Hello Guy, >I think attaching a shader to each view instead of to object X would be >fine.
I'm not sure if this may be the right thing. Correct me if I'm wrong but this causes in some other issues: 1. I lost the reference to the specifiv object states like Textures, Geometries etc. How does the shader should access this values by differend objects? 2. If i bind it to the view, each object is rendered with this shader. So i shouldn't have the ability to separate shaders and effects between objects ... >If you want to use the callback I think you should create a pre-draw >callback to the object, which I'm not sure possible. The update >callbacks won't help you since it run on all the scene before the >rendering and then only the last setting of the shader will be set, and >it also might affect performance. So I still think attaching shaders to >the views would do what you want. Ok, this is an argument i've to agree. But if If i overload the render method of the composite viewer i could implement "callbacks" (better update sequences) for each object before calling the parent rendering method, so this should be possible. But i am not sure about possible perfomance lacks ... Best regards, Chrsitian Guy wrote: > Hello, > I think attaching a shader to each view instead of to object X would be > fine. > If you want to use the callback I think you should create a pre-draw > callback to the object, which I'm not sure possible. The update > callbacks won't help you since it run on all the scene before the > rendering and then only the last setting of the shader will be set, and > it also might affect performance. So I still think attaching shaders to > the views would do what you want. > > Guy. > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > [EMAIL PROTECTED] > Sent: Tuesday, April 08, 2008 10:55 AM > To: osg-users@lists.openscenegraph.org > Subject: [osg-users] Dilemma with the usage of object Shaders in > differend views ... > > Hi folks, > > actually i am working on object shading with OSG (i.e. Dot3). All works > fine > with single views. Now i am using the osgViewer::Composite viewer and > getting > some dielemma with the usage of object based shaders in differend views > based > on the same scene graph. > > I.e.: I've a single scene node with an object X where i bind the shaders > (at > the object StateSet) for execution. In a single view no problem. If i > use this scene in > multiple views (i.e. A, B) i've the dilemma, that i've to use diffrend > shader params > on the same shader instance. In each rendering pass the params of the > camera > are differend from the point of view of the views, if the views are > rendered. But > the shader has no knowledge about this, it uses only a single uniform to > hook bind > param ... > > I've thought about the following sollutions: > > 1. Using for each view a single shader instance at the same object > StateSet. > Is this usefull? If the scene is complex i could get a huge count of > shaders > which have to be executed. Additionally i'm not sure, if the binding of > the "unused" > shaders produces render artifacts or perfomance issues... > > 2. Using a callback mechanism which switches this values at the shader > before > rendering > > How i could achieve this aim in best way? Has anyone a better solution? > > Best regards, > Christian > > > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or > g > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
