[osg-users] Material Properties to Change the Normal Intensity

[Sebastian Messerschmidt]

Hi,

The vertex shader isn't particulary useful, except that your 
tangentspace might be incorrect ;-).

Anyway, If you use the normal in your fragment shader to calculate 
result, don't scale the normal to scale the result, but scale after your 
reflection calculation.
Cheers
Sebastian


> Hi Sebastian,
>
> this is my vertex shader:
>
>
> Code:
>
> #version 130
>
> out vec3 pos;
> out vec3 normal;
> out mat3 TBN;
>
> void main() {
>
> pos = (gl_ModelViewMatrix * gl_Vertex).xyz;
> normal = gl_NormalMatrix * gl_Normal;
>
> vec3 n = normalize(normal);
> vec3 t = normalize(gl_NormalMatrix[0]);
> vec3 b = cross(t, n);
> TBN = transpose(mat3(t, b, n));
>
> gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
> gl_TexCoord[0] = gl_MultiTexCoord0;
>
> }
>
>
>
>
>
> and this is my fragment code:
>
>
> Code:
>
> #version 130
>
> in vec3 pos;
> in vec3 normal;
> in mat3 TBN;
>
> uniform float farPlane;
> uniform bool drawNormal;
> uniform bool drawDepth;
> uniform sampler2D normalTexture;
>
> out vec4 out_data;
>
> void main() {
>
> out_data = vec4(0, 0, 0, 0);
>
> vec3 normNormal;
>
> // Normal for textured scenes (by bump mapping)
> if (textureSize(normalTexture, 0).x > 1) {
> vec3 bumpedNormal = (texture2D(normalTexture, gl_TexCoord[0].st).rgb * 2.0 - 1.0) * TBN;
> normNormal = normalize(bumpedNormal);
> }
>
> // Normal for untextured scenes
> else {
> normNormal = normalize(normal);
> }
>
> vec3 normPosition = normalize(-pos);
> float linearDepth = sqrt(pos.z * pos.z + pos.x * pos.x + pos.y * pos.y);
> linearDepth = linearDepth / farPlane;
>
> if (!(linearDepth > 1)) {
> if (drawNormal) {
> out_data.zw = vec2(max(dot(normPosition, normNormal), 0), 1.0);
> }
>
> if (drawDepth) {
> out_data.yw = vec2(linearDepth, 1.0);
> }
>
> gl_FragDepth = linearDepth;
> }
>
>
>
>
>
> and this is my code:
>
>
> Code:
>
> // define texture attributes
> osg::ref_ptr<osg::StateSet> insertBumpMapTexture(osg::ref_ptr<osg::Image> diffuseImage, osg::ref_ptr<osg::Image> normalImage, osg::ref_ptr<osg::Image> specularImage) {
> osg::ref_ptr<osg::Texture2D> diffuse = new osg::Texture2D();
> osg::ref_ptr<osg::Texture2D> normal = new osg::Texture2D();
> osg::ref_ptr<osg::Texture2D> specular = new osg::Texture2D();
>
> diffuse->setImage(diffuseImage);
> diffuse->setDataVariance(osg::Object::DYNAMIC);
> diffuse->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR_MIPMAP_LINEAR);
> diffuse->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
> diffuse->setWrap(osg::Texture::WRAP_S, osg::Texture::REPEAT);
> diffuse->setWrap(osg::Texture::WRAP_T, osg::Texture::REPEAT);
> diffuse->setResizeNonPowerOfTwoHint(false);
> diffuse->setMaxAnisotropy(8.0f);
>
> normal->setImage(normalImage);
> normal->setDataVariance(osg::Object::DYNAMIC);
> normal->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR_MIPMAP_LINEAR);
> normal->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
> normal->setWrap(osg::Texture::WRAP_S, osg::Texture::REPEAT);
> normal->setWrap(osg::Texture::WRAP_T, osg::Texture::REPEAT);
> normal->setResizeNonPowerOfTwoHint(false);
> normal->setMaxAnisotropy(8.0f);
>
> specular->setImage(specularImage);
> specular->setDataVariance(osg::Object::DYNAMIC);
> specular->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR_MIPMAP_LINEAR);
> specular->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
> specular->setWrap(osg::Texture::WRAP_S, osg::Texture::REPEAT);
> specular->setWrap(osg::Texture::WRAP_T, osg::Texture::REPEAT);
> specular->setResizeNonPowerOfTwoHint(false);
> specular->setMaxAnisotropy(8.0f);
>
> osg::ref_ptr<osg::StateSet> bumpState = new osg::StateSet();
> bumpState->setTextureAttributeAndModes(TEXTURE_UNIT_DIFFUSE, diffuse, osg::StateAttribute::ON);
> bumpState->setTextureAttributeAndModes(TEXTURE_UNIT_NORMAL, normal, osg::StateAttribute::ON);
> bumpState->setTextureAttributeAndModes(TEXTURE_UNIT_SPECULAR, specular, osg::StateAttribute::ON);
> return bumpState;
> }
>
>
>
>
>
> How can I pass this attribute by alpha channel and by uniform per drawable?
>
> Cheers,
> Rômulo
>
> ------------------
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=69766#69766
>
>
>
>
>
> _______________________________________________
> osg-users mailing list
> osg-users at lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org