What is wrong with my UVs?

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1

I have created a cube from 6 planes, when I set their texture the sides are all stretched… The green lines are my normals.

9241-cuboid.jpg
9241-cuboid.jpg1003×606 99.9 KB

How have you set the UVs? You have made this cube from 36 vertices right?

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each one of those green lines is on a vertice... I just need to figure out how to paint the texture onto the side, as its a separate object. As I am building/triangulating the plain proceduraly, Do I need to rotate my transform before assigning my vertice/triangles to it?

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As long as your UVs are linearly interpolated between 0 and 1 as you move from side to side, you should be good. Have any code where you do that?

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Here is where I build my UVs, is it something in here that is defining how they display? for (int side = 0; side < CubeSides.Count; side++) { for (int j = 0; j < filter1.mesh.vertices.Length; j++) { filter1 = CubeSides[side].gameObject.GetComponent<MeshFilter>(); sideNormals[side].Add(filter1.mesh.vertices[j]); uvs.Add (new Vector2( filter1.mesh.vertices[j].x filter1.mesh.vertices[j].z } filter1.mesh.uv = uvs.ToArray();}

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I presume you are going to deform this mesh otherwise it's a lot of vertices and triangles you don't need...

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2 Answers

2
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The uv values should be in the range 0…1: in a face, the lower left corner has uv = 0,0 and the top right corner has uv = 1,1

If you’re using the standard Unity plane primitive, its vertex coordinates range from -5,0,-5 to 5,0,5 - you should thus divide the x or z coordinate of each vertex by 10 and add 0.5 to shift the result to the range 0…1:

             uvs.Add (new Vector2(
                  filter1.mesh.vertices[j].x/10+0.5f;
                  filter1.mesh.vertices[j].z/10+0.5f;
             }

But your code can be a lot faster if you use fixed arrays and avoid redundant operations inside the loop - like this:

for (int side = 0; side < CubeSides.Count; side++) {
    filter1 = CubeSides[side].gameObject.GetComponent<MeshFilter>();
    Mesh mesh = filter1.mesh;
    int nVerts = mesh.vertices.Length;
    Vector3[] normals = new Vector3[nVerts];
    Vector2[] uvs = new Vector2[nVerts];
    for (int j = 0; j < nVerts; j++){
        normals[j] = Vector3.up;
        Vector3 vertx = mesh.vertices[j];
        uvs[j] = new Vector2(vertx.x/10+0.5f, vertex.z/10+0.5f);
    }
    mesh.normals = normals;
    mesh.uv = uvs;
}

I will also be shortcutting my property calls after I get everything functioning ;)

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3

I figured it out, I just needed to actually think about what I was trying to achieve.

Here is the working code:

                int sideVerts = filter1.mesh.vertices.Length;
    			for (int j = 0; j < sideVerts; j++) {
    				Vector3 vert = filter1.mesh.vertices[j];
    				sideNormals[side].Add(vert);
    				uvs.Add (new Vector2(
    					(1/(units+1))*(j%(units+1)),
    					(1/(units+1))*(Mathf.Floor(j/(units+1))))); 
    			}

Glad to hear you got it working. One thing to note in your code above, however: Every time you access mesh.vertices (or mesh.triangles, mesh.normals, mesh.uvs, etc.) you are getting a copy of the array, not a reference. So in your code above, you'll get a complete array copy of the vertices in every cycle through the for loop. For efficiency, best to get a copy initially, then use it in your for loop. Vector3[] vertices = filter1.mesh.vertices; for(int j=0; j<sideVerts; j++) { Vector3 vert = vertices[j]; ...

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Excellent point, much appreciated :)

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