A detailed description - The back-faces of MeshParts composed of a single face that have the DoubleSided property set to true are darker than the front face. Both the back and front faces should be lit properly depending on their orientation to the sun and any other lights.
Where it happens - Both studio and in-game. Also happens with every graphics mode and technology.
When it happens - I first noticed it October 17th 2021 at 8:30 PM AST.
Videos and images -
This is a plane, its colour is medium stone gray, this face (which is the back face) is facing the sun (which you can tell by its shadow).
This is the same mesh part, however this time its front face is visible. You can see its front face is significantly lighter than the back face.
And for a side-by-side comparison (F is front, B is back), keep in mind these are the exact same colour:
Reproduction instructions -
1- Create a single-sided mesh such as a plane in Blender or some like software and upload it to your place
2- Set the MeshPart’s DoubleSided property to true. You should now see that one side is significantly darker than the other.
Reproduction files -
plane.rbxl (39.1 KB)
System information
I’ve tried this on two computers:
AMD Ryzen 5 5600G with Radeon Graphics, 16GB, NVIDIA GeForce RTX 3070 Ti
