Adds normal information to polygons, giving each vertex of a polygon a normal information. With this, you can archive smoothed edge effects. nbuf holds n*9 float values, 3 (x,y,z) vector values for each vertex of the Polygon. Don't worry if you don't use this, it's kind of hard to calculate and the server will use some always use some proper normal values (same for every vertex, calculated by the plane which is defined by the 3 points of the polygon.