Unity | mesh.colors won't color my custom mesh object

Question

I have build a custom pyramid in Unity like this:

    Mesh mesh = GetComponent<MeshFilter>().mesh;
    mesh.Clear();
    Vector3[] vertices = {
        new Vector3(0.0f, 0.5f, 0.0f),
        new Vector3(0.5f, 0.0f, 0.5f),
        new Vector3(-0.5f, 0.0f, 0.5f),
        new Vector3(-0.5f, 0.0f, -0.5f),
        new Vector3(0.5f, 0.0f, -0.5f),
    };

    int[] triangles = {
        1, 2, 3,
        1, 3, 4,
        1, 0, 2,
        2, 0, 3,
        3, 0, 4,
        4, 0, 1
    };


    mesh.vertices = vertices;
    mesh.triangles = triangles;

I am trying to color my pyramid, as said in unity documentation like this:

    Color[] colors = new Color[vertices.Length];

    for (int i = 0; i < vertices.Length; i++)
        colors[i] = Color.Lerp(Color.red, Color.green, vertices[i].y);

    // assign the array of colors to the Mesh.
    mesh.colors = colors;

but this wont change a thing..

i have no materials on my object, only this script. Any ideas?

Nothing.. Should i use materials to color my pyramid? Sorry, i am 2 days in unity and glga :p — Iraklis Bekiaris, Apr 16 '19 at 17:57
@derHugo I also udnerstand that i may have to use a shader..? I dont know how this works either.. I mean i have an idea about shaders but no how to use them in unity — Iraklis Bekiaris, Apr 16 '19 at 18:01

derHugo · Accepted Answer · 2020-04-27T05:51:01.860

Note that comment in mesh.colors

// (Note that most built-in Shaders don't display vertex colors. Use one that does, such as a Particle Shader, to see vertex colors)

so in order to see those colors in the MeshRenderer component add a material that uses such a Vertex or Particle Shader.

Therefore

in the Project view (Assets) do right click &rightarrow; Create &rightarrow; Material
Give that material a name
For the Shader from the Dropdown menu find and select e.g. Particles &rightarrow; Standard Unlit (or if you want to receive lightning Standard Surface)
Finally use this material for your object either by dragging it into the MeshRenderer &rightarrow; material or by simply dragging it onto the according object in the Scene view (the latter might not work if there is no mesh for that object yet)