Fair enough. What about normal mapping (ie, an RGB image where pixels represent a normal vector at a a given texture coordinate)? This strikes me as an extremely useful feature which is starting to get wide usage.
Ah yes, this is in fact what I am describing. The program is fed a graphic where the difference in greyscale intensities corresponds to the displacement in the z axis of the points of a triangle representing the 3D surface. Multiply the triangle normal by a light vector for each triangle and you get the highlights/shades corresponding to the bumps. I've got this down pat. You need to use DOT3 combine mode to applying this light effects map to the object's existing appearance, but this is where is fails, giving you a very funky but very incorrect result.
Normal mapping is different from this. Rather than a greyscale image that fakes extra height, normal maps provide more information, giving you a normal vector on a per pixel basis. It provides a much more realistic effect than simple bump mapping.
Here's one of the better demonstrations I've found. It has a very low poly model that after mapping looks almost raytraced.
http://www.drone.org/tutorials/normal_maps.html
Mark McKay -- http://www.kitfox.com
=========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
