Hi Ying, The cow.osg model uses osg::TexGen (wrapper for glTexGen) to generate the texture coordinates so the ones assigned to actual geometry are ignored. glTexGen is part of the fixed function pipeline in OpenGL so you don't get this functionality when using shaders. You'll have to implement your own texgen to generate the texture coordinates for this model, or apply your own.
Might I suggest using other models that do have appropriate texture coordinate on them for testing. Robert. On 6 August 2014 15:52, ying song <[email protected]> wrote: > Hello Robert, > > Yes, you are right. The reason is that I didn't set up the texture > coordinates. I did the following change, and I could texturing the model in > the shader. I think the problem is that gl_MultiTexCoord0 actually didn't > give out any texture coordinates in my first code. > > vertex shader: > varying vec2 texCoord; > void main() > { > > gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; > texCoord = gl_Vertex.xy; > } > > fragment shader: > uniform sampler2D texture; > varying vec2 texCoord ; > void main() > { > vec4 color = texture2D(texture, texCoord ); > gl_FragColor = color; > } > > But in this way, I set the texture coordinate according to gl_Vertex, > which is still not what I wanted. > > If I want to render the cow.osg model using shaders, how could I get the > texture coordinates from the osg file? I checked the original osg file of > the cow model, and found that the texture coordinates are all set to (0,0) > in this file. I wonder whether it's necessary to use texture coordinates if > I want to render the cow model. > > If I want to render the exact same cow model using shaders, would you tell > me how could I do it? > > Thanks, > Ying > > robertosfield wrote: > > Hi Ying, > > > > It's not possible to pinpoint what is wrong as you provide no guidance > of how you set up your osg::Geometry. My best guess would be that you > don't set up the texture coordinates. > > > > > > Have a look at the osgshaders example for inspiration, > > > > > > Robert. > > > > > > > > On 5 August 2014 16:31, ying song < ()> wrote: > > > > > Hello everyone, > > > > > > I tried texturing a cube by using shaders, but failed. I already tried > all the way I could think about, but the rendered cube is still totally > black if I use shaders. Could someone help me on this? > > > > > > Here is mycode: > > > cpp file: > > > osg::ref_ptr<osg::Image> image = > osgDB::readImageFile("Images/reflect.rgb"); > > > osg::ref_ptr<osg::Node> node = createNode(); //create the cube > > > > > > osg::StateSet* squareState = node->getOrCreateStateSet(); > > > osg::Program* squareProgramObject = new osg::Program; > > > osg::Shader* squareVertexObject = new osg::Shader( > osg::Shader::VERTEX ); > > > osg::Shader* squareFragmentObject = new osg::Shader( > osg::Shader::FRAGMENT ); > > > squareProgramObject->addShader( squareFragmentObject ); > > > squareProgramObject->addShader( squareVertexObject ); > > > squareVertexObject->loadShaderSourceFromFile( > "shaders/cubeRender.vert"); > > > > squareFragmentObject->loadShaderSourceFromFile("shaders/cubeRender.frag"); > > > squareState->setAttributeAndModes(squareProgramObject, > osg::StateAttribute::ON); > > > > > > osg::ref_ptr<osg::Texture2D> texture = new osg::Texture2D(); > > > texture->setImage(image.get()); > > > > texture->setFilter(osg::Texture::MIN_FILTER,osg::Texture::NEAREST_MIPMAP_NEAREST); > //choose the nearest texture unit value > > > > texture->setFilter(osg::Texture::MAG_FILTER,osg::Texture::LINEAR); //choose > the average of the nearest 4 pixel values as texture > > > > > > osg::Uniform* myTextureU = new > osg::Uniform("myTexture",texture.get()); > > > squareState->addUniform(myTextureU); > > > > > > viewer->setSceneData(node.get()); > > > > > > vertex shader: > > > > > > void main() > > > { > > > > > > gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; > > > gl_TexCoord[0] = gl_MultiTexCoord0; > > > } > > > > > > fragment shader: > > > uniform sampler2D myTexture; > > > > > > void main() > > > { > > > vec4 color = texture2D(myTexture, gl_TexCoord[0].st); > > > gl_FragColor = color; > > > } > > > > > > Thanks a lot! > > > > > > Cheers, > > > ying[/b] > > > > > > ------------------ > > > Read this topic online here: > > > http://forum.openscenegraph.org/viewtopic.php?p=60539#60539 ( > http://forum.openscenegraph.org/viewtopic.php?p=60539#60539) > > > > > > > > > > > > > > > > > > _______________________________________________ > > > osg-users mailing list > > > () > > > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > (http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > ) > > > > > > > > > ------------------ > > Post generated by Mail2Forum > > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=60566#60566 > > > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >
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