Hi Paul, On Fri, Oct 30, 2009 at 8:32 PM, Paul Martz <[email protected]> wrote: >>> Even more complex would be making it easy for developers to integrate >>> their >>> own shaders with the fixed-function-over-shaders later, so that their own >>> shaders could simply call a function to compute per vertex lighting >>> values, >>> for example. >> >> I think we should just bite away at this issue bit by bit. > > I guess this really falls into the "new feature" category, as it's not > possible with OSG today on GL1/2 to mix FFP with app shaders. Therefore not > a requirement for OSG FFP-emulator shaders to mix with app shaders. But > definitely something to work towards.
I had original thought that we should try to tackle these "new features" at part of the adding GLES 2.0 + GL3 support, but now have moved to the much more modest and achievable goal of just supporting these new API's, and not trying to be too clever. > I think there are always going to be some developers that "just want OSG to > do everything" for them, without having to think too much about it, and they > will make heavy use of OSG FFP-emulator shaders. But there are also > developers that want full control, more direct access to the hardware, with > OSG used primarily for structure. Their numbers will grow as the paradigm > shift away form an FFP mentality continues. As long as OSG can serve both > groups' needs in an elegant manner that does not inhibit performance, the > community will be happy. Coding with home made shaders is really effective for achieving specific effects, far easier than justing to use the old fixed function pipeline - it's a real joy in fact having so much freedom. However, move away for specific effects and try to control the state in a more general purpose way as we often do with the scene graph - if you ever use a StateSet above a Drawable leaf then your are in the realm of composing state that the fixed function pipeline does so well, this is where shaders are weak right now. So there is this shader composition issue that we need to address. There is also the issue of how loaders deal with the scene graphs - you still want to load a model and have it look correct w.r.t how the modeler created it in their modeling app. Practically all of the plugins just load fixed function pipeline state, so in the GLES2 and GL3 realms what do we do? Forcing this to end users to deal with is rather shying away from the our job as scene graph developers. I don't have the answers to all this... all I can say is we still short of scene graph nirvana and will be for some while. This doesn't mean we can't do fun stuff right now though :-) Robert. _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
