On Thursday, 4 November 2004 22:02, Aaron Wilson wrote: > Paul, > NeHe has a good example of how to convert the screen coordinates > into OpenGL coordinates. > http://nehe.gamedev.net/data/articles/article.asp?article=13 > > Aaron
I found that article very helpful. The part I don't understand is how the glReadPixels get's the winZ co-ordinate. I mean I'm looking at a wireframe ellipsoid from an odd angle - how does it know how to return the Z co-ordinate of the surface of the ellisoid? Surely I have to tell it where the surface is so that it knows how to intercept the surface and not try to pick a point into infinity (in front of and behind my cursor)? That is what is not explained anywhere I look. Paul ___________________________________________________________ALL-NEW Yahoo! Messenger - all new features - even more fun! http://uk.messenger.yahoo.com _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d