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
