What are normals?

Hello, all. I’m new to mesh modification through scripting, and I was trying to make a simple two tri four vertice square for a bullet hole. However, the shader for the bullet hole is the standard transparent diffuse. Whenever I hit a surface that will trigger a bullet mark, it says “Shader Wants normals, but mesh doesn’t have them” As I said, I’m all new to this, so I was just wondering if someone could explain to me what normals are and how to set them to the code below:

var m : Mesh = new Mesh();
var i : float = bmSize/10;
m.vertices = [Vector3(-i, i, 0), Vector3(i, i, 0), Vector3(i, -i, 0), Vector3(-i, -i, 0) ];
m.uv = [Vector2 (0, 0), Vector2 (0, 1), Vector2(1, 0), Vector2 (1, 1)];
m.triangles = [0, 1, 2, 0, 2, 3];[0, 1, 2, 0, 2, 3];

Thanks In Advance! :slight_smile:

You want this function. Also, read this.