RE: [openvrml-develop] getting coordinates from ViewPoint- and Sound-Nodes

[S. K. B. <bo...@pa...>]

> -----Original Message-----
> From: S. K. Bose [mailto:bo...@pa...]
> Sent: Thursday, April 11, 2002 12:14 PM
> To: -oli-; ope...@li...
> Subject: RE: [openvrml-develop] getting coordinates from ViewPoint- and
> Sound-Nodes
> 
> 
> 
> 
> > -----Original Message-----
> > From: ope...@li...
> > [mailto:ope...@li...]On Behalf Of -oli-
> > Sent: Wednesday, April 10, 2002 8:46 PM
> > To: ope...@li...
> > Subject: [openvrml-develop] getting coordinates from ViewPoint- and
> > Sound-Nodes
> 
> > (1) How can I get the coordinates of the actual ViewPoint, i.e. 
> including 
> > the user navigation transformations, in the VRML-world 
> coordinate system 
> > (_not_ the OpenGL coordinate system)?
> > I have found some code concerning this in VrmlScene.render(). But 
> > how can I 
> > get the position out of the modelview-matrices used here? After a 
> > MV.getTransform(pos,...) the values in pos don't change even if I 
> > turn the 
> > scene around the viewer (or the viewer around the scene, which 
> > probably is 
> > more correctly). I also need some information (e.g. 
> view-up-vector) about 
> > the ViewPoint's orientation.
> 
> You go through the code "NodeBillboard::billboard_to_matrix(...)" or 
> "NodeLOD::render(..)". Here you will find how to get viewer 
> position w.r.t.
> local coordinate system. For your case don't inverse it.
>
If I am right, probably you can use local coordinate system to implement
sound node instead of going for world coordinate. 
 
Thanks,
 
Bose