Part 6: Anisotropic BRDF

I implemented the Ward BRDF. The colbalt-blue sphere in the image has αu=0.01 and αv=0.1. The diffuse component is zeroed. The yellow half-ring surrounding it has αu=0.1 and αv=0.01 and a diffuse component that is approximately half of the specular. Note the vertical blur on the reflection of the light source in the sphere and the horizontally elongated highlight on the torus. I also tested out my bump-mapping code in this scene. I'm quite pleased by how it turned out, particularly in the way the bumps catch the highlights.

This image was rendered at 512x512 with 2560 samples per pixel and with 1/3, 1/3, 1/3 mixture densities. A 4x4 pixel importance-sampled b-spline filter was used for antialiasing and stratification over the pixel area and wavelength was done using a low-discrepency Hammersley sequence. It took about 43 minutes to render using both processors on a dual 2.5GHz G5.

Ward BRDF
Last modified: Fri Jul 22 01:35:10 MDT 2005