Hi, > There's no reason to pay any attention to the "default" orientation, since > you can change that with a simple transform concatenated into the dozens of > transforms you're already doing anyway This isn't quite true as the projection matrix (which determines X-right, Y-up, Z-out) is non-invertible and so can't be treated as just another transfom in the stack.
> The 2D screen is where the x-right, y-up comes into play. Yes, until we project on to a display device "up" means very little. It's like a map of the World - which way is "up" isn't very important until the planet's surface is projected on to a piece of paper. But once it is printed on to that piece of paper, the direction of "up" takes on real meaning. I think the salient point is that Matrix_implementation::getLookAt() uses Y-up (the up-vector is (0,1,0). Sure you could rotate the OpenGL projection matrix to allow getLookAt() to use Z-up but I've never seen this happening in the wild and it would only serve to confuse. Cheers, Mik[/i] ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=42809#42809 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
