The definition of "inside" is really an application issue, as not all models are hulls.
Adrian's suggestion seems like it would work for you. Use last frame's wand position as your start, and the current position as the end of a line segment, then interest with that line segment. If you cross a polygon boundary, then you get a positive intersection back and know which subgraph's geometry was crossed by the wand motion. -Paul > Hi, > I don't really have a direction, as in the case with a mouse > (x,y point and into the screen). I have a point in 3-space, > and I need to know if that point is inside any model. This > goes with my other question relating to moving something > around. Once I determine that the wand is inside a model, > then I want the model to follow the wand around. > > Thanks, > Dave > > > Adrian Egli wrote: > > Hi Dave, > > > > i don't understand what you are doing. Do you like to get a surface > > point back? Do you like to get a line intersected point > back. Do you > > like a point inside the model back. > > So one technique is the line > > intersection. You define a line segment by a starting point and a > > ending point, then let intersect this with the scene As > result you get > > back all intersections, and then you can decide wether the > point is on > > the line and has intersected with the models surface or not. > > > > may this short answer help you, may not. > > > > /adegli > > > > 2007/8/15, Dave Pugmire <[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]>>: > > > > Hi, > > I need to determine the following. Given a 3D point, > which models > > contain the point. I'm not seeing anything to do this off hand. > > Something easy is to grab the bounding volume for the > Geode, and see if > > the point is inside, but I'd like to get something more > accurate. > > > > Thanks, > > Dave > > > > _______________________________________________ > > osg-users mailing list > > [email protected] > > <mailto:[email protected]> > > > > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph. > > org > > > > > > > > > > -- > > ******************************************** > > Adrian Egli > > > > > > > ---------------------------------------------------------------------- > > -- > > > > _______________________________________________ > > osg-users mailing list > > [email protected] > > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph. > > org > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-opensce negraph.org _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
