[quote="omdown"] Chris 'Xenon' Hanson wrote: > Tony Horrobin wrote: > > > Hi Kris, > > Is the target moving too? > > Cheers, > > > > > Not at the moment. Currently I'm only worried about figuring out how to > orient in the right direction, I'll worry about tracking at a later time. =) > > > > Chris 'Xenon' Hanson wrote: > > Thrall, Bryan wrote: > > > > > There's osg::Matrix::makeLookAt() > > > > > > > Wow. if only that were named something intuitive that I would have thought > > to look for. > > Or Look At, as the case may be. ;) > > > > Does that answer your question, Kris? > > > > -- > > 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 > > > > Sort of.. that definitely looks like it's going to be what I need, but I > can't seem to get it implemented properly. I've tried it this way: > > > Code: > > osg::MatrixTransform* pMatTrans = dynamic_cast<osg::MatrixTransform*>(node); > osg::Matrix m = pMatTrans->getMatrix(); > osg::Vec3d v = osg::Vec3d( m(3,0) , m(3,1) , m(3,2) ); // save the > location for the eye point > > // if I understand right, the vectors in order are: eye point, lookat point, > up vector, right? > m.makeLookAt( v, osg::Vec3d(0.0, 0.0, 0.0), osg::Vec3d(0.0, 0.0, 1.0) ); > > pMatTrans->setMatrix( m ); > > > > > When I run the code with this lookat call, the model is translated across the > XY plane and doesn't remotely look toward 0,0,0... > > Prior to lookat the getMatrix call the model's getmatrix result is: > > Code: > > > Stars between numbers for ease of reading... someone really needs to make up > a matrix forum manipulator! =P > ____________________________________ > > | 1.65951e-16 * 1 * 0 * 0 | > | -2.47158e-15 * -3.85743e-31 * 1 * 0 | > | 1 * -1.65951e-16 * -2.81642e-16 * 0 | > | -6366.2 * 3182.6 * 3193.6 * 1 | > ____________________________________ > > > > > > After calling makeLookAt the matrix is: > > Code: > > ____________________________________ > > | -0.447157 * 0.366172 * -0.816069 * 0 | > | -0.894455 * -0.183057 * 0.40797 * 0 | > | 0 * 0.912364 * 0.40938 * 0 | > | -1.26565e-13 * 3.71925e-13 * -7801.06 * 1 | > ____________________________________ > > > > > > I assume I'm simply calling something wrong somewhere... can someone point > me in the right direction?[/code]
Okay an update on this, I've tried it with a far more simple example and tried working through the equations in the source code by hand... something isn't quite right somewhere and I'm not understanding what, but I come up with the same results by hand as I do using the makeLookAt... I tried just using: eye ( 0, 0, 100 ) center ( 0, 0, 0 ) up ( 0, -1, 0 ) The resulting matrix I get from this is: Code: -1 0 0 0 0 -1 0 0 0 0 1 0 0 0 -100 0 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. ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=16577#16577 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
