Environment test II

I've added some more detail to my exterior test scene, here are the results. The scene is lit by seven 1024 x 1024 light maps.

The lightmap shown covers the street and building geometry.

1st pass direct light, 464 subsurface samples and 464 final gather samples (52 seconds)

2nd pass 464 fg samples (23 seconds)

3rd pass 4454 fg samples (3 minutes 34 seconds)

1st pass direct light and 464 final gather samples (35 seconds)

2nd pass 464 fg samples (22 seconds)

3rd pass 4454 fg samples (3 minutes 30 seconds)

Gammarggh!

Whilst I'm handling gamma correctly inside the light tool I hadn't actually looked into how 3DS Max handles gamma in it's material colors. It turns out I was gamma correcting material color output from 3DS Max when in fact I didn't need to. The effect was subtle on regular surfaces but became a lot more pronounced on objects with SSS enabled. All this of course is just an excuse to post more images and a link to this excellent article on gamma correction.

Subsurface scattering

I thought I'd see if the technique I'm using to calculate GI could be used to create subsurface scattering type effects as well. I haven't really read up on SSS techniques so this is just an approximation of the actual effect but I have to say I'm quite pleased with the results. It turned out to be fairly straightforward to implement and it's really fast. The 1024x1024 light maps in these scenes were generated in about 40 seconds.