void TrySubdivide()
 {
     if (children != null)
     {
         return;
     }
     children = new OctreeTexture2DArray[8];
     for (int i = 0; i < children.Length; i++)
     {
         children[i] = new OctreeTexture2DArray();
     }
 }
 void OnTextureListReceived(List <Texture2D> textures)
 {
     octree = new OctreeTexture2DArray();
     octree.InsertTextureArr(textures.ToArray(), 1);
 }