I have also made changes to the RotateCylinderDragger to provide a cylinder ring with a thickness. It is totally optional, but IMHO makes the default behavior work better than a solid cylinder (which typically obscures the geometry you are trying to drag). Gives it a bit more to grab, especially in the case where eyepoint and cylinder axis are near parallel.
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* If the eyepoint and cylinder axis are close to parallel (given some tolerance), then it uses a plane perpendicular to the cylinder axis.
* Otherwise it uses a plane parallel to the cylinder axis oriented towards the eyepoint (previous behavior). This gives decent behavior and is the only path that was taken in the previous code. I kept with previous behavior and that allowed a good bit of code to be removed, simplifying things. There is now no need for the _onCylinder flag, but since there is a public accessor, I wasn't sure how to handle it for backwards compatibility, so I left it in. NOTE - there is no default initialized value, so if it is kept in, it should be set to 'false' to keep same behavior as before. I am not quite sure how the _onCylinder case was supposed to behave as even forcing that path gave undesirable behavior, even with carefully controlled dragging.
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class to encapsulate the pixel coords, SceneView and picking operations in prep for
making the code more general purpose, and less reliant on classes like osgUtil::SceneView and osgUtil::IntersectVisitor.
Vivek's email to osg-submissions:
"I'm happy to release the osgdragger nodekit to the OSG community. I
implemented the nodekit for my company, Fugro-Jason Inc., and they
have kindly agreed to open source it.
The nodekit contains a few draggers but it should be easy to build new
draggers on top of it. The design of the nodekit is based on a
SIGGRAPH 2002 course - "Design and Implementation of Direct
Manipulation in 3D". You can find the course notes at
http://www.pauliface.com/Sigg02/index.html. Reading pages 20 - 29 of
the course notes should give you a fair understanding of how the
nodekit works.
The source code also contains an example of how to use the draggers."
