You didn't say specifically what part of your posted images was unacceptable. I'm assuming you need to see the back part of an object through the front part, is that the issue?
If so, there are some depth buffer tricks you can use to get closer to "correct", such as disable depth writes, then render back faces, then front faces. This will solve many (but not all) of the issues. I'll add that concave and self-intersecting transparency isn't an issue specific to OSG and OpenGL. It's a long-standing challenge in 3D computer graphics universal to most all APIs. Hope that helps, -Paul > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf > Of Frédéric SPEISSER > Sent: Wednesday, April 16, 2008 11:37 AM > To: OpenSceneGraph Users > Subject: Re: [osg-users] Box transparency. > > I think I had already tested it that way a few months ago > and I think the result were better but artefacts were already visible. > I will retest it before taking a look at osgdepthpeeling example. > > Thanks for your responses, > > > Frédéric > > > Robert Osfield a écrit : > > Hi Frederic, > > > > Break the objects into parts, and for items like legs you > can draw the > > object twice, swaping the triangle order so that the back faces are > > drawn first then the front faces. Its not a full proof way > but it can > > work. > > > > Robert, > > > > On Wed, Apr 16, 2008 at 6:20 PM, Frédéric SPEISSER > > <[EMAIL PROTECTED]> wrote: > > > >> Hi Robert, > >> > >> The problem is that transparency seems not to work for one object > >> itself (see attached image). > >> Osg is making inter-object sorting but no intra-object sorting as > >> far as I understood ? > >> > >> So I tend to think that implementing own solutions (based > on shaders > >> or other techniques) is the only solution... > >> > >> > >> Frédéric > >> > >> > >> Robert Osfield a écrit : > >> > >> > >> > >> > >>> Hi Frederic, > >>> > >>> Rather than needing to sort per triangle it is usually > sufficient to > >>> just break your objects into smaller parts and then let the OSG's > >>> transparent bin sorting make sure objects are drawn in > the correct > >>> order. > >>> > >>> Robert. > >>> > >>> On Wed, Apr 16, 2008 at 3:45 PM, Frédéric SPEISSER > >>> <[EMAIL PROTECTED]> wrote: > >>> > >>> > >>> > >>>> Thank you Joachim, > >>>> > >>>> Yes, I saw the depthpeeling example, but as I my > graphic card is > >>>> not enough powerfull I cannot launch it ... > >>>> Sorting the triangles by depth before rendering is a > solution, but > >>>> as > >>>> > >> my > >> > >>>> point of view is constantly changing, is it possible to > do such a > >>>> sort in real time ? May be should I use vertex shader for this ? > >>>> > >>>> Frédéric > >>>> > >>>> > >>>> > >>>> > >>>> Joachim E. Vollrath a écrit : > >>>> > >>>> > >>>> > >>>> > >>>>> Hello Frédéric, > >>>>> > >>>>> > >>>>> > >>>> > > >>>> > in short: no, it is not supported natively. > >>>> > > >>>> > You have to either sort the triangles by depth before > rendering > >>>> or > >>>> > >> use > >> > >>>> > the depth peeling algorithm. > >>>> > > >>>> > There should be (at least there was) a depth peeling > example you > >>>> > >> could > >> > >>>> > use as a starting point for such an implementation. > >>>> > > >>>> > Regards, > >>>> > Joachim > >>>> > > >>>> > > >>>> > Frédéric SPEISSER wrote: > >>>> > > >>>> >> Hi Paul, hi all, > >>>> >> > >>>> >> I'm still trying to have a nice transparency for > some objects. > >>>> > >> Indeed > >> > >>>> >> even if I use backface culling, the transparency rendering of > >>>> > >> concave > >> > >>>> >> objects seems not to work properly (see attached images). > >>>> >> The only way I found seems to implement an depthpeeling > >>>> algorithm to > >>>> > >> do > >> > >>>> >> order-independant transparency, is that necessary ? > >>>> >> Is concave objects transparency rendering natively not > >>>> supported by >> OpenGL/OpenSceneGraph ? > >>>> >> > >>>> >> > >>>> > > >>>> > > >>>> > > >>>> > >>>> > >>>> > >>>> _______________________________________________ > >>>> osg-users mailing list > >>>> [email protected] > >>>> > >>>> > >> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph > >> .org > >> > >>>> > >>>> > >>> _______________________________________________ > >>> osg-users mailing list > >>> [email protected] > >>> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegrap > >>> h.org > >>> > >>> > >>> > >> _______________________________________________ > >> osg-users mailing list > >> [email protected] > >> > >> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph > >> .org > >> > >> > >> > > _______________________________________________ > > osg-users mailing list > > [email protected] > > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph. > > org > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-opensce > negraph.org _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
