Unity UV map, tint / change color of texture

Question

I have an array of vertices with texture coordinates for a UV map in Unity:

newUV.Add(new Vector2 (0, 1)); // FACE 1
newUV.Add(new Vector2 (1, 1));
newUV.Add(new Vector2 (1, 0));
newUV.Add(new Vector2 (0, 0));

newUV.Add(new Vector2 (0, 1)); // FACE 2
newUV.Add(new Vector2 (1, 1));
newUV.Add(new Vector2 (1, 0));
newUV.Add(new Vector2 (0, 0));

mesh.uv = newUV.ToArray();

It textures my mesh just fine.

How could I go around tinting FACE 1 to a darker color? Let's say the texture is just plain green and I wanted to texture only on FACE 1 to be a darker shade of green.

Answer 1

Let's say the texture is just plain green and I wanted to texture only on FACE 1 to be a darker shade of green.

I think you have 3 possibilities:

• use a second texture lookup to drive different light intensity on different part of the mesh. Perhaps you want to look at self-illumin shaders built-in in unity. May be that's exactly what you are looking for, if you only want a different light intensity on some area.

Two other way of doing it (probably not suited for your specific case, but useful in more complex scenarios):

• split the mesh into 2 submesh and assign a different material to each submesh (same texture but different shaders of uniform values) => (draw back: you'll probably have an additional draw call unless the mesh can be static/dynamic batched)

• encode some additional data into some unused vertex attributes and use that data inside the shader to apply a darker shading (draw back: memory overhead per vertex: if the mesh is you will waste memory for just darkening a potentially small area)