[osg-users] [Depth Buffer rendering]

[Mathieu Schoutteten]

Hello,
I would like to create an effect (using osgFX) which render the depth
buffer. I'm using a RTT and then apply the texture to the object but i'm
having some problem for mapping correctly the texture on the object (see
capture in attachment). My RTT camera must be similar to my viewer camera,
so i've tried to play with the matrix but without success. In fact for my
program, the texture should be use as an input of a shader.
can someone help me ? am i doing the right things ?
Thanks,
Mathieu

Here is a fragment of the code i'm using:
/////////////////////////////////////////////////////////////////////////
    const unsigned int tex_depth_width = 1024;
    const unsigned int tex_depth_height = 1024;

    osg::Texture2D* _tex_depth = new osg::Texture2D;
    _tex_depth->setTextureSize(tex_depth_width, tex_depth_height);
    _tex_depth->setInternalFormat(GL_DEPTH_COMPONENT);
    _tex_depth->setWrap(osg::Texture2D::WRAP_S,
osg::Texture2D::CLAMP_TO_BORDER);
    _tex_depth->setWrap(osg::Texture2D::WRAP_T,
osg::Texture2D::CLAMP_TO_BORDER);
    _tex_depth->setFilter(osg::Texture2D::MIN_FILTER,
osg::Texture2D::LINEAR);
    _tex_depth->setFilter(osg::Texture2D::MAG_FILTER,
osg::Texture2D::LINEAR);

    osg::Camera* camera = new osg::Camera;
    camera->setClearMask( GL_DEPTH_BUFFER_BIT );
    camera->setClearColor( osg::Vec4(1.0f,1.0f,1.0f,1.0f) );
    //camera->setReferenceFrame(osg::Camera::ABSOLUTE_RF);
    camera->setComputeNearFarMode( osg::Camera::DO_NOT_COMPUTE_NEAR_FAR );
    camera->setViewport(0, 0, tex_depth_width, tex_depth_height);
    camera->setViewMatrix( osg::Matrix::identity() );
    camera->setRenderOrder(osg::Camera::PRE_RENDER);
    camera->setRenderTargetImplementation(osg::Camera::FRAME_BUFFER_OBJECT);
    camera->attach(osg::Camera::DEPTH_BUFFER, _tex_depth);
    camera->addChild( _scene );

    root->addChild( camera );
    root->addChild( _scene );

    const unsigned int tex_depth_unit = 0;
    osg::StateSet* ss = new osg::StateSet;
    ss->setTextureAttributeAndModes(tex_depth_unit, _tex_depth,
osg::StateAttribute::OVERRIDE | osg::StateAttribute::ON);
    _scene->setStateSet( ss );
///////////////////////////////////////////////////////////////////
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