kajihara@mcnc.org (Scott "Lord of Sith" Kajihara) (11/10/90)
We have programs that switch between the orthogonal projection mode and the perspective projection mode to view objects. When using ortho or window, the viewpoint is reset to looking down the z-axis. We have the following problems to solve: retaining the same viewpoint when switching from ortho to perspective to ortho projections as one case and resetting the lighting behind the viewpoint when the viewpoint is changed as a second case. Is there any simple way using the defined Model/View and Projection matrices to do this? Thank you, Scott Kajihara -- Scott Akira Kajihara "Insanity is a prerequisite for physics techie-types" mcnc!kajihara kajihara@mcnc.org mcnc!{pyvax|pymvjb|pysgjb}!kajihara kajihara@{pyvax|pymvjb|pysgjb}.nscu.edu kajihara@ncsuphys.BITNET _et al._ of which I am not aware.
karron@KARRON.MED.NYU.EDU (11/11/90)
The ortho call does a hidden translation of the eye position. I was thinking of this problem, and the solution to my mind is to make a wrapper for the ortho call to eliminate the translation effect. This would be by instead of defining a viewing RECTANGLE, force it to be a viewing CUBE, and specify a height and width, not a left and right clipper, etc. I don't know how you would correct for a non square window. I would have to think about that for a few more seconds before I made a better suggestion. Please post your solution, as I do want to be able to switch transforms for these reasons: While a perspective transform looks better, an ortho is much better for sighting things along lines and taking measurements. I also have a better winopen() call idea, and when I get all of this working nicely, I will post it. dan. +-----------------------------------------------------------------------------+ | karron@nyu.edu (mail alias that will always find me) | | Dan Karron | | . . . . . . . . . . . . . . New York University Medical Center | | 560 First Avenue \ \ Pager <1> (212) 397 9330 | | New York, New York 10016 \**\ <2> 10896 <3> <your-number-here> | | (212) 340 5210 \**\__________________________________________ | | Please Note : Soon to move to dan@karron.med.nyu.edu 128.122.135.3 (Nov 1 )| +-----------------------------------------------------------------------------+