/// <summary>
        /// Creates a new quad tree node.
        /// This function is iterative, unless the node is a leaf.
        /// </summary>
        /// <param name="bounds"></param>
        /// <param name="parentID"></param>
        /// <param name="id"></param>
        /// <param name="nextAvailableBlockIndex"></param>
        private void CreateQuadTreeNode(BoundingBox bounds, uint parentID, uint id, ref uint nextAvailableBlockIndex)
        {
            //If we have a zero size, we overflowed, return
            if (bounds.Max.X == bounds.Min.X)
                return;

            TerrainQuadTreeNodeType type;

            //This will be integer, since whole terrain size is POW/2,
            //along with the blocks
            float edgeWidth = bounds.Max.X - bounds.Min.X;
            float halfEdgeWidth = edgeWidth / 2.0f;

            float nodeHeight = bounds.Max.Y - bounds.Min.Y;

            float blockWidth = (float)this.SideLength / (float)this.NumBlocksInternal;

            if (edgeWidth == blockWidth)
            {
                type = TerrainQuadTreeNodeType.LEAF;

                this.QuadTreeNodeListInternal[id].BoundsInternal = bounds;
                this.QuadTreeNodeListInternal[id].ParentIDInternal = parentID;
                this.QuadTreeNodeListInternal[id].IDInternal = id;
                this.QuadTreeNodeListInternal[id].TypeInternal = type;
        
                //now we know this is a leaf, and needs to be associated with a block
                //Use the next avilable block slot and add a terrain block using
                //the bounds dimensions. The block index buffers themselves
                //have been created, we just need to fill them with vertices.
                this.QuadTreeNodeListInternal[id].blockIndexInternal = this.NumLeavesAddedInternal;
                this.NumLeavesAddedInternal++;

                this.BlocksInternal[nextAvailableBlockIndex].FillBlock(bounds, this.NumBlocksInternal);

                //advanced the block index for the next call of this method
                nextAvailableBlockIndex++;

                return;
            }
            else
            {
                type = TerrainQuadTreeNodeType.NODE;

                this.QuadTreeNodeListInternal[id].BoundsInternal = bounds;

                this.QuadTreeNodeListInternal[id].ParentIDInternal = parentID;
                this.QuadTreeNodeListInternal[id].IDInternal = id;
                this.QuadTreeNodeListInternal[id].TypeInternal = type;

                //child 0 bounds
                Vector3 boundMax = bounds.Min + new Vector3(halfEdgeWidth, nodeHeight, halfEdgeWidth);
                BoundingBox child0Bounds = new BoundingBox(bounds.Min, boundMax);
                
                this.CurrentTreeNodeIDInternal++;

                this.QuadTreeNodeListInternal[id].ChildInternal[0] = this.CurrentTreeNodeIDInternal;

                this.CreateQuadTreeNode(child0Bounds, id, this.CurrentTreeNodeIDInternal, ref nextAvailableBlockIndex);

                Vector3 boundMin = bounds.Min + new Vector3(halfEdgeWidth, 0, 0);
                boundMax = boundMin + new Vector3(halfEdgeWidth, nodeHeight, halfEdgeWidth);
                BoundingBox child1Bounds = new BoundingBox(boundMin, boundMax);

                this.CurrentTreeNodeIDInternal++;

                this.QuadTreeNodeListInternal[id].ChildInternal[1] = this.CurrentTreeNodeIDInternal;

                this.CreateQuadTreeNode(child1Bounds, id, this.CurrentTreeNodeIDInternal, ref nextAvailableBlockIndex);

                boundMin = bounds.Min + new Vector3(0, 0, halfEdgeWidth);
                boundMax = boundMin + new Vector3(halfEdgeWidth, nodeHeight, halfEdgeWidth);
                BoundingBox child2Bounds = new BoundingBox(boundMin, boundMax);

                this.CurrentTreeNodeIDInternal++;

                this.QuadTreeNodeListInternal[id].ChildInternal[2] = this.CurrentTreeNodeIDInternal;

                this.CreateQuadTreeNode(child2Bounds, id, this.CurrentTreeNodeIDInternal, ref nextAvailableBlockIndex);

                boundMin = bounds.Min + new Vector3(halfEdgeWidth, 0, halfEdgeWidth);
                boundMax = boundMin + new Vector3(halfEdgeWidth, nodeHeight, halfEdgeWidth);
                BoundingBox child3Bounds = new BoundingBox(boundMin, boundMax);

                this.CurrentTreeNodeIDInternal++;

                this.QuadTreeNodeListInternal[id].ChildInternal[3] = this.CurrentTreeNodeIDInternal;

                this.CreateQuadTreeNode(child3Bounds, id, this.CurrentTreeNodeIDInternal, ref nextAvailableBlockIndex);
            }

            return;
        }