robertosfield wrote: > > Hi Fred, > > I would be inclined to think this is more of an issue of expectation > rather than a bug in computeIntersections/LineSegmentIntersector. The > code is such that save for numerical precision issues it will work > exactly the same for all triangles, so if it works once then it's > likely to work all the time, and if it fails once it'll fail all the > time. The code has been in place for quite a while so I would expect > it to be working OK otherwise we'd have heard lots of more reports of > problems. > > Most likely answer is simply that the winding of the triangles you are > intersecting resulting in the normals that it's reporting. Please not > face normals derived from the triangles themselves can be and usually > are different than vertex normals at the corners of the triangles - > they can even be pointing in different directions as vertex normals > are specified at geometry creation time and needn't bare any > connection to the faces. >
Thanks. I figured out how picking works with respect to the vertex ordering. However I do see unexpected behavior with some of our larger models, whereby the first intersection is not returned. I double checked and the vertex ordering is fine. Problems show up within the same triangle. I can consistently repro this bug with very large models I can't give away for analysis unfortunately. I can however try to find a small repro with a file in the examples folder or, as suggested by J.P., I can try changing the picking precision in the source code. ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=20744#20744 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
