[osg-users] RTT Camera does not render anything

[Andreas Schreiber]

Hi


I'm trying to generate a texture with a rtt-camera, so I can use this texture later in my main scene.
To verify if the texture is correct I'm trying to put the texture on a quad in my main scene.

I use the following method for the rtt-camera, the red clearColor I used to test what the camera renders, but it did not help me out.


Code:
osg::Camera *createRTTCamera(osg::Camera::BufferComponent buffer, osg::Texture *tex, bool isAbsolute)
{
    osg::ref_ptr<osg::Camera> camera = new osg::Camera;
	osg::Vec4f textureStartColor = osg::Vec4f(1.0, 0.0, 0.0, 0.0);
    camera->setClearColor(textureStartColor);
    camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    camera->setRenderTargetImplementation(osg::Camera::FRAME_BUFFER_OBJECT);
    camera->setRenderOrder(osg::Camera::PRE_RENDER);
	
    if (tex)
    {
        tex->setFilter(osg::Texture2D::MIN_FILTER, osg::Texture2D::LINEAR);
        tex->setFilter(osg::Texture2D::MAG_FILTER, osg::Texture2D::LINEAR);
        camera->setViewport(0, 0, tex->getTextureWidth(), tex->getTextureHeight());
        camera->attach(buffer, tex);
    }
    if (isAbsolute)
    {
        camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
		camera->setProjectionMatrix(osg::Matrix::ortho2D(0.0, 1.0, 0.0, 1.0));
        camera->setViewMatrix(osg::Matrix::identity());
		osg::Vec3 corner = osg::Vec3();
        camera->addChild(createScreenQuad(1.0f, 1.0f, 1, corner));
    }
    return camera.release();
}



In the main part I do the following:

1. I initialize the global texture2D variable with an image

2. Create the rrt camera with color_buffer, the texture (which is global), and 1 for absolute

3. load geometry

4. 	Setup Light, here an example

Code:
osg::ref_ptr<osg::LightSource> sunLight = new osg::LightSource();
	sunLight.get()->setLight(createLightSpot(osg::Vec4(0, 1, 0, 0), osg::Vec4(0, 1, 0, 1)));
	sunLight.get()->setReferenceFrame(osg::LightSource::ABSOLUTE_RF);
	sunLight.get()->setLocalStateSetModes(osg::StateAttribute::ON);



5. Add the light and the geometry to the rtt camera
6. Add the light and the geometry to the main scene

Now there should be the scene on the quad geometry which I generated, but this is always rendered with the color of the light and nothing else on it.
It isn't even a mix of the light color and the clear color of the rtt camera, its just the light color.

Here is my quad generation as well:

Code:
	osg::ref_ptr<osg::Geode> planeRTT = new osg::Geode();
	osg::ref_ptr<osg::Geometry> geometry = new osg::Geometry();
	planeRTT->addDrawable(geometry);

	osg::ref_ptr<osg::Vec3Array> vertexArray = new osg::Vec3Array();
	vertexArray->push_back(osg::Vec3(1, -0.25, -1));
	vertexArray->push_back(osg::Vec3(1, 0.75, -1));
	vertexArray->push_back(osg::Vec3(1, 0.75, 1));
	vertexArray->push_back(osg::Vec3(1, -0.25, 1));
	geometry->setVertexArray(vertexArray);

	osg::ref_ptr<osg::Vec4Array> colorArray = new osg::Vec4Array();
	colorArray->push_back(osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f));
	geometry->setColorArray(colorArray);
	geometry->setColorBinding(osg::Geometry::BIND_OVERALL);

	osg::ref_ptr<osg::Vec2Array> texCoordArray = new osg::Vec2Array();
	texCoordArray->push_back(osg::Vec2(0.0f, 0.0f));
	texCoordArray->push_back(osg::Vec2(1.0f, 0.0f));
	texCoordArray->push_back(osg::Vec2(1.0f, 1.0f));
	texCoordArray->push_back(osg::Vec2(0.0f, 1.0f));
	geometry->setTexCoordArray(0, texCoordArray);

	geometry->addPrimitiveSet(new osg::DrawArrays(GL_TRIANGLE_FAN, 0, 4));
	
	planeRTT.get()->getOrCreateStateSet()->setTextureAttributeAndModes(0, rttTexture.get(), osg::StateAttribute::ON);



Did I miss something or did I mixed up some order?! 
Would be grateful for any help!

... 

Thank you!

Cheers,
Andreas

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http://forum.openscenegraph.org/viewtopic.php?p=63381#63381