> So... I would have though just passing the view matrix as is would the > appropriate thing to do.
Yes, thats right. The problem for me in this case was that I expected, and required the OpenGL view states to be set at the point of the preDrawCallback for a camera. The reason for this is that OpenHaptics, the haptic rendering toolkit which Im depending on is reading the OpenGL modelview matrix during its "pre-haptic-draw". This gets event more complicated as one need to follow the below described loop: Each haptic device is associated to a Camera (due to that one need the View/projection matrices setup before rendering). 0. Draw Haptic Scene 1. for each haptic_device: 1.1 Apply view/projection for associated osg::Camera 1.1 haptic_device->makeCurrent() 1.2 haptic_device->beginDraw() 2. render opengl (any valid geometry call will be caught by haptic API as haptic geometry) 3. Finished: for each camera 3.1 haptic_device->endDraw() Now if the modelview matrix is applied within the renderbin, just before a Leaf is about to be rendered, one has to initialize the haptic rendering there. I do have a HaptiCrenderbin, and HapticRenderLeaf already so that structure is working. The problem is now that the ModelViewMatrix can be pushed/popped several times due to the accumulated state for a RenderLeaf, so there is nowhere I can put my haptic_device->beginDraw() where I know that: Here is where the ModelView matrix is applied to OpenGL. In osg1.x together with Producer, the OpenGL states were applied before the PreDrawCallback, but as you pointed out, that state-change was effectively ignored by OSG. Now I have to decorate the scene with a mechanism that before the haptic part of a scene-graph is rendered, it has to begin the haptic rendering WITH a valid OpenGL context and the correct ModelView matrix applied. I cant really see how I am going to achieve that with callbacks, or even my own RenderBin... I could try to collect all the haptic devices to the HapticRenderBin and try to initialize them there. But thats not really what I am after, I want to associate the HapticDevice to the camera, so that when the scene for a specific camera is about to be drawn, the hapticdevice is properly initialized and used too. I thought preDrawCallback would work like that, but I realize that it doesnt anymore, which is probably a good thing for performance, but less good for me ;-) Does anything of this make sense? Im not sure how to hook the haptic rendering into osg2.0 as it is right now..... Any input is appreciated, cheers, Anders > > > I can get the ViewMatrix, I can also get the MatrixList (of all > > matrices above the camera in the scenegraph), but to match osg and to > > make it as flexible as the rest of osg, how would do this? > > With Viewer cameras there aren't any nodes above it so this should > just be an empty lists. > > > 2. Regarding GraphicsContext, assume that I do need access to a > > graphicsContext in a PreRender, how can I take control of that Context > > avoiding any race condition? > > Now, Im not sure where I get the hang, but it does have something to > > do with the fact that Im accessing OpenGL when I should not... > > Eventhough, when I get into the PreRender callback the Context is > > active. so a simple makeCurrent() would not work. > > The Camera pre draw callback will have the graphics context already > made current so there won't be any need to call makeCurrent yourself. > > If you are finding problems doing OpenGL calls in a Camera pre or post > draw callback then there must be something else wider that is amiss - > the OSG itself should be having the same problems too. > > As for hangs or race conditions on your own code, I can't really comment. > > Robert. > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > -- ________________________________________________________________ Anders Backman Email: [EMAIL PROTECTED] HPC2N/VRlab Phone: +46 (0)90-786 9936 Umea university Cellular: +46 (0)70-392 64 67 S-901 87 UMEA SWEDEN Fax: +46 90-786 6126 http://www.cs.umu.se/~andersb _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
