Hey, I have a sphere which I''m mapping a clould texture to. The sphere is around a planet object and for the most part looks fine. However, from some angles there are artifacts which are a little hard to explain, but look nasty(see www.laeuchli.com/jesse/error.gif). Could someone give me a hint on what I could be doing to be causing this?!?
Using spheres with blending is somewhat tricky. Check out www.nvidia.com''s developer section. Theres a paper about correct (and incorrect) blending. In fact, you probably draw the polygons in the wrong order. When using blending, you must draw polygons further away *before* drawing those nearer. That is, if you stand in front of the window, you have to draw all the things behind the window first, and draw the window afterwards. Note that blending works directly at the graphic boards image buffer, therefore it can change only things which have been drawn already. For the same reason, blending is terribly slow.