I believe you need to Invert the result to see vaules you are expecting http://www.openscenegraph.org/projects/osg/wiki/Support/Tutorials/CameraControl
________________________________ From: osg-users-boun...@lists.openscenegraph.org on behalf of Kris Dale Sent: Fri 8/21/2009 2:00 PM To: osg-users@lists.openscenegraph.org Subject: Re: [osg-users] Orienting a model (matrixtrans) toward a targetlocation? Chris 'Xenon' Hanson wrote: > Kris Dale wrote: > > > I've stepped through the calculations the source goes through and that's > > all coming out the same as I get when I do it by hand, I just don't > > understand where those are coming from. Obviously the position vector is > > inverted (-100 instead of +) and for whatever reason it's not pointing at > > the target location... man.. so confused.. I wish I had paid better > > attention in linear. Hahaha. > > > > The only thing that crosses my mind is that makeLookAt is typically used to > composed > LookAt modelview matrices, not matrices for object positioning. Obviously the > code must > work and be right, since it's used in OSG's positioning code in several > places. I'm > wondering if this usage means there is some non-obvious requirements that > make it > unsuitable for use as an object LookAt? > > -- > Chris 'Xenon' Hanson, omo sanza lettere Xenon AlphaPixel.com > PixelSense Landsat processing now available! http://www.alphapixel.com/demos/ > "There is no Truth. There is only Perception. To Perceive is to Exist." - Xen > _______________________________________________ > osg-users mailing list > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > ------------------ > Post generated by Mail2Forum Even if that were the case, looking at just the raw numbers and nothing else, it's still producing incorrect output isn't it? If I give it (0,0,100) for the eye position, shouldn't (0,0,100, 1) be the final row of the matrix rather than (0,0,-100, 1)? And what about the direction vertices? If osg::Matrix::makeLookAt doesn't work... it looks like I'm back to my original question of trying to figure out what the equations are to finding the correct vectors for x and z when I've already set the y vector to point at the the target position. Curse graphics and their reliance on linear algebra! Then again, it's better than calculus I suppose.... ;) ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=16581#16581 _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
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