[osg-users] Problem with bump map/shadowing and osg 3.1.1 to 3.2.0

[Alexandre Vaillancourt]

Hello

We've just noticed that we had issues with bump map and shadowing after
upgrading from 3.1.1 to 3.2.0 and I was wondering if it was a known issue
and if there were some ways to fix it. The issue is that the nodes that use
both features (bump map AND shadowing) are not visible.

I'm not familiar with the techniques used to do these two features (this
includes shaders, I'm clueless about this), and the person who implemented
them in our software is no longer with us.

I think the shadow is produced by using osgShadow/ViewDependentShadowMap,
and a shader is used for bump mapping. (Originates from there:
http://www.ozone3d.net/tutorials/bump_mapping_p4.php -- I'll add the code
at the bottom of the email.)

So, is this a known issue and is there a fix for it? Or any pointers on
where I should start looking to fix it? (I'm aware that no one but us know
our software is done so it's quite not feasible to really pinpoint where
the issue is coming from.)

If you need more information I'd be glad to come back to you with it.

Thanks!

[code]

[Vertex_Shader]
        
varying vec3 lightVec;
varying vec3 eyeVec;
varying vec2 texCoord;
attribute vec3 vTangent;
                                        

void main(void)
{
        gl_Position = ftransform();
        texCoord = gl_MultiTexCoord0.xy;
        
        vec3 n = normalize(gl_NormalMatrix * gl_Normal);
        vec3 t = normalize(gl_NormalMatrix * vTangent);
        vec3 b = cross(n, t);
        
        vec3 vVertex = vec3(gl_ModelViewMatrix * gl_Vertex);
        vec3 tmpVec = gl_LightSource[0].position.xyz - vVertex;

        lightVec.x = dot(tmpVec, t);
        lightVec.y = dot(tmpVec, b);
        lightVec.z = dot(tmpVec, n);

        tmpVec = -vVertex;
        eyeVec.x = dot(tmpVec, t);
        eyeVec.y = dot(tmpVec, b);
        eyeVec.z = dot(tmpVec, n);
}
        
[Pixel_Shader]

varying vec3 lightVec;
varying vec3 eyeVec;
varying vec2 texCoord;
uniform sampler2D colorMap;
uniform sampler2D normalMap;
uniform float invRadius;

void main (void)
{
        float distSqr = dot(lightVec, lightVec);
        float att = clamp(1.0 - invRadius * sqrt(distSqr), 0.0, 1.0);
        vec3 lVec = lightVec * inversesqrt(distSqr);

        vec3 vVec = normalize(eyeVec);
        
        vec4 base = texture2D(colorMap, texCoord);
        
        vec3 bump = normalize( texture2D(normalMap, texCoord).xyz * 2.0 - 1.0);

        vec4 vAmbient = gl_LightSource[0].ambient * gl_FrontMaterial.ambient;

        float diffuse = max( dot(lVec, bump), 0.0 );
        
        vec4 vDiffuse = gl_LightSource[0].diffuse * gl_FrontMaterial.diffuse *
                                        diffuse;        

        float specular = pow(clamp(dot(reflect(-lVec, bump), vVec), 0.0, 1.0),
                         gl_FrontMaterial.shininess );
        
        vec4 vSpecular = gl_LightSource[0].specular * gl_FrontMaterial.specular 
*
                                         specular;      
        
        gl_FragColor = ( vAmbient*base +
                                         vDiffuse*base +
                                         vSpecular) * att;
}


[/code]

--
Alexandre Vaillancourt

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