#include #include #include #include #include #include #include #include #include #include // This function builds a textured quad osg::Node *build_quad(osg::Texture2D *tex) { osg::Geometry *geo = new osg::Geometry; osg::Vec3Array *vx = new osg::Vec3Array; vx->push_back(osg::Vec3(-10, 0, -10)); vx->push_back(osg::Vec3(10, 0, -10)); vx->push_back(osg::Vec3(10, 0, 10)); vx->push_back(osg::Vec3(-10, 0, 10)); geo->setVertexArray(vx); osg::Vec3Array *nx = new osg::Vec3Array; nx->push_back(osg::Vec3(0, -1, 0)); geo->setNormalArray(nx); geo->setNormalBinding(osg::Geometry::BIND_OVERALL); osg::Vec2Array *tx = new osg::Vec2Array; tx->push_back(osg::Vec2(0, 0)); tx->push_back(osg::Vec2(1, 0)); tx->push_back(osg::Vec2(1, 1)); tx->push_back(osg::Vec2(0, 1)); geo->setTexCoordArray(0, tx); geo->addPrimitiveSet(new osg::DrawArrays(GL_QUADS, 0, 4)); geo->getOrCreateStateSet()->setTextureAttributeAndModes(0, tex); osg::Geode *geode = new osg::Geode; geode->addDrawable(geo); return geode; } void build_world(osg::Group *root) { int width = 2048; int height = 2048; // create and configure the texture that we're going // to use as target for render-to-texture osg::ref_ptr tex = new osg::Texture2D; tex->setTextureSize(width, height); tex->setInternalFormat(GL_RGBA); tex->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR); tex->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR); tex->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE); tex->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP_TO_EDGE); // create and configure a framebuffer object. // We attach the texture to the first color buffer, // and we attach a simple offscreen image (RenderBuffer) // to the depth buffer in order to allow depth operations osg::ref_ptr fbo = new osg::FrameBufferObject(); fbo->setAttachment(GL_COLOR_ATTACHMENT0_EXT, osg::FrameBufferAttachment(tex.get())); fbo->setAttachment(GL_DEPTH_ATTACHMENT_EXT, osg::FrameBufferAttachment(new osg::RenderBuffer(width, height, GL_DEPTH_COMPONENT24))); osg::ref_ptr subgraph = osgDB::readNodeFile("cow.osg"); if (!subgraph) return; const osg::BoundingSphere& bs = subgraph->getBound(); if (!bs.valid()) { return; } osg::ref_ptr camera = new osg::CameraNode; camera->setClearColor(osg::Vec4(0.1f,0.1f,0.3f,1.0f)); camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); camera->setViewport(0, 0, width, height); // set the camera to render before the main camera. camera->setRenderOrder(osg::CameraNode::PRE_RENDER); float znear = 1.0f*bs.radius(); float zfar = 3.0f*bs.radius(); // 2:1 aspect ratio as per flag geomtry below. float proj_top = 0.5f*znear; float proj_right = 0.5f*znear; znear *= 0.9f; zfar *= 1.1f; // set up projection. camera->setProjectionMatrixAsFrustum(-proj_right,proj_right,-proj_top,proj_top,znear,zfar); // set view camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF); camera->setViewMatrixAsLookAt(bs.center()+osg::Vec3(0.0f,2.0f,0.0f)*bs.radius(),bs.center(),osg::Vec3(0.0f,0.0f,1.0f)); // tell the camera to use OpenGL frame buffer object where supported. camera->setRenderTargetImplementation(osg::CameraNode::FRAME_BUFFER_OBJECT); // attach the texture and use it as the color buffer. camera->attach(osg::CameraNode::COLOR_BUFFER,tex.get()); // attach the subgraph camera->addChild(subgraph.get()); // attach the camera to the main scene graph. root->addChild(camera.get()); // now create a simple quad that will be rendered // in the main framebuffers. The quad's texture // will be the content of the FBO's color buffer root->addChild(build_quad(tex.get())); } int main() { osg::ref_ptr root = new osg::Group; build_world(root.get()); osgProducer::Viewer viewer; viewer.setUpViewer(); viewer.setSceneData(root.get()); viewer.realize(); while (!viewer.done()) { viewer.sync(); viewer.update(); viewer.frame(); } viewer.sync(); viewer.cleanup_frame(); viewer.sync(); return 0; }