Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!apple!agate!ucbvax!UCBVAX.BERKELEY.EDU!"Dan Karron From: Dan Karron@UCBVAX.BERKELEY.EDU Newsgroups: comp.sys.sgi Subject: Re: question: lookat() command and twist Message-ID: <9101162321.AA25294@karron.med.nyu.edu> Date: 16 Jan 91 23:21:50 GMT Sender: daemon@ucbvax.BERKELEY.EDU Reply-To: karron@cmcl2.nyu.edu Organization: The Internet Lines: 21 The twisting artifact in lookat() can be avoided by using a negative reverse sequence of modeling transformations to specify your eye position and vector. This is the same as specifying your eye in worldspace and inverting the matrix to give your the eye position viewing transform for that eye position. If this is unclear, I can post a long explanation. The short version is to use modeling transforms for your eye position. +-----------------------------------------------------------------------------+ | karron@nyu.edu (E-mail alias that will always find me) | | Fax: 212 340 7190 * Dan Karron, Research Associate | | . . . . . . . . . . . . . . * New York University Medical Center | | 560 First Avenue \*\ Pager <1> (212) 397 9330 | | New York, New York 10016 \**\ <2> 10896 <3> | | (212) 340 5210 \***\_________________________________________ | | Main machine: karron.med.nyu.edu (128.122.135.3) IRIS 85GT | +-----------------------------------------------------------------------------+