public bool IntersectsTopY(VoxelVector3Int point)
            {
                bool intersecting = false;

                if (point.y > corners.bot_left_front.y && point.y <= corners.top_left_front.y)
                {
                    intersecting = true;
                }
                return(intersecting);
            }
            public bool IntersectsBackZ(VoxelVector3Int point)
            {
                bool intersecting = false;

                if (point.z > corners.bot_left_front.z && point.z <= corners.bot_left_back.z)
                {
                    intersecting = true;
                }
                return(intersecting);
            }
            public bool IntersectsRightX(VoxelVector3Int point)
            {
                bool intersecting = false;

                if (point.x > corners.bot_left_front.x && point.x <= corners.bot_right_front.x)
                {
                    intersecting = true;
                }
                return(intersecting);
            }
        // ---------------------------------------------------------------------------------------------
        //
        // ---------------------------------------------------------------------------------------------
        public static VoxelCorners createVoxelCorners(VoxelVector3Int pos, int width, int height, int depth)
        {
            VoxelCorners vc = new VoxelCorners();

            vc.bot_left_front  = new VoxelVector3Int(pos.x, pos.y, pos.z);
            vc.bot_left_back   = new VoxelVector3Int(pos.x, pos.y, pos.z + depth - 1);
            vc.bot_right_back  = new VoxelVector3Int(pos.x + width - 1, pos.y, pos.z + depth - 1);
            vc.bot_right_front = new VoxelVector3Int(pos.x + width - 1, pos.y, pos.z);
            vc.top_left_front  = new VoxelVector3Int(pos.x, pos.y + height - 1, pos.z);
            vc.top_left_back   = new VoxelVector3Int(pos.x, pos.y + height - 1, pos.z + depth - 1);
            vc.top_right_back  = new VoxelVector3Int(pos.x + width - 1, pos.y + height - 1, pos.z + depth - 1);
            vc.top_right_front = new VoxelVector3Int(pos.x + width - 1, pos.y + height - 1, pos.z);

            return(vc);
        }
            //
            public bool Intersects(VoxelVector3Int point)
            {
                bool intersecting = false;

                if (point.x > corners.bot_left_front.x && point.x < corners.bot_right_front.x)
                {
                    if (point.y > corners.bot_left_front.y && point.y < corners.top_right_front.y)
                    {
                        if (point.z > corners.bot_left_front.z && point.z < corners.bot_left_back.z)
                        {
                            intersecting = true;
                        }
                    }
                }
                return(intersecting);
            }