Hello Denis,
When I added vertex shader, the object was not shadowed properly
(with the same exact fragment shader). I suspect I'm doing something
wrong with the texture coordinates in a vertex shader. I looked in
ShadowMap.cpp, it has only fragment shaders. Do you know where can I
find default vertex shader?
When you start using a shader for one part of the pipeline (vertex or
fragment) you need to do everything that that part of the pipeline used
to do (and which is needed by your rendering). In the case of shadows,
you'll notice that the code in ShadowMap.cpp adds an osg::TexGen that
calculates some texture coordinates for texture unit 1. But that's the
fixed pipeline, so you will need to calculate texture coordinates for
unit 1 as glTexGen would in your vertex shader now that it has replaced
the fixed-function vertex processing.
Something like this should work, though you should probably have finer
control over when these are calculated or not:
gl_TexCoord[1].s = dot( ecPosition, gl_EyePlaneS[1] );
gl_TexCoord[1].t = dot( ecPosition, gl_EyePlaneT[1] );
gl_TexCoord[1].p = dot( ecPosition, gl_EyePlaneR[1] );
gl_TexCoord[1].q = dot( ecPosition, gl_EyePlaneQ[1] );
Note that ecPosition is:
vec4 ecPosition = gl_ModelViewMatrix * gl_Vertex;
I also assume you're transforming your texture coordinates for texture
unit 0 properly:
gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0;
Just assigning gl_MultiTexCoord0 to gl_TexCoord[0] will work until you
try to use a texture matrix (osg::TexMat)...
I highly recommend you get/read the Orange Book, as this is all given
there. You can also download the ShaderGen program from 3DLabs (now
hosted on http://mew.cx/glsl since 3DLabs removed it from their site)
which can generate shaders that emulate the fixed pipeline. Note that
for speed, you should probably only use the features you need in your
shaders, so I am not recommending that you generate a shader that does
*all* of what the fixed pipeline would do... Just use what ShaderGen
produces as a guide.
Hope this helps,
J-S
--
______________________________________________________
Jean-Sebastien Guay [EMAIL PROTECTED]
http://www.cm-labs.com/
http://whitestar02.webhop.org/
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