On Mon, 2007-11-12 at 18:17 +0000, Robert Osfield wrote: > The most flexible approach would be to use a Camera that moves over > the 2D subgraph using the view frustum to clip out what you don't need > to see on screen. The Camera could be a straight HUD camera and > render on top or a RTT Camera, the later would have the added > flexibility of rendering onto 3D objects, but this is really an > orthogonal issue, once you have a Camera for rendering you scrollable > view you are done. For the scrolling you could either update the view > matrix or the projection matrix, personally I'd update the view matrix > as one can then think of scolling as panning across a scene and even > use camera manipulators for it
Well, I must admit that a lot of what you're saying here I'm familiar with in concept but not in implementation. For example, I've never worked directly with setting Clipping Planes in OpenGL, and I don't think interfacing with them is non-trivial. Hell, I wouldn't even know where to begin to find out how to calculate the necessary A, B, C, and D values for my 2D Orthographic projection, nor do I have any understanding of the complications with regards to how a clipping pane is affected by the current matrices and how they are affected by state (there are some previous posts on this in my archives). Looks like I may need to go back to formula and review some core concepts... > _______________________________________________ > 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
