Mark Kim

Computer Scientist

CS 6620 Ray Tracing: Assignment 4

prog04-nofilter.scn
Setup/load time: 0.000764 seconds
Render time: 0.257 seconds
Post-process time: 0.00621 seconds

prog04-jittered-triangle.scn
Setup/load time: 0.000763 seconds
Render time: 9.03 seconds
Post-process time: 0.00609 seconds

prog04-jittered-gaussian.scn
Setup/load time: 0.000755 seconds
Render time: 2.36 seconds
Post-process time: 0.00615 seconds

prog03-nofilter.scn
Setup/load time: 0.0412 seconds
Render time: 2.95 seconds
Post-process time: 0.00606 seconds

prog03-jittered-triangle.scn
Setup/load time: 0.00164 seconds
Render time: 106 seconds
Post-process time: 0.00643 seconds

prog03-jittered-gaussian.scn
Render time: 26 seconds

####Design Decision####

  1. 2-pixel triangle filter (and Lanczos Filter) is a complete hack. I had a nice system setup with samplers separated from filters, but with the 2-pixel situation, I had to basically had no choice to to put part of the filter code in the sampler portion.</li>
  2. I pre-generate my filters, mostly because of Gaussian filtering.  I just found it easier to create the filters immediately.  I spent some time thinking about it especially when it came to jittered filtering.  For instance, when I pre-generate my Lanczos filter, I use the uniform spacing to pass into my sinc generator.  I could probably call it for every jittered sample and then sum up everything and find the average, but I don’t see the point.  Perhaps it’ll be slightly more jittered.  I’m unsure. </li>
  3. The Gaussian filter is generated using binomial coefficients. Borrowed from Spring 2001 UW graphics class slides.</li>
  4. The Lanczos filter is truncated sinc filter. I’m not sure how well it works: the images look "okay." One of the problems I had was picking a proper kernel size and under-sampling. Well, less under-sampling and more just picking the wrong samples. With kernel size = 3, and a 3x3 filter, I discovered that the vector looked like [0,1,0]. Smooth move on my part. So, I filter across 2 pixels as well.</li>

####Miscellaneous#### Time: 15 hours

Difficulty: Not too bad, I spent more time thinking how I wanted to implement 2-pixel filtering than in the box filter.

####Code####