public BlockBasedSceneGraph(int numblocks)
 {
     blocks = new SceneGraphBlock[numblocks];
     for (int i = 0; i < numblocks; i++)
     {
         blocks[i] = new SceneGraphBlock(i);
     }
 }
 public BlockBasedSceneGraph(int numblocks)
 {
     blocks = new SceneGraphBlock[numblocks];
     for (int i = 0; i < numblocks; i++) blocks[i] = new SceneGraphBlock(i);
 }