Comments on: Lightcuts: directional lights

By: Lightcuts: oriented lights at UncleZeiv’s Corner

Lightcuts: oriented lights at UncleZeiv’s Corner — Wed, 25 Jun 2008 01:31:49 +0000

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By: UncleZeiv

UncleZeiv — Sun, 22 Jun 2008 00:00:43 +0000

Thanks anon for your comments and tests. As for banding: I don’t think it depends on the number of lights, because if you take the time to render them through the usual path, it looks better. It seems to be an error on my side, I am looking into it, stay tuned.

Regarding the “strong sunlight”: yes, shadows are single sampled, thus the ugly lack of antialiasing. This works when a large number of faint lights cast shadows together, it works less if you have a “strong sun”. I am thinking about adding a special case for that, or I could transform a “strong sun” in a small collection of nearby “fainter suns”… Anyway I’m aware of the problem and I will cope with it in some way.

Thanks again for your tests!

By: anon

anon — Sat, 21 Jun 2008 15:48:14 +0000

The link got removed in the previous post

http://img2.freeimagehosting.net/uploads/1e7fcd08ae.png

By: anon

anon — Sat, 21 Jun 2008 15:38:08 +0000

Here is a simple test with a strong sunlight and 8k+ pointlights for ambiant lighting. The strong sunlight makes the render a lot faster
But there seems to be antialiasing problems with the shadows.

By: anon

anon — Sat, 21 Jun 2008 12:12:54 +0000

i just made some tests, and one way to improve the results is to randomise a little the lamp locations

By: anon

anon — Fri, 20 Jun 2008 22:40:50 +0000

Lightcuts are looking awesome, the results are already really interesting However there are some noticable banding on your pictures. I guess you need to add even more lights -> if you want to sample a sphere every 1 degree² you need about 64800 samples. With your sample rate it’s about 1 sample for 2.57 degree².

Because the shadows used are sharp, there will be banding even if the envmap is continuous. However if the envmap is irregular, it could give better results compared to other methods.

I wonder if it’s possible to do some sort of softshadowing.