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)
> >
>
>
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