UV Mesh only on one Side - how to?

Questions & Answers
1

Hello everybody.

I want to make a 3d Jigsaw Puzzle, for that I generate several jigsaw puzzle parts.
And I have a Image - like in a real jigsaw puzzle. I want to show this image just on the front of the jigsaw puzzle parts.

Whats the best way to do this?

I tried this two approaches:

A) set the UVs of the puzzle part only for the front face. Result is this Error:
Mesh.uv is out of bounds. The supplied array needs to be the same size as the Mesh.vertices array.

B) Generate a plane in code and set the GetComponent().material.mainTextureScale and GetComponent().material.mainTextureOffset. This works for rectangular plane. But not for more complicated “plane-structures”.

Thanks a lot for help

Lukas

2

Solution is to add an empty GameObject and create again the “front mesh” and set the image to it.

Puzzle has an empty GameObject called ImageFrontPlane;
mesh and vertices of the front face are presaved.

public void SetImage(int puzzlePosX, int puzzlePosY, int puzzleSizeX, int puzzleSizeY, Material puzzleImage)
    {
        _imagePlane = gameObject.transform.FindChild("ImageFrontPlane").gameObject;

        MeshFilter meshFilter = _imagePlane.AddComponent<MeshFilter>();
        if (meshFilter == null)
        {
            Debug.LogError("MeshFilter not found!");
            return;
        }
        Mesh imageMesh = meshFilter.mesh;
        imageMesh.Clear();


        imageMesh.vertices = _verticesOfPlane;
        imageMesh.triangles = _trianglesOfPlane;

        imageMesh.RecalculateNormals();
        imageMesh.RecalculateBounds();
        imageMesh.Optimize();

        float scaleX = 1.0f/puzzleSizeX;
        float scaleY = 1.0f/puzzleSizeY;
        float offsetX = scaleX*puzzlePosX;
        float offsetY = scaleY*puzzlePosY;

        ArrayList uvList = new ArrayList();


        foreach (Vector2 point in _pointsOfPlane)
        {
            uvList.Add(new Vector2(offsetX + point.x*scaleX, offsetY + point.y*scaleY));
        }

        imageMesh.uv = (Vector2[]) uvList.ToArray(typeof(Vector2));

        MeshRenderer meshRenderer = _imagePlane.AddComponent<MeshRenderer>();
        if (meshRenderer != null)
        {
            meshRenderer.material = puzzleImage;
        }
    }