CS 6620
Project 3

Required Images

Code Listing

My source code for project 3 can be found here.

Creative Images

My creative images are a day and night scene of the coast of Honolulu, Hawaii. The new objects I use are the box, triangle, disk and heightfield. I used terrain data found on the web for the heightfield, a plane for the ocean, boxes and triangles for the boats, and disks for the sun/moon and clouds.

Design Choices

There weren't many new decisions to be made for this project because we were mainly implementing new objects. Below are some of the design decisions I made:

• The disk, ring, and triangle classes are all derived from my primitive class, like the previously defined objects. I followed the notes to implement all of the intersect functions for these objects.
• I decided to implement a scratchpad. I use this to compute the normals for the triangles and heightfields. For triangles, I used normals specified at each vertex. For heightfields, I follow the patch normals algorithm outlined in the notes.
• For the box intersection, I decided to implement the ray-box intersection algorithm in the notes. I decided to use this rather than the one in the paper, because I used the primitive class for all of my objects. In order to implement the more efficient intersection algorithm I would have had to modify the function to take in additional parameters. I thought this would be more trouble than it was worth.
• For the heightfield, I followed the implementation in the notes. I used the bilinear patch intersection, implementing version 3 of the ray-patch intersection algorithm, as recommended in class.
• Scene description:
  • A scene consists of a background, camera, lights, ambient light, objects and an image.
  • The background, camera, lights, ambient light and image are all directly added to the scene.
  • A group is created and the objects are added to this group, which is then added to the scene.
• I also finally included Time.h to keep track of the rendering time.

Extra Credit

For the extra credit, I first downloaded and converted the terrain data for my hometown, Buffalo, NY, but it wasn't very exciting. So instead, I decided to call Honolulu, Hawaii my home for this assignment. It was 1371x1284, with a minimum z value of 0 and a maximum z value of 959. I had to modify the mds file so that the first two numbers correspond to the number of cells not points. I also had to switch the order so it the number of cells in x and y instead of vice versa. In addition, I needed to scale the data. The heightfield can be seen in my creative image above, or alone in the images below.