I have developed a program which displays the volume texture. The program is in Direct3D 9. I am loading a standard volume texture - a human skull dataset. I wish to add lighting effect to this. I did some google on this, but nobody is pointing me in any particular direction. In volume texture.. the vertices are fixed on the edges of the box. The 3D texture is mapped over the box. How can I calculate the vertex normals that are required for the lighting? Any direction in this regard will help me alot. Thanks, Ajit

I believe you are talking about illuminating volume renderings. I suggest you look at the following link:

High-Quality Volume Graphics on Consumer PC Hardware

These are Siggraph course notes, look especially at the section about illumination. There's a lot of research going on in this area, but the stuff is generally not easy. In volume rendering no vertices are used to compute face normals, but instead illumination is computed on non-polygonal isosurfaces.

Hope this helps at least a bit,

George

Thanks George,
The illumination model link you have suggested is having some good material.
I was looking for calculations of vertex normals and I was wrong in that sense. Thanks for giving me particular direction.
Thanks again,
AjitG

I'm just browsing through that material as well, because it interests me a bit. There's a great PPT presentation on volume rendering illumination on that page. It explains how gradients can be used instead of normal vectors to compute illumination. I believe that's what you're looking for.

Cheers,

George

[Edited by - bboyBladeJ on July 5, 2006 9:09:43 AM]