I recently created a model in Blender using a Cylindrical mesh, modified it to my liking and after checking the normals to see if there are any inverted faces, I imported it to Roblox Studio in .fbx format. I wanted to use this model as a platform.
Black Spots/ Shadows appears on my model when I use it in roblox Studio. It goes away after I scale the object up/ down to some extent and rotating the object makes the black spots appear in some other locations, making me doubt the lighting.
Since I dont need shadows, I tried turning off CastShadow now and it took away those spots. Though this helps in my scenario of not wanting shadows, the same can’t be said for scenarios where shadows are needed
In Blender Edit mode click A (select all) then go to the Meshes dropdown menu, select Normals, then set Reset Normals (I think that’s what it was going by memory).
When you modify a mesh in Blender it may change the normals of many of the vertices. Resetting the normals will recalculate the direction they should be facing.
You can also have a close look at the way the tris sometimes get figured out.
If you modify a quad and it turns out it has a slightly concave face when the tris are calculated you can rotate the tri edge to make it slightly convex which can help with shading.
I’ve also seen where a ring of quads will calculate to tris and have a couple with the tri edge oriented the opposite diagonal than the rest. This may affect the shading normals at the vertices as well.