher = "Graphics Press", city = "Cheshire, CT", year = {1997} } @article{Wood:1997:MPF, author = {Daniel N. Wood and Adam Finkelstein and John F. Hughes and Craig E. Thayer and David H. Salesin}, title = {Multiperspective Panoramas for Cel Animation}, journal = {Proceedings of SIGGRAPH 97}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {August 1997}, editor = {Turner Whitted}, publisher = {Addison Wesley}, pages = {243--250}, note = {ISBN 0-89791-896-7. Held in Los Angeles, California.}, keywords = {CGI production, compositing, illustration, image-based rendering, mosaics, multiplaning, non-photorealistic rendering}, annote = {We describe a new approach for simulating apparent camera motion through a 3D environment. The approach is motivated by a traditional technique used in 2D cel animation, in which a single background image, which we call a multiperspective panorama,is used to incorporate multiple views of a 3D environment as seen from along a given camera path. When viewed through a small moving window, the panorama produces the illusion of 3D motion. In this paper, we explore how such panoramas can be designed by computer, and we examine their application to cel animation in particular. Multiperspective panoramas should also be useful for any application in which predefined camera moves are applied to 3D scenes, including virtual reality fly-throughs, computer games, and architectural walk-throughs. }, } @InProceedings{zhang97, author = {H. Zhang and K. Hoff III}, month = {April}, year = 1997, title = {Fast Backface Culling Using Normal Masks}, booktitle = {Proc. 1997 Symposium on Interactive 3D Graphics}, pages = {103--106} } @article{Buchanan:1996:SEW, author = {John W. Buchanan}, title = {Special Effects with Half-toning}, volume = {15}, number = {3}, journal = {Computer Graphics Forum}, year = {August 1996}, editor = {Jarek Rossignac and Fran{\c{c}}ois X. Sillion}, publisher = {Blackwell Publishers}, pages = {97--108}, note = {ISSN 1067-7055}, keywords = {Half-toning, non-photorealistic rendering, graphic design}, annote = {Half-toning is the process by which gray-scale images are approximated with sets of black and white pixels. The process works because our eyes perceive a local average, thus half-toning seeks to approximate the local average. Ideally this approximation should be accomplished without introducing "undesirable" artifacts. In many situations the stylized display of images is desired. Often this stylized display is accomplished by the addition of semi-structured artifacts. In current applications the designer processes the image using tools provided by some image processing package. The resulting image is then half-toned and printed. Half-toning these processed images can reduce the visual impact of the special effects that have been introduced in the image. In this paper we show that the processes of controlled artifact introduction and half-toning can successfully be combined. By combining these two processes we ensure that the printed image is what the designer intended. We present a brief overview of the current error-diffusion half-toning techniques. We then propose several ways in which artifacts can be introduced to the image. This discussion is accompanied by a set of illustrative images. In particular, we discuss the introduction of false edges and the alteration of the scan pattern. We illustrate these techniques with a variety of images. We conclude the paper with a discussion on these new half-ioning methods for the generation of binary gray-scale textures. In addition to showing how to generate these binary gray-scale textures we also show how these gray-scale textures can be used to half-tone images. Proceedings of Eurographics '96. }, } @InProceedings{chi96*35, author = "Jutta Schumann and Thomas Strothotte and Andreas Raab and Stetan Laser", title = "Assessing the Effect of {NonPhoto-realistic} Rendered Images in {CAD}", pages = "35--41", ISBN = "0-201-94687-4", editor = "Michael J. Tauber and Victoria Bellotti and Robin Jeffries and Jock D. Mackinlay and Jakob Nielsen", booktitle = "Proceedings of the Conference on Human Factors in Computing Systems : Commun Ground", month = apr # "~13--18", publisher = "ACM Press", address = "New York", year = "1996", annote = {Recent work in computer graphics has resulted in new techniques for rendering so-called non-photorealistic images. While such features are now already appearing in commercially available software, little is known about the effect of non-photorealistic images on users and their usefulness in specific contexts. In this paper we report on an empirical study with 54 architects who compared the output of a sketch-renderer for producing pencil-like drawings with standard output of CAD systems for architectural designs. The results show that the different kinds of renditions actually have a very different effect on viewers and that non-photorealistic images actually do deserve their place in the repertoire of CAD systems. }, } @phdthesis{ Decaudin:1996:thesis, author = "Phillippe Decaudin", title = "{Modeling using Fusion of 3D Shapes for Computer Graphics -- Cartoon-Looking Rendering of 3D Scenes}", school = "Universite de Technologie de Compiegne", year = "1996", address = "France", month = {dec}, note = {} } @TechReport{ Decaudin:1996:CLR, author = "Phillippe Decaudin", title = "Cartoon-Looking Rendering of 3D-Scenes", year = "1996", month = jun, number = "INRIA 2919", institution = "Universite de Technologie de Compiegne", address ="France", abstract = "Cartoon-looking rendering of 3D scenes. This rendering technique produces images having the appearance of a traditional cartoon from a 3D description of the scene (a static or an animated scene). The 3D scene is rendered with techniques allowing to: - outline the profiles and edges of objects in back, - color uniformly the patches, - render shadows (self-shadows and projected-shadows) due to light sources. ", } @phdthesis{elen96, author = "Elena Driskill", title = {Towards the Design, Analysis, and Illustration of Assemblies}, school = "University of Utah", year = "1996", address = "Department of Computer Science, Salt Lake City, Utah", month = sep, abstract = {This document presents an integrate approach for helping designers to specify, revise, analyze, and illustrate assemblies of mechanical parts within the context of a common data structure and set of assembly features. An implementation to test the validity of these ideas has been integrated into an existing spline-based geometric modeling system. There were several distinct facets to this research effort. Methodology for assembly planning was explored to allow a user to lay out the assembly in a diagrammatic form, before creating any geometry. A rough design, laid out initially, can gradually be refined, and the individual components can be designed and edited later using spline-based geometric modeling operations. Research into assembly specification examined how best to allow the user to describe the way parts are actually connected together to form subassemblies, and eventually the final product. Also considered were questions of part interference and part removablility in order to help the user evaluate the utility and manufacturability of the design. Finally, exploded view illustration was explored, with a view toward enabling the user to create clear and informative exploded views of the assembly with minimal intervention. Throughout, information obtained in earlier stages of design was useful in helping to automate later design steps. During the course of this project the author developed a representation of assembly convenient for handling multiple assembly-related tasks, addressed the special problems of interactive assembly design by introduction new constructs for specifying assembly information, explored the usefulness of interactive interference detection techniques, and considered artistic issues, such as good ways to arrange exploded parts in an illustration, as part of creating a practical application.} } @article{Hoppe:1996:PM, author = {Hugues Hoppe}, title = {Progressive Meshes}, journal = {Proceedings of SIGGRAPH 96}, series = {Computer Graphics Proceedings, Annual Conference Series}, year = {1996}, month = {August}, editor = {Holly Rushmeier}, publisher = {Addison Wesley}, pages = {99--108}, note = {ISBN 0-201-94800-1. Held in New Orleans, Louisiana.}, annote = {Highly detailed geometric models are rapidly becoming commonplace in computer graphics. These models, often represented as complex triangle meshes, challenge rendering performance, transmission bandwidth, and storage capacities. This paper introduces the progressive mesh (PM) representation, a new scheme for storing and transmitting arbitrary triangle meshes. This efficient, lossless, continuous-resolution representation addresses several practical problems in graphics: smooth geomorphing of level-of-detail approximations, progressive transmission, mesh compression, and selective refinement. In addition, we present a new mesh simplification procedure for constructing a PM representation from an arbitrary mesh. The goal of this optimization procedure is to preserve not just the geometry of the original mesh, but more importantly its overall appearance as defined by its discrete and scalar appearance attributes such as material identifiers, color values, normals, and texture coordinates. We demonstrate construction of the PM representation and its applications using several practical models. }, } @article{Interrante:1996:ITS, author = {Victoria Interrante and Henry Fuchs and Stephen Pizer}, title = {Illustrating Transparent Surfaces with Curvature-Directed Strokes }, journal = {IEEE Visualization '96}, year = {1996}, month = {October}, editor = {Roni Yagel and Gregory M. Nielson}, publisher = {IEEE}, pages = {211--218}, note = {ISBN 0-89791-864-9}, } @Article{Lebaredian96, Author = "Rev Lebaredian", Title = "{Traditional Cel Animation Look with 3D Renderers}", Journal= {Siggraph 96 Visual Proceedings, ACM SIGGRAPH, ACM Press}, Year = 1996, annote = {This sketch shows a combination of rendering and image processing techniques that produce a cel animation look. All of the following work was completely developed by me with the exception of the trick edge detection and line masking methods which I further developed from the work of Guy Williams who is also affiliated with Warner Brothers Digital Studio. }, } @article{Meier:1996:PRF,