With fixed-function EYE_LINEAR texgen, the planes are multiplied by
the inverse of the modelview in effect when glTexGen() is called, and
these transformed planes are what you get in the vertex shader with
the fixed-function uniforms. With generic uniforms, you can use them
to store anything you want, so no transformation is applied. Becasue
of that, you need to transform the planes yourself before passing them
to your shader.
Leif
On 8/27/06, Botorabi <[EMAIL PROTECTED]> wrote:
hi,
i could fix the problem with eye-space transformation. i multiply the tex gen
matrix by camera's inverse modelview matrix in every frame, now the shadows
work also for transformed nodes. to be honest, i don't know why this
multiplication is needed!? it seems that in older nvidia drivers the built-in
eye linear planes were already multiplied with that inverse matrix before they
were passed to the vertex shader.
cheers
boto
boto wrote:
###########
hi,
unfortunately, it seems that the nvidia driver has another bug, the built-in
uniform gl_ModelViewMatrix it is. see the code below: the vertex position is
transformed to eye-space by multiplying gl_Vertex with gl_ModelViewMatrix.
however that results in wrong shadows, actually no shadows on VRC island -- i
have replaced the eye planes by the matrix 'texgenMatrix' which i pass through
the _MVPT uniform (for the code see the link in my last posting). if i do not
transform the vertices via gl_ModelViewMatrix then only meshes with no
transformation get proper shadows, i.e. the player and other meshes which do
not origin at 0,0,0 get wrong or no shadows :-(
what the hell happened to nvidia? i wonder how it could happen that the ogl
support got broken so radically!?
further help to work-around the new bug would be great.
cheers
boto
"/* \n"
"* Vertex shader for shadow mapping \n"
"* http://yag2002.sf.net \n"
"* 06/27/2006 \n"
"*/ \n"
"uniform mat4 texgenMatrix; \n"
"varying vec4 diffuse, ambient; \n"
"varying vec3 normal, lightDir, halfVector; \n"
"varying vec2 baseTexCoords; \n"
"const int shadowTexChannel = 1; \n"
" \n"
"void main() \n"
"{ \n"
" normal = normalize( gl_NormalMatrix * gl_Normal ); \n"
" lightDir = normalize( vec3( gl_LightSource[ 0 ].position ) ); \n"
" halfVector = normalize( gl_LightSource[ 0 ].halfVector.xyz ); \n"
" diffuse = gl_FrontMaterial.diffuse * gl_LightSource[ 0 ].diffuse; \n"
" ambient = gl_FrontMaterial.ambient * gl_LightSource[ 0 ].ambient; \n"
" ambient += gl_LightModel.ambient * gl_FrontMaterial.ambient; \n"
" \n"
" vec4 pos = gl_ModelViewMatrix * gl_Vertex; \n"
" gl_TexCoord[ shadowTexChannel ] = texgenMatrix * pos; \n"
" gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; \n"
" baseTexCoords = gl_MultiTexCoord0.st; \n"
"} \n"
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Leif Delgass
[EMAIL PROTECTED]
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