Hi Andrew, When you say you have a isometric view, to be clear, you mean you have an orthographic projection of the scene? The OSG itself support orthographic projection via the osg::Camera's ProjectionMatrix, the intersection. It can only account for this if the IntersectionVisitor knows about it's setting.
Have you tried the osgViewer::View(er)::computeIntersections(..) method? This method knows about the View's Camera so can account for it's projection matrix. Robert. On Tue, 14 Apr 2020 at 23:35, OpenSceneGraph Users < [email protected]> wrote: > Hi, > I am having a lot of problems with picking with LineSegmentIntersector in > OSG 3.6.5. > > I have reduced the problem to a a simple cube, center 0.5,0.5,0.5 with a > boundingSphere radius of 1.2142 > > I create the intersection with ( x , y are screen coordinates) > > picker=new osgUtil::LineSegmentIntersector ( osgUtil::Intersector::WINDOW, > x, y ); > osgUtil::IntersectionVisitor iv ( picker ); > getCamera()->accept ( iv ); > > > > When I am "close" to the model geometry in an isometric view ( the cube > fills,say, 50% of the screen), this works perfectly. I get the exact > intersections coordinates I expect. > > When I "pull the camera back" from the geometry and the object is much > smaller on the screen, the intersections fail. > > After much debugging, the problem is that the intersector fails the test > of the intersection of the line with the bounding sphere of my model > geometry > > Specifically I send up in > > bool LineSegmentIntersector::intersects(const osg::BoundingSphere& bs) > > > The BoundingSphere is in "model space" , and correct, but the _start and > _end points used in the calculation are incorrect to intersect the sphere > in model space and so the intersection fails. > > _start {_v=0x000001ba7308d300 {13.227287349450325, -2.9785854231569449, - > 5.5167534692525066} } > _end {_v=0x000001ba7308d318 {11.072576448741074, -5.1332963238661939, - > 7.6714332827528793} } > > Any ideas what is going on. It seems although the vector of start and end > is the correct vector ( or the "closer" picking would not work), something > is wrong in the transformation into model space. > > Thx > Andrew > > -- > You received this message because you are subscribed to the Google Groups > "OpenSceneGraph Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/osg-users/4fa21208-3ee7-45d7-a9cf-42a4b8a45d52%40googlegroups.com > <https://groups.google.com/d/msgid/osg-users/4fa21208-3ee7-45d7-a9cf-42a4b8a45d52%40googlegroups.com?utm_medium=email&utm_source=footer> > . > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > -- You received this message because you are subscribed to the Google Groups "OpenSceneGraph Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/osg-users/mailman.84341.1586933770.7167.osg-users-openscenegraph.org%40lists.openscenegraph.org.
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