Sharon Clay (src++at++rose.engr.sgi.com)
Thu, 23 Apr 1998 22:47:58 -0700
I'm glad this has come up and that folks are asking the
these specific questions so we get a chance to answer them in a
targeted fashion. I'll try to address some of the questions raised
in the recent postings (some of this is just redundant and seconding
what Angus has already said).
+>---- On Apr 23, 9:11am, Brian Corrie wrote:
> Subject: Re: Performer at ITEC
->
->
->I, and I am sure many others, would be very interested in hearing about SGI's
->roadmap for Performer, Optimizer, OpenGL, OpenGL++, etc., with respect to
->Fahrenheit. Is it possible that some details could be posted to this list
->(from you or someone else at SGI) as well. We were hoping to see an initial
->release of OpenGL++ in the next couple of months, but according to the OpenGL
We have the high level in every presentation slide set we give.
A bit of this in our I/ITSEC 97 slides (on the web site).
http://www.sgi.com/Technology/Performer/technical.html
OpenGL is still going strong and 1.2 was just released! In brief,
the SGI OpenGL++ effort has now transitioned into Fahrenheit Scene
Graph (FSG). FSG will run on OpenGL, D3D, and Fahrenheit Low
Level(FLL) when that exists. FSG will be cross-platform and will be
shipped with at least Windows and IRIX.
The next major version of Performer (3.0) will use Fahreneit Scene
Graph. Since the pfSceneGraph and basic MP model will largely
transition into FSG, we have a chance to re-evaluate what
Performer3.0 should exactly be and how it can best serve our Visual
Simulation customers. Future vertical market toolkits from SGI will
all be based on FSG so that they use the same Scene Graph and MP
model. But, the rest of that is for Chris's talk at ITEC and we'll
put his slides on the web site after the show.
->ARB meeting minutes from March 9-10
->
->(http://www.opengl.org/ARB/Notes/Meeting1.2/meeting_note_10-03-98.html)
->
->Kurt Akeley (at least so the minutes say, I wasn't there...) says that "SGI
->will no longer be able to push OpenGL++ (though they have no objection to
->others picking up the work). Resources are committed to work with Microsoft
->and HP on the scene graph and large model visualization APIs." Does this mean
->that we will be waiting for the Fahrenheit scene graph as opposed to OpenGL++?
As Angus indicated, yes. The SGI and Microsoft parts of the OpenGL++
effort have transitioned into FSG and FSG is derrived directly from
the spec and source code base that we had for OGL++. Some solid
improvements have been made that will produce much better
extensibility on NT platforms but that is for another discussion. In
general, we have made a lot of progress on the entire thing since
last Dec.
->
->If I was there, I would be asking the above question 8-) We have been
->developing some software under the assumption that OpenGL++ would be available
->sometime near the middle of this year. This has a fairly significant impact on
->some our plans and I have not been able to find out any information through
->our normal SGI channels.
The most detailed we ever got was in summer '97 hoping for a Beta in
summer '98. As we mentioned then, that was a very tentative outlook
because we were (and are) talking about a 1.0 type of release here.
The schedule at this point probably is not all that different than it
otherwise would have been. As announced at the Fahrenheit launch, we
are trying for a released product mid-98. We'll do a beta before
that, and limited alpha exposure before that. I'd say the move to
Fahrenheit made us slip a bit but not significantly and the
additional changes that have been incurred feel good. We are able to
be a lot more directed and focused now so that might also make up for
a little of the lost time :-)
I'd be interested to hear more privately about how your plans are
affected so I can be better informed about how these changes are
impacting people. Naively, I'd assume your plans had to allow some
flexibility around OGL++ and hopefully we haven't disrupted the
waters too much by doing this with Fahrenheit. While I can't go into
all of the details at this stage, I can definitely say that our
general direction and goals have not changed.
+>---- On Apr 23, 8:39am, Steve Baker wrote:
> Subject: Re: Performer at ITEC
->
->I wonder if anyone would be interested in a cooperative 'freeware' Mesa++ (ie
->
->I have an OpenGL++ spec (probably out of date now) - but I can't do
->anything with it since it was provided under NDA.
Yes, it was.
->I have been using Performer (another OpenGL scene graph API) under IRIX,
->it would be nice to have a suitably Open scenegraph API to replace it on
->Windoze and Linux platforms.
If the trouble is the fear that needed OS platforms aren't supported,
or that certain features aren't available in the OSs that we are
covering then SGI and Microsoft would like to hear about that and
why they are needed.
If what you really have is detailed questions on licensing for other
OS platforms, then it might be better to pose those to Microsoft or at
least a forum where they are listening.
->If anyone at SGI is listening and would be prepared to release a non-NDA
->OpenGL++ spec, I'm sure that would be interesting to many people on this
->list.
In truth, I don't think that last Dec. spec would provide much
insight for folks that have seen Performer and Inventor beyond
reassuring folks that we are still doing a Scene Graph. Since the
goal here is a pervasive standard, I'd hope that folks would use
Fahrenheit and not try to start up a separate effort now on something
old. SGI will only participate in one effort and honestly believe
what we have created with Fahrenheit is the right thing, both for ISV
and IHVs that want to be able to differentiate on top of and
underneath a ubiquitous API. I don't think multiple efforts is going
to help anyone at this point.
If what you want is programming hints for future directions, then be
assured that 1) we are trying to both forumulate and limit the
complexity of the transition path from our current products and 2)
will advertise a set of hints when relevant. It is really probably a
bit premature at this point and I don't think that superficial
"change pfLOD to xxLOD" type hints are really what you are looking for.
+>---- On Apr 23, 11:04am, Prakash Mahesh wrote:
->> Subject: Re: Performer at ITEC
->
->I guess this problem (not knowing what direction SGI on the whole is
->taking) is widespread among the SGI developers. We use Performer,
->Optimizer, plain OpenGL and many other libraries, and we have started
->supporting Windows/Solaris recently, but our main focus is still SGI.
->But the recent developments at SGI and more importantly the
->non-availability of information to developers is making things look
->unclear. Yes, I hope someone from SGI would openly make an (even
->unofficial) announcement on what their plans are.
I really need a more specific question here to know what you are
really asking. Our general direction has never changed, we have just
been looking for a way to get a set of APIs to be pervasive in the
industry and have them be APIs that are carefully constructed to
allow us (and other hardware vendors) to differentiate within the
same API. It will also help ISVs because then the burden of
customizing SW to run well on different platforms can be in large
part carried by the hardware vendors. This is what we have done with
OpenGL at the low level and at the scene graph level (for the SGI
product line) with Performer. This is what we (and others) will do
with Fahrenheit for a cross-plaform solution.
A couple of additional notes:
For more some current big picture or lengthy
essays, I'll point to some handy sites you might peruse:
General SGI Fahrenheit site: http://www.sgi.com/fahrenheit/
A recent good article from a talk by Kurt and Jay:
http://www.gamasutra.com/features/programming/19980410/fahrenheit_01.htm
I think this should address the basic questions that have come up.
We will give out more detailed technical information at a later stage
as it becomes appropriate.
I hope this helps and thanx for asking!
src & chris.
-----{-----{---++at++ -----{----{---++at++ -----{----{---++at++ -----{----{---++at++
Sharon Rose Clay - Silicon Graphics, Advanced Systems Dev.
src++at++sgi.com (650) 933 - 1002 FAX: (650) 965 - 2658 MS 8U-590
-----{-----{---++at++ -----{----{---++at++ -----{----{---++at++ -----{----{---++at++
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