Hey guys,
I generated a geometry in Unity and it acts as a wall, but for one of the sides to work correctly, I need to invert the normals.
Somewhere around the internet I was advised to get the normals of the geometry, multiply all of them by -1 and them assign it back to the geometry but this causes no effect whatsoever.
Is there anything I’m missing?
Thank you very much.
What you know as face normals doesn’t exist in 3D engines. “Face normals” aren’t actual vectors. They just define which side is the visible side. On the GPU this is determined by the winding order of your triangles. In Unity a face need to have clockwise winding in order to be visible. So backfaces have a counterclockwise winding order.
So this:
0----2
| /
| /
| /
|/
1
need to be this:
0----1
| /
| /
| /
|/
2
The vertex normals have no influence on the fact which is the front and which is the back side. Vertex normals are only used by the shader to calculate lighting of the face.