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Bump Mapping ++

Hello,

Bump Mapping in OpenGL with Multitexturing and dot3 ARB extentions ( no 
shaders ).

References :

http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
http://www.paulsprojects.net/opengl/bumpmap/bumpmap.html
http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=22


Now my questions:

1. Bump mapping recquires a light. Front faces will appear "bump" and 
back faces will be totally dark ( no lights on them ). Does someone know 
if It's possible to see back faces not black but just a little bit 
darker, using the same multitexturing/dot3 process ?

2. Based on the references tutorials, does someone knows if its ( easily 
) possible to set multi lights ( more than just one ) at low cost ?


Thank you all,

Julien MEYER
JADEWARE
-- 
Game Programming Docs, Code snippets and more :
http://jadeware.net/dev.html
0
Julien
9/18/2007 7:49:25 PM
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On Sep 18, 9:49 pm, Julien MEYER <m...@privacy.net> wrote:
>
> 1. Bump mapping recquires a light. Front faces will appear "bump" and
> back faces will be totally dark ( no lights on them ). Does someone know
> if It's possible to see back faces not black but just a little bit
> darker, using the same multitexturing/dot3 process ?
>

There's no specular or diffuse light on a backfaced
polygon so you can't do bump mapping directly.

The only way would be to draw the scene twice
using glCullFace() to select front/back facing
polygons and use a darker light for the backfaced
ones.

> 2. Based on the references tutorials, does someone knows if its ( easily
> ) possible to set multi lights ( more than just one ) at low cost ?
>

I don't think you can do it without a shader.


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0
fungus
9/20/2007 4:30:40 AM
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