Jim Wilson wrote: > I can see what you are saying...but the aircraft (in the cockpit view) > is actually a different scene graph.
But it's under the same camera (oddly, ssg puts the global camera "outside" the graph, when it's logically the top-level node of the graph), and has the same double-transform problem; it just doesn't happen to use the terrain frame for anything. > Really I've got to get more into ssg to understand how all this > works better. For some reason I seem to have an easier time > understanding the lower level opengl stuff now than plib (which > probably sounds backwards). I have the same trouble. You can debug OpenGL transformations by looking at code and inspecting the matrices via printf where you know the problem is. With plib, you have to stare at a scene graph dump. These are really useful, by the way -- just call the print() method on the top level node. The only significant problems are that it's 10 megabytes of dump, mostly of tiles that aren't interesting; and that most of our nodes don't have names -- I added a bunch of setName() calls to the ssg nodes to tell where I was. > My first concern would be about the overhead of transforming the > terrain each frame (lots and lots of vertices). You don't transform the vertices in memory -- just push an extra matrix on the stack and OpenGL will combine them for you. The extra performance cost is almost exactly zero (one matrix multiplication per frame). > If it can be done, I think my earlier suggestion of rendering the > Cockpit with no position offsets might work. Can't we render > everything else and then lastly set the camera to the pilot's nose Sure thing. That's basically the same idea, but it works only for the cockpit. If you fix the double-transform stuff in general, the outside view will stop jittering too. Andy -- Andrew J. Ross NextBus Information Systems Senior Software Engineer Emeryville, CA [EMAIL PROTECTED] http://www.nextbus.com "Men go crazy in conflagrations. They only get better one by one." - Sting (misquoted) _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
