Assignment #3
Jonathan Hall

Threaded Ray Tracing and Path Tracing

Cornell Box Repeated 10 times

Threads
 Time
1 (no threads)
 6.511412s
2
 4.148009s
4
 2.217055s
8
 1.281899s
As you can see threading yields approximately linear speed-up.

Explicit Direct Lighting:

Cornell Box
    Lit by a off-white (18.4,15.6,8) light and black (0,0,0) background.  RGB colors.  Gamma correction of 2.0

    Notice that Explicit Direct Lighting converges much faster.  10 samples per pixel of Explicit Direct Lighting is comparable to 1000 samples per pixel of Naive Path Tracing


 Naive Path Tracing
 Explicit Direct Lighting











10 samples/pixel
 Cornell Box Naive Path Traced 10 samples per pixe
*Colors didn't survive jpeg compression
 Cornell Box Explicit Direct Lighting 10 samples per pixel











100 samples/pixel
 Cornell Box Naive Path Traced 100 samples per pixel
 Cornell Box Explicit Direct Lighting 100 samples per pixel











1000 samples/pixel
 Cornell Box Naive Path Traced 1000 samples per pixel


Test Spheres
    The bottom white (1,1,1) is lit by the white (5,5,5) top sphere.  RGB colors
   
    The shadow is noisy because I didn't implement any good sphere random point sampler.

Test Spheres with 1000 samples
1000 samples per pixel