Direct Lighting for (not so) Naive Path TracingJanuary 8, 2014 - 11:44 pm by Joss Whittle C/C++ Graphics PhD
Finally starting to make up for the time I took off over christmas!
I have successfully added an unbiased direct lighting calculation into the renderer which makes it possible to render more complex scenes with smaller and sparser light sources. Below are two images rendered with direct lighting and a small (
1x1) light source simulating a 3400k bulb. In the top image a white ceramic sphere is shown while in the second image it is replaced by a glass one.
250 Samples: This image was given more time to converge due to the caustics under the glass sphere which converge slower.
Work on Bi-Directional Path Tracing within the renderer is, sadly, going a lot slower. Currently direct shadows and the more subtle ambient occlusion style effects of global illumination are being washed out of the images. I believe the problem lies with how I am weighting together the contributions from all the different generated paths for a given pair of eye & light subpaths.
As you can see below, only the more dramatic effects of ambient occlusion remain around the bases of the two hemi-cubes. All other detail is lost.