Hi,

I found osgManipulator on OSG SVN, and since I was beginning to write quite the 
same thing (for VR interaction), I had a look to see if I could save some time 
by adapting and using it for 6DOF devices.
osgManipulator has been designed to be used with a mouse, so there a lots of 
"projectWindowXYIntoObject" stuff.  However, it is in fact often only used to 
get a nearPoint and farPoint and then working with a LineSegment (which is fine 
to me as VR devices give that kind of info). Then all computations occur in 
Object Space.
The only problem comes with the LineProjector (Projector.cpp), which work in 
windows space. I really don't understand why, and I've changed the 
LineProjector::project function to do computations in object space (which is in 
fact way much simpler). I haven't seen any difference in the behaviour (less 
than 1% difference on projected point coordinates in local space).

Is there a particular reason that I haven't seen for LineProjector::project to 
work in windows space ?

On a more general level, many fonctionnalities of OSG regarding interaction, 
picking and so on are "mouse" oriented (asking for mouse_x, mouse_y, projection 
matrix, near/farPlanes) but in fact often work with nearPoints and farPoints, 
which are more related to ray picking (that also work in VR) than just mouse 
picking. Is it a design intend, or would it be possible to disconnect this 
fonctionnality from mouses and allow an API "ray picking oriented" ?
   
   Luc


Luc FRAUCIEL - BRGM
Unité Calcul, 3D et réalité virtuelle
Service Systèmes et Technologies de l'Information
3, av C. Guillemin BP 6009 - 45060 Orléans Cedex 2, France
Tél. 02 38 64 35 65
Fax 02 38 64 39 70
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