Shadow terminator problem
Hi All,
We are using Cycles to produce some renders of lowpoly models and the shadow terminator problem is becoming serious. We need to solve this directly in cycles without using any mesh subdivision in Blender. Is there any way to solve this? Any suggestion?
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(I would like to make a note here : On a technical point of view, this issue has nothing to do with mesh detail. As having more dense mesh only makes the issue less noticable. But it's still there and in some cases of close-up frame it's right in your face)
It is called shadow terminator artefact , most raytracers suffer from it in some form. There's a lot of materials on it on developer.blender.org , I also suggested a patch that you can try.
The reason of this problem: visible curveture (with smoothed normals) do not match real geometry. But ray in Cycles can work only with real geometry. The solution of this problem — making virtual geometry, based on real+normals. And this will be a trick like Pixel depth offset + parallax occlusion.
As I understand it, this isn't actually a bug, its just a result of the rendering algorithm cycles uses. It'd be like calling it a bug that shadows created using shadow mapping are pixelated. From what I've heard, getting rid of terminator artifacts wouldn't be to solve a bug, it would be to implement a new feature.
Edit: This is one of Cycles limitations. I was wrong suggesting it's the geometry.