The driver almost certainly does convert the quad to triangles, but the calculated average surface normal will be different, because with quads, the point has exactly two contributing normals, which averate to a normal pointing away from the centerline of the cylinder (as desired). However, when the normal smoothing is done on the triangles, one facet will have two triangles contributing to the given point, while the other facet only has one. This will cause the normals on the bottom of the cyllinder to get pulled one way (say clockwise), while the top ones get pulled the opposite way (say counterclockwise). This leads to visible artifacts.
T-Junctions re-visited
« Next Oldest | Next Newest »
Users browsing this thread: 5 Guest(s)