This appears to be an issue that’s been happening for a long time, but I was surprised to see how little information on it I could find beyond “It’s just how the engine works”
When you set a meshpart to ‘Performance’ render fidelity, the shading on them goes completely bonkers the moment the mesh quality is reduced.
What’s weird about this is, that even at an extremely far distance, ‘Automatic’ quality will never have this effect (Even though presumably Automatic is also using lower-poly lods further away)
This problem makes it very hard to optimize a game as a developer, because we are encouraged to use Automatic or Precise to avoid this issue. I recently upgraded the models of trees in my game, but was disappointed to find the performance of these new trees was worse than the part-based previous ones - All because I can’t put them into ‘Performance’ mode even at great distances due to the extreme artifacting appearing on the performance trees the moment their detail level goes down.
Expected behavior
I expect meshes set to “Performance” RenderFidelity to appear lower-quality at a distance, but not have completely broken shading, as roblox should be able to shade a low-poly model at a distance without causing extreme distortion without trouble.