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fu5ha / rendy-pbr

PBR rendering example/experiment with rendy
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What's the reason of white flaw in the picture? #1

Open piaoger opened 5 years ago

piaoger commented 5 years ago

Rendy is interesting and this project is very good sample! Thanks. It seems there are some flaws.how to fix?

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fu5ha commented 5 years ago

There's two things going on here:

  1. Specular aliasing. This is symptomized by the discontinuity (disconnected, sparse white dots on sharp highlights), and is caused by essentially undersampling of normals. The most popular way to solve this in a physically based renderer is to use TSAA (time-sampled anti aliasing). This is in the roadmap but so far unimplemented.
  2. A strong light shining onto a complex model without shadow mapping. The rear light is very strong and is not shadow mapped. Since there is no shadow map, the only thing influencing the lighting is the surface normal, light location, and view location. This means that even in places where the light should be blocked by nearer geometry, it still gets lit like normal. This can be fixed by shadow mapping, but since shadow mapping is expensive it is usually is only done for a sun-like light and maybe a couple point lights. This is in the roadmap but so far unimplemented.