Is the glow uniform from all aspects? The reason I ask this sounds similar to work I did for a lightpoint halo, which is uniform, but does not intersect with geometry and disappears when the light source is occluded.
-B > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:osg-users- > [EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] > Sent: Monday, January 08, 2007 8:05 AM > To: osg users > Subject: RE: [osg-users] Light point depth > > I've had the same problem in the past and my solution, purely on the > modelling side, was to offset my glow polygon along the axes that points > towards the eye (+Y I think). Then the billboard is positioned at the > light > source but the glow is drawn a little closer towards the eye. So as you > look > more obliquely, the glow polygon is not immediately clipped in half. It > does > start to get clipped at some angle but the effect is much less serious. > For > me it was adequate for all my small lights in the scene and you might need > to > experiment with the offset distance which depnds on the light size. I used > the occlusion method too but only for really bright objects like the sun > with > lens flare etc. > > Regards, Simon > _______________________________________________________________________ > > Simon Mills > Modelling & Simulation Section (TEC-SWM) Tel: +31 (0)71 565 3725 > European Space Agency (ESA/ESTEC) Fax: +31 (0)71 565 5420 > Postbus 299, 2200AG Noordwijk e-mail: [EMAIL PROTECTED] > The Netherlands http://simulation.esa.int > _______________________________________________________________________ > > > > Roderick Kennedy > <Roderick.Kennedy@ > evos.net> > To > Sent by: osg users > osg-users-bounces@ <[email protected]> > openscenegraph.net > cc > > > Subject > 04/01/2007 17:26 RE: [osg-users] Light point depth > > > Please respond to > osg users > <[EMAIL PROTECTED] > negraph.net> > > > > > > > No now I think about it, that wouldn't work. What you need is for the > actual > depth test to depend on the sprite centre, which can't be done with the > usual > z-test. Sounds like the occlusion test is the way forward. > > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Roderick > Kennedy > Sent: 04 January 2007 15:57 > To: osg users > Subject: RE: [osg-users] Light point depth > > How about a billboard sprite shader that takes z depth from the sprite > centre? > > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Zach Deedler > Sent: 04 January 2007 15:37 > To: 'osg users' > Subject: RE: [osg-users] Light point depth > > Hmmm, looks like there is no simple solution. For now, I'll just try to > offset the light points more, and put the more elegant solutions on the > back > burner. Thanks for all the ideas everyone. > > > > Zach > > > > > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Paul Martz > Sent: Thursday, January 04, 2007 10:17 > To: 'osg users' > Subject: RE: [osg-users] Light point depth > > > I don't care if the light point occludes objects within a few meters. > Would > using a PolygonOffset work with a meter offset? > I believe PolygonOffset won't work for you when viewing the light at an > obtuse angle, say from the side, and slightly in front of, the vehicle. In > such a case, the further headlight would need a greater depth offset than > the > near headlight to in order to completely avoid intersecting the vehicle > body. > > In general, whether PolygonOffset produces acceptable results or not > varies > depending on available depth buffer precision, and how you've set your > near/far planes. > > Paul Martz > Skew Matrix Software LLC > http://www.skew-matrix.com > 303 859 9466_______________________________________________ > osg-users mailing list > [email protected] > http://openscenegraph.net/mailman/listinfo/osg-users > http://www.openscenegraph.org/ > > _______________________________________________ > osg-users mailing list > [email protected] > http://openscenegraph.net/mailman/listinfo/osg-users > http://www.openscenegraph.org/ _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
