Hi Tanguy, The best thing to do would be to modify the OSG code and send it to me via osg-submissions list. At that point I can review the changes and get my head around the problem you are trying to address in context. I have to jump between dozens of different topics each day so having things in form that I can easily get my head around is important.
Thanks, Robert. On Thu, Dec 4, 2008 at 4:17 PM, Tanguy Fautre <[EMAIL PROTECTED]> wrote: > > Hi, > > I think I found the bug. Fixed implementation attached. > > If you look at the implementation of the function > osgViewer::View::computeIntersections() taking the nodepath argument, you'll > see that it compute the LocalToWorld transformation using the complete given > path. > > But this is incorrect if the last node of the path is a transformation. In > which case the last transformation is applied twice before computing any > intersections. > > I've currently copy/pasted the current implementation and changed it to a > standalone function so that I could test and use it as a fixed version > without modifying OSG code. See attachment. > > > The two important lines are: > > const osg::NodePath shortPath(nodePath.begin(), nodePath.end() - 1); > > osg::Matrix matrix = osg::computeLocalToWorld(shortPath) * > camera->getViewMatrix() * camera->getProjectionMatrix(); > > > Robert, if you agree with these modifications, what should I do for them to > be integrated back into the trunk? > > > Cheers, > > Tanguy > > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Tanguy Fautre > Sent: Friday 28 November 2008 15:21 > To: osg-users@lists.openscenegraph.org > Cc: Neil Groves > Subject: Spam: [osg-users] View::computeIntersections with a node path > > Hi, > > Has anyone been able to successfully use > osgViewer::View::computeIntersections() taking a node path argument on a > non-trivial scenegraph? > > I currently have a fairly complex scenegraph, but I only want a small > part of it to collide with computeIntersections. When I use > computeIntersections without the nodepath, everything works perfectly. > But as soon as I use the overload with the node path, I get an empty > intersection set. I'm pretty sure the node path I'm giving is correct. > > Looking at the implementation of computeIntersections() with the node > path, the only thing that puzzles me is the use of > osg::computeWorldToLocal(nodePath) before computing the matrix inverse, > I'm not sure I fully understand why this is the case. It seems to me the > whole operation should be LocalToWorldMatrix * ViewMatrix * > ProjectionMatrix instead. > > In any case, if anyone has a working example (which would show > computeIntersections() with a node path is working correctly, or help > finding the mistake I'm doing), it would be appreciated. > > > Regards, > > Tanguy > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
