System Information
Operating system: windows 10
Graphics card: Gtx 970
Driver version: 456.71
Blender Version
Broken: (2.83, 2,9, 2.92)
Short description of error
any normal backing process with Selected to active option and with smooth shaded selected mesh makes a pixilize/grid artifacts
Exact steps for others to reproduce the error
Please share that .blend file.
(If multiple devs are looking at this, this just saves a lot of time and also ensures we are all on the same page...)
I'll have to take another look, but based on the video this looks like either the resolution of the normal map is too low and/or you're seeing the pixelation of the low res studio light HDRI.
Increasing the resolution of the bake and environment texture eliminates the pixelation on my system. The normal map was baked at a resolution of 4k as 32-bit float and the HDRI used in my test was this one.
I don't think this is a bug as I can reproduce this initial conditions and my suggestion does appear to fix the problem. Please double check that you're loading the correct texture in the material and the nodes for the world. If you're testing in Material Preview you have to check Viewport Shading > Lighting > Scene World to use the world shader as defined by your nodes.
so it seem like blender can bake only 4k normal map now or not? Why any other software bake that objects correct with 1024 pix resolution?
Another one example, clean bake with 1024 pix normal map size but highpoly not smoothed
If you zoom close enough so that you can see the individual pixel of the normal map, there will be some form of visual degradation in every software.
You could optimize your normal map quite a bit to get more out of the texture resolution. Since the cube is perfectly symmetrical you could create a UV map where all faces are stacked over each other. The baked normal map would then only contain one face with the full 1k resolution.
I haven't seen your last comment while writing mine. If the flat surface of a cube face is not smoothed you get perfectly straight normals, that are consistent across the entire flat surface. It's expected that you don't see any pixelation in this case, because the neighboring pixels mapped to a cube face are exactly the same as they encode the same normal.
