internal PlanarTerrainBlock(PlanarTerrain terrain, Vector2i blockIndex)
{
this.terrain = terrain;
this.blockIndex = blockIndex;
int size = terrain.BlockSize;
//heightTexture = new Texture2D(device, size, size, true, Format.Single, DepthFormat.None, 0, RenderTargetUsage.PlatformContents);
//heightBackBuffer = new Texture2D(device, size, size, true, Format.Single, DepthFormat.None, 0, RenderTargetUsage.PlatformContents);
treeRoot = new TerrainTreeNode(this, new Vector2i(0, 0), size, terrain.DeepestLod);
DirtyTreeArea = new Box2i(0, 0, size, size);
}