Operating system: Windows 10 Pro
Graphics card: Radeon(TM) RX 460 Graphics
Broken: 2.81 (sub 16), branch: master, commit date: 2019-11-20 14:27, hash: 26bd5ebd42e3, type: Release
Worked: do not know
Short description of error
Wire-frame like artifacts on the baked normal map when using bevel shader node
Exact steps for others to reproduce the error
- Open provided .blend file
- Select the half_sphere object
- In "Render Properties" panel in the "Bake" section press "Bake"
- Replace the normal input of the Principled BSDF node with the newly baked normal map
- Preview the normals on the half_sphere and plane objects
Long description of error
It seems to me that the bevel shader node is affecting the normals across the all shading points on the surface and not just at the place where there is beveling,
which produces easily visible artifacts that follow the mesh wire-frame, especially when using high gloss values.
In the image bellow and in the blend file normal map is shown on a plane to see the issue more easily:
But the issue is visible on the model itself and persists when working with other models and blend files:
Normal map exaggerated with levels in PS for illustration:
Clearly visible artifacts in the places where normals should be flat (pointing up) and shouldn't be affected by the bevel node.
This is why i think (i might be guessing too much) this is the same issue as in https://developer.blender.org/T61916. But the OP never responded to clarify the issue.
As i tried to work around this issue i also found out:
- Artifacts are also visible when baking with low-poly, high-poly and averaged cage setup
- Artifacts are not visible when baking object space normals
Which is really not a viable option since there is no multi-sampling when baking in blender, and we get other kind of artifacts where normals should simply be flat.
Below is object space map rebaked to tangent space map
- When i subtract world normals from geometry node with world normals from bevel node i saw this:
Which at first seems as expected result, but when i added gamma node after the vector math node:
Result above suggest to me (i am just guessing as a layman) that the range of bevel shader node effect on the surface normals is quite wider then it should be. Setup i used is provided in "Collection 2" of the blend file.
So is this a bug, an unavoidable side effect of bevel shader, or it can be improved so this effect is masked and doesn't affect places where normals should remain flat?!