Hi, Robert I'll try first one.
Thanks Ilia В Чтв, 11/09/2008 в 16:40 +0100, Robert Osfield пишет: > Hi Ilia, > > The way I'd do it be to use a cull callback that decides between two > subgraphs to traverse, one for the front face, one for the back, this > would mean that your scene graph doesn't change with the viewport, and > it'll scale nicely on multi-threaded and multi-camera setups. > > The other approach would be to use a vertex shader to change the > light, or to use two sided lighting, which if you orientate the > normals on the light correctly will work for you. > > Robert. > > On Thu, Sep 11, 2008 at 4:35 PM, Korolyov Ilia <[EMAIL PROTECTED]> wrote: > > Ok. Coming back to first letter - what is right way to do such painting? > > > > As I understand, proper way to change scene - is using UpdateCallback. > > But in UpdateCallback there is no camera information. So I can't define > > suitable color for lines. In CullCallback there is camera information, > > but it's forbidden to change scene in CullCallback. > > > > It's possible to save reference to camera object in UpdateCallback > > descendant. Is it correct way? > > > > Thanks > > Ilia > > > > > > В Чтв, 11/09/2008 в 09:28 -0400, Tomlinson, Gordon пишет: > >> Doubtful really as lines don't have back faces.. > >> > >> Gordon > >> > >> __________________________________________________________ > >> Gordon Tomlinson > >> Email : gtomlinson @ overwatch.textron.com > >> > >> > >> -----Original Message----- > >> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Korolyov > >> Ilia > >> Sent: Thursday, September 11, 2008 9:20 AM > >> To: OpenSceneGraph Users > >> Subject: Re: [osg-users] painting plane > >> > >> Hello > >> > >> This technic working fine for poligons, but is it possible to make this > >> trick to lines? I need exactly two lines, not three as in triangle. > >> > >> I trying in such way > >> > >> group->addChild( geode_with_poligons ); > >> group->addChild( geode_with_lines ); > >> group->getOrCreateStateSet()->setMode( GL_CULL_FACE, GL_BACK | > >> osg::StateAttribute::OVERRIDE | osg::StateAttribute::ON ); > >> > >> Thanks > >> Ilia > >> > >> В Чтв, 11/09/2008 в 14:46 +0400, Korolyov Ilia пишет: > >> > Hello, Robert > >> > > >> > Thanks so much - it really helps > >> > > >> > Ilia > >> > > >> > В Чтв, 11/09/2008 в 11:38 +0100, Robert Osfield пишет: > >> > > Hi Ilia, > >> > > > >> > > If one side of the plane should be red, and the other blue then you > >> > > could render two polygons for the plane, each with opposite winding > >> > > and colour, then use glCullFace(osg::CullFace) to cull the faces to > >> > > give the illusion of changing colour. The other technique you could > >> > > use of two sided colour in the OpenGL lighting/material model, not > >> > > all hardware/drivers supports two side lighting though. > >> > > > >> > > Robert. > >> > > > >> > > On Thu, Sep 11, 2008 at 11:22 AM, Korolyov Ilia <[EMAIL PROTECTED]> > >> > > wrote: > >> > > > Hello > >> > > > > >> > > > I need to draw a plane (more exactly two lines by three points). > >> > > > Problem is in plane color. It must depends on camera position > >> > > > relative plane side - red or blue. > >> > > > > >> > > > I did it with CullCallback, because it's only one way to get > >> > > > access to camera, which I can find. > >> > > > > >> > > > What is right way to do it? > >> > > > > >> > > > Thanks > >> > > > Ilia > >> > > > > >> > > > _______________________________________________ > >> > > > osg-users mailing list > >> > > > osg-users@lists.openscenegraph.org > >> > > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegr > >> > > > aph.org > >> > > > > >> > > _______________________________________________ > >> > > osg-users mailing list > >> > > osg-users@lists.openscenegraph.org > >> > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegrap > >> > > h.org > >> > > >> > _______________________________________________ > >> > osg-users mailing list > >> > osg-users@lists.openscenegraph.org > >> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph. > >> > org > >> > >> _______________________________________________ > >> osg-users mailing list > >> osg-users@lists.openscenegraph.org > >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > >> _______________________________________________ > >> osg-users mailing list > >> osg-users@lists.openscenegraph.org > >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > > > _______________________________________________ > > osg-users mailing list > > osg-users@lists.openscenegraph.org > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
