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There are 64k cubes, 64k-1 's materials are assigned to sharedMaterial of first cube. But unity is not batching them together. Only cubes themselves are batched.

  • Static color(but different per cube)
  • Dynamic position and rotation per cube

How can I force unity to batch them all so it sends all cube data with only an array then draw once instead of drawing 64k times?

enter image description here

Each cube has a constructor as:

public class Test : MonoBehaviour {
    public static System.Random r { get; set; }
    // Use this for initialization
    public static Material m=null;
    void Start () {
        if (r == null)
            r = new System.Random();
        sayac++;
        if (m == null)
            m = GetComponent<Renderer>().sharedMaterial;
        else
            GetComponent<Renderer>().material = m;
        GetComponent<Renderer>().material.color = new Color((float)r.NextDouble(), (float)r.NextDouble(), 1);
        var mesh= GetComponent<MeshFilter>().mesh;
        var vertices  = mesh.vertices;
        var colors  = new Color[vertices.Length];
        var i  = 0;
        while (i < vertices.Length)
        {
            colors[i] = new Color((float)r.NextDouble(), (float)r.NextDouble(), (float)r.NextDouble());
            i++;
        }
        mesh.colors = colors;
        mesh.UploadMeshData(false);
        mesh.Optimize();
    }


}

and they are instantiated from a cube as:

    for(int i=0;i<1024*64;i++){
        var pos = new Vector3(i % 64, (i /64) % 64, (i / 4096) % 64);
        pos*=2.5f;
        var cu = Instantiate(ref_cu, pos, Quaternion.identity);
        cu .name = "cube_" + i;
    }

After deleting 'material.color' lines, batching has started. But now cubes are not easily seen as with different colors. I need them different colored but not changing. Static color but different per cube. How it looks now:

enter image description here

its not easy to see individual cubes.

public class Test : MonoBehaviour {
    public static System.Random r { get; set; }
    // Use this for initialization
    public static Material m=null;
    void Start () {
        if (r == null)
            r = new System.Random();
        sayac++;
        if (m == null)
            m = GetComponent<Renderer>().sharedMaterial;
        else
            GetComponent<Renderer>().material = m;

    }


}
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  • 2
    \$\begingroup\$ This line: GetComponent<Renderer>().material.color creates a copy of the material for every instance. \$\endgroup\$ Commented Apr 13, 2016 at 17:33
  • \$\begingroup\$ Updated question, fps increased with batching but I cannot see cubes clearly. Colors will be static per cube and changed only once. \$\endgroup\$ Commented Apr 13, 2016 at 17:40
  • \$\begingroup\$ Looks like your material isn't making use of the vertex colours you've assigned. What shader are you using? \$\endgroup\$ Commented Apr 13, 2016 at 17:41
  • \$\begingroup\$ No shaders, I just deleted whole thing after sharedMaterial line. \$\endgroup\$ Commented Apr 13, 2016 at 17:43
  • \$\begingroup\$ If you haven't assigned a shader in code then it's still using the same as the default material on your ref_cu prefab. Check its MeshRenderer component in the inspector. As an aside, any reason you're constructing a new System.Random instance for every cube instead of having them use Unity's static Random class? \$\endgroup\$ Commented Apr 13, 2016 at 17:46

1 Answer 1

Reset to default
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To answer your original question about why Unity wasn't dynamic batching in this case...

The renderer.material property has a getter that silently creates a unique copy of the material the first time you access it.

This is convenient when you want to change the colour/texture of one instance without that change affecting every other instance in the game. Like this line from your code above:

    //                       ↓ Copy happens when you access .material here
    GetComponent<Renderer>().material.color = new Color(
                         (float)r.NextDouble(),
                         (float)r.NextDouble(), 
                         1);

But once the material has been copied this way, Unity can no longer batch this instance together with other instances using other copies of the material, even if they differ by just a colour parameter.

To avoid copying when accessing a material, you can use renderer.sharedMaterial, but that won't get you unique colours per cube instance.

Your idea of modifying the vertex colours to get unique colours in one batch will work, but you'll need to use a material that reads & displays those vertex colours. This is a different subject from batching, so I recommend posting a new question about rendering vertex colours (or better yet, search to see whether one has already been asked & answered — there's a good chance there's at least one answer to your question already available)

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  • \$\begingroup\$ Ok, I will ask about color later. Also there is transform translate rotate performance penalty per cube which I will ask new question about that too, probably needs a shader instead of doing in cpu. \$\endgroup\$ Commented Apr 13, 2016 at 18:09
  • \$\begingroup\$ Wouldn't using a Material Property Block be a solution? \$\endgroup\$ Commented Apr 14, 2016 at 14:40
  • \$\begingroup\$ @Philipp Excellent question. I haven't found anything in the docs stating that dynamic batches can group Renderers using different MaterialPropertyBlocks in one draw call, and search hits I get, while old, seem to state that these Renderers do not get batched together. I'd love to see updated info on this if you have any. \$\endgroup\$ Commented Apr 14, 2016 at 15:25

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