mesh combining.cs

		{
			var batch = batches.First();
			
			var sprite = batch.Key;
			var mat = new Material(batch.First().material);
			mat.mainTexture = sprite.texture;
			
			var count = batch.Count();
			var indexes = new int[6*count];
			var vertexes = new Vector3[4*count];
			var uvs = new Vector2[4*count];
			
			var iidx = 0;
			var vidx = 0;
			foreach(var clump in batch){
				indexes[iidx + 0] = vidx + 0;
				indexes[iidx + 1] = vidx + 1;
				indexes[iidx + 2] = vidx + 2;
				indexes[iidx + 3] = vidx + 1;
				indexes[iidx + 4] = vidx + 2;
				indexes[iidx + 5] = vidx + 3;
				iidx += 6;
				
				var bounds = sprite.bounds;
				var m = clump.transform.localToWorldMatrix;
				vertexes[vidx + 0] = m.MultiplyPoint(new Vector3(bounds.min.x, bounds.min.y, 0)); uvs[vidx + 0] = new Vector2(0, 0);
				vertexes[vidx + 1] = m.MultiplyPoint(new Vector3(bounds.max.x, bounds.min.y, 0)); uvs[vidx + 1] = new Vector2(1, 0);
				vertexes[vidx + 2] = m.MultiplyPoint(new Vector3(bounds.min.x, bounds.max.y, 0)); uvs[vidx + 2] = new Vector2(0, 1);
				vertexes[vidx + 3] = m.MultiplyPoint(new Vector3(bounds.max.x, bounds.max.y, 0)); uvs[vidx + 3] = new Vector2(1, 1);
				vidx += 4;
			}
			
			var mesh = new Mesh();
			mesh.vertices = vertexes;
			mesh.uv = uvs;
			mesh.triangles = indexes;
			
			var go = new GameObject("ClumpMesh");
			var mf = go.AddComponent<MeshFilter>();
			mf.mesh = mesh;
			
			var mr = go.AddComponent<MeshRenderer>();
			mr.sharedMaterial = mat;
		}