Good summary, Gordon. I agree, with much of the current OSG dedicated to managing a fixed function pipeline, starting from a clean slate would be the way to go. I'd hate to see the OSG community try to maintain the existing API given its such a poor fit for OpenGL 3.
As Robert points out, this will be hard for existing OSG (and OpenGL) users. But these users are the ones who will ultimately decide when the move takes place. OpenGL 2 drivers should be available for a while, but eventually there will be an ISV shift towards OpenGL 3, and soon thereafter OpenGL 2 drivers will disappear. (This will not be unlike the PEX/PHIGS/GL shift to OpenGL 1.x in the mid-1990s.) My main concern with moving forward with a new clean slate is that we need to see ISV support for that BEFORE the OpenGL 2 drivers go away, so that there is sufficient time and funding to develop a new OSG that integrates with OpenGL 3. There will be little movement in OSG towards OpenGL 3 without funding to back that effort. To that end, I'd like to hear from any companies that are interested in seeing a new OSG for OpenGL 3. Paul Martz Skew Matrix Software LLC http://www.skew-matrix.com 303 859 9466 > Hi Y'all > > Having attended the SIGGRAPH OpenGL Bof the first thing you > have to realize about OpenGL 3.0 is that it is NOT an > extension to 2.x it's a very new beast with some cross over > but the changes to OGL3.0 are very very intrusive to the way > OSG or any Scenegraph works or even OpenGL program, and the > scenegraph that supports OGL3.0 will be a very different > beast to what we have today > > OGL 3.0 is not backwards compatible with previous versions, > > >From what I have seen and what I understand, IMO the OSG > version that > >will > embrace OGl3.0 will be a very new Scenegraph, the changes are > simply too many and fundamental to the way things currently > work. If you we don't approach this in a new clean slate way > then we will spend most of our time, going down the road of > this is how it used to work and we will mimic that and spend > most of our time trying to replace OGL2x in OGL3.0 > > Once the spec is finalized hopefully shortly and folks get a > read and start to see what was talked about at the BOF and > how fundamentally different OpenGL 3.0 is it will be much > clearer on why any Scenegraph that supports Opengl3.0 will be > different > > Simple things like glbegin() and glEnd() are dead, no clients > side array's any more, only 2 draw Functions, many uniforms > currently supported in Shaders are gone, a new program stage > placed between Vertex and Pixel stages, many things made immutable > > Basically we have a new language to learn > > You can see many of the bullet points ar > http://www.khronos.org/library/detail/siggraph_2007_opengl_bir ds_of_a_feathe > r_bof_presentation/ > > > Just my 2 cents > > __________________________________________________________ > Gordon Tomlinson > > Email : [EMAIL PROTECTED] > YIM/AIM : gordon3dBrit > MSN IM : [EMAIL PROTECTED] > Website : www.vis-sim.com www.gordontomlinson.com > > __________________________________________________________ > "Self defence is not a function of learning tricks but is a > function of how quickly and intensely one can arouse one's > instinct for survival" > -Master Tambo Tetsura > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf > Of Robert Osfield > Sent: Friday, August 10, 2007 5:51 AM > To: [email protected] > Subject: Re: [osg-users] OpenGL 3 announced > > On 8/10/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > someone wanted to know when will osg support opengl 3? yes > i know the > > specs aren't even finalized, but i want to give the guy an > answer and > > not let him pass in a forum with foul arguments against osg, > > especially not at heise.de. ;) > > There is no way I can given a specific time to support 3.0, > since it's not finalised nor any implementations available. > I can say that I'm a committed supporter of OpenGL in general > and the path the ARB are taking to OpenGL 3.0, so I'm > following developments closely with the intention of supporting it. > > There are some major technical issues to resolve w.r.t how we > go about integration. In some ways a clean slate, OSG 3.0 > mapping to OGL 3.0 would be ideal, with the both general > hardware, OSG and OGL all becoming ever more multi-threaded, > and with new object models that perhaps suit a different > means of encapsulation at the scene graph end. With a clean > slate OSG 3.0/OGL3.0 would be trim down the scene graph > substantially too. Perhaps also an opportunity to improve > the scriptability of the scene graph too. > > A clean slate approach is not good for existing users, not > good for getting out version of the OSG with OGL3.0 in a > timely manner. Right now we need to support the latest OGL > extensions, then look at how one might integrate OGL3.0 > features in a relative non intrusive way. The OSG has > already coped surprisingly with evolution from OGL1.1 to > OGL2.1, so we can probably handle OGL3.0 too given a > willingness to refactor parts that need it. Maintaining > backwards compatibility with older versions of OGL is what > will complicate things, I see its part of the OSG's role to > hide this complexity of managing multiple OGL versions so I'd > like to see a graceful way of handling the new object model. > > Robert. > _______________________________________________ > 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-opensce negraph.org _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
