Hi Chris, I have read your post but didn't spend time looking at the specific code implementation as it's hard to know what you are actually attempting to do - knowing exactly what you are trying to achieve is precursor to knowing whether the approach you are taking is appropriate or not.
My first question would be, when you say "whatever other application the user wishes to run" what do you actually mean? It's so open ended to what this might be. Are you talking other things on the desktop such as other programs that might be running? Or is it you want a 3D overlap ontop of 2D UI elements? Or just a 3D scene with various overlays onto of it all drawn in OpenGL/OSG. Also when you say the osghud example doesn't work for you, what do you mean? What you should see when you run osghud and have OpenSceneGraph-Data on your path so it can find the 3D dumptruck model is a 3D truck with a text overlay and transparent quad that form a HUD. Robert. On 1 September 2014 14:13, Chris Hidden <[email protected]> wrote: > Hello OSGers. > > I have been trying to implement a HUD in my unorthodox application. I am > currently displaying 3 models to the screen where I have everything else > transparent. Thus the application works as an overlay on top of whatever > other application the user wishes to run. To do this I am using the > pbuffer in OSG, where I copy all the pixel info over into a struct and then > pre multiply the alpha values of everything and then render it back to the > screen. > > Because of this I have a very specific way in which I set up my scene and > camera: > > > Code: > > osg::ref_ptr<osg::Referenced> windata = new > osgViewer::GraphicsWindowWin32::WindowData(hWnd); > > // Establish Viewer and Camera; > g_viewer = new osgViewer::Viewer(); > g_camera = new osg::Camera; > g_camera = g_viewer->getCamera(); > > // Create and assignTraits for the Graphics Context > osg::ref_ptr<osg::GraphicsContext::Traits> traits = new > osg::GraphicsContext::Traits; > initOSGTraits > (*traits, windata); > osg::ref_ptr<osg::GraphicsContext> gc = > osg::GraphicsContext::createGraphicsContext(traits.get()); > > //Set camera state > g_camera->setGraphicsContext (gc); > g_camera->setDrawBuffer > (GL_NONE); > g_camera->setReadBuffer > (GL_NONE); > g_camera->setProjectionMatrixAsPerspective (30.0f, > (double)sWidth / (double)sHeight, 1.0, 1000.0); > g_camera->setViewport > (new osg::Viewport(0, 0, sWidth, sHeight)); > g_camera->setClearColor > (osg::Vec4f(0.0f, 0.0f, 0.0f, 0.0f)); > g_camera->setRenderOrder > (osg::Camera::PRE_RENDER); > g_camera->setRenderTargetImplementation > (osg::Camera::FRAME_BUFFER_OBJECT); > > // Set camera direction and perspective > osg::Vec3d eye = osg::Vec3d(0, -100, 0); // > position of the camera > osg::Vec3d center = osg::Vec3d(0, 0, 0); // where does the > camera look. > osg::Vec3d up = osg::Vec3d(0, 0, 1); // the up > vector of the camera > g_camera->setViewMatrixAsLookAt(eye, center, up); > > // Establish PBuffer using OSG's image object. Attach it to the camera. > g_image = new osg::Image(); > g_image->allocateImage(sWidth, sHeight, 1, GL_RGBA, > GL_UNSIGNED_BYTE); > g_camera->attach(osg::Camera::COLOR_BUFFER, g_image); > > // Set Callback for adding textures. Makes sharing textures > possible. > osgDB::Registry::instance()->setReadFileCallback(new > ReadAndShareImageCallback); > osgDB::Registry::instance()->getOrCreateSharedStateManager(); > > osg::ref_ptr<osg::Group> models = InitModels(); > osg::ref_ptr<osg::Group> root = new osg::Group; > root->addChild(models); > > // Run OSG optimizer for efficiency. > osgUtil::Optimizer optimizer; > optimizer.optimize(root.get()); > > //Set up threads to windows, getScene data and set GL mode for > rescaling normals. > g_viewer->realize(); > g_viewer->setSceneData(root.get()); > root->getOrCreateStateSet()->setMode(GL_NORMALIZE, > osg::StateAttribute::ON); > > > > > > > I tried using the example from the OSG for beginners book in chapter 7: > Creating an HUD camera. I also tried to follow the example here ( > http://trac.openscenegraph.org/projects/osg//browser/OpenSceneGraph/trunk/examples/osghud/osghud.cpp). > Unfortunately none of these seemed to work for me. In fact nothing showed > up on my screen at all. I was thinking it may be because of the way I > define my camera matrix. Maybe not, Im a bit too much of a newbie to know. > > Anyways, I figured a HUD can just as well be a quad that is right up close > to the camera. So I used this code : > > > Code: > > osg::ref_ptr<osg::Geode> geod = new osg::Geode; > osg::ref_ptr< osg::Geometry> geom = new osg::Geometry; > osg::ref_ptr<osg::Vec3Array> verts = new osg::Vec3Array; > osg::ref_ptr<osg::Vec3Array> norms = new osg::Vec3Array; > osg::ref_ptr<osg::Vec4Array> colors = new osg::Vec4Array; > > float depth = -99.0f; > > verts->push_back(osg::Vec3((1.0f / 3.0f), depth, (1))); > verts->push_back(osg::Vec3((1), depth, (1))); > verts->push_back(osg::Vec3((1), depth, -(1))); > verts->push_back(osg::Vec3((1.0f / 3.0f), depth, -(1))); > norms->push_back(osg::Vec3(0.0, 0.0f, 0.0f)); > colors->push_back(osg::Vec4(1.0f, 1.0f, 1.0f, 0.8f)); > geom->setVertexArray(verts); > geom->setNormalArray(norms, osg::Array::BIND_OVERALL); > geom->setColorArray(colors, osg::Array::BIND_OVERALL); > geom->addPrimitiveSet(new osg::DrawArrays(GL_QUADS, 0, 4)); > osg::ref_ptr<osg::StateSet> stateset = geom->getOrCreateStateSet(); > stateset->setMode(GL_BLEND, osg::StateAttribute::ON); > stateset->setRenderingHint(osg::StateSet::TRANSPARENT_BIN); > geod->addDrawable(geom); > > > > > After playing around I realized that the 0,0 point of the quad was in fact > right in the middle of my scene. But by using the z depth of -99 which is > 1 point off my camera z depth I can use the [0,1] range to make it fit > where I want. Thus I get a nice horizontal bar along the left side of the > screen. > > Now this feels like a somewhat unusual way of doing things. How would I > do this in a more professional way or standardized way, I guess I should > say? Also on a side note, I only get about 36 fps with this application at > the moment. If anyone feels inspired to give me some tips on how to make > this more efficient that would be most appreciated. > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=60885#60885 > > > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >
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