A Party to the World » raytracer

Parallel Ray Tracer

Dan — Sat, 04 Apr 2009 21:54:05 +0000

This afternoon I was able to successfully parallelize the ray tracer I wrote for Graphics II to run on the Alamode cluster at Mines. Using 17 machines, I was able to render a 4,096 x 4,096 pixel image with 25 passes and up to 5 reflections. It took only 1 minute and 20 seconds.

Reflective spheres rendered at high resolution on a small cluster.

Another image rendered on the same cluster

For the benefit of those who are not computer scientists, this is what the input file looks like:
8192 8192 0 0 20 -1 -1 1 2 0 0 0 2 0 3 10 10 0.8 0.2 9 # These next few lines will define a triangle T # With one of the points at (1, 1, 1) 1 1 1 # and the next point here: 0.12321 0.12321 -1 # and the last point here: -1 1 1 # and with this color setting 1 1 1 1 1 1 0 1 0.7 T -1 1 1 -0.12321 0.12321 -1 0.12321 0.12321 -1 1 1 1 1 1 1 0 1 0 T 1 -1 1 0.12321 -0.12321 -1 -1 -1 1 1 1 1 1 1 1 0 1 0 T -1 -1 1 -0.12321 -0.12321 -1 0.12321 -0.12321 -1 1 1 1 1 1 1 0 1 0 T 1 1 1 0.12321 0.12321 -1 1 -1 1 1 0 0 1 0 0 0 1 0 T 1 -1 1 0.12321 -0.12321 -1 0.12321 0.12321 -1 1 0 0 1 0 0 0 1 0 T -1 1 1 -0.12321 0.12321 -1 -1 -1 1 1 1 0 1 1 0 0 1 0 T -1 -1 1 -0.12321 -0.12321 -1 -0.12321 0.12321 -1 1 1 0 1 1 0 0 1 0 S 0 0 0 0.5 1 0 1 1 0 1 0 1 0.3

Raytracer with Anti-aliasing and Reflection

Dan — Wed, 04 Mar 2009 22:28:44 +0000

For Graphics II, we had to implement a raytracer, and then add anti-aliasing and a feature of our choice. I selected mirrored surfaces.

First, anti-aliasing. Here are a few pictures of the same image rendered with a different number of passes to change the smoothness.

Using one pass

Using 5 passes.

Using 50 passes.

And lastly, here’s a scene of several spheres, some of which are reflective.

A set of spheres, some of which are mirror-like.

A reflective sphere next to some triangles.

A mirrored sphere in the center of four other sphere.

More spheres!

Raytracer

Dan — Wed, 18 Feb 2009 01:51:17 +0000

Last semester for Graphics, we each wrote raytracers, and this semester for Graphics II, we’ve been asked to add more advanced features to them.

I had written mine in Ruby for its short development cycle, but raytracers aren’t the most efficient renderers on the planet, and it would take hours to run on a single input on occasion. So, not wanting to deal with that this semester, I rewrote it in C++. Much faster. The most difficult input (same set) now takes about a minute. I finished it up today, and here are some pretty pictures to sate you: