OpenGL Shading Language <-> RenderMan Shading Language

OpenGL Shading Language <-> RenderMan Shading Language

Post by Nicholas Y » Fri, 03 May 2002 12:53:26



Hi,

  Does anyone know if it is the intention for the OpenGL Shading
Language to be compatible with RenderMan Shading Language.

  I am developing an application in OpenGL which I plan to use OpenGL
Shading Language and output to RIB for rendering via a RenderMan
compliant renderer.

  I am hoping that the shader I write for OpenGL can be reuse for the
renderer.

Cheers
--
Nicholas Yue
http://www.geocities.com/nicholas_yue

 
 
 

OpenGL Shading Language <-> RenderMan Shading Language

Post by Will » Fri, 03 May 2002 13:49:58




>Hi,

>  Does anyone know if it is the intention for the OpenGL Shading
>Language to be compatible with RenderMan Shading Language.

I read through a crappy PDF about what 3D Labs wanted OpenGL 2.0 to be.  That
had programmable shading.  Are you talking about that?  Or, do you mean the
current implementations as defined by OGL extensions by Nvidia, and ATI?

Well, either way, no, they are not intended to be compatible.  Even the
proposed OGL 2.0 stuff is designed for real time systems, and is designed
differently from what we all know and love as SL.

Quote:>  I am developing an application in OpenGL which I plan to use OpenGL
>Shading Language and output to RIB for rendering via a RenderMan
>compliant renderer.

I'm still not 100% sure what you mean by OpenGL Shading language, but if you
are developing in it, you should probably have some sort of syntax guide,
specification, or something.  If so, write an OGL shader, and try it in your
favorite renderman renderer.

Quote:>  I am hoping that the shader I write for OpenGL can be reuse for the
>renderer.

The two are probably similar enough in design that there will be a pretty
straight forward way to take an OpenGL shader, and spit a roughly equivalent SL
file out the other end.  Most likely, the OpenGL shading system will be simpler
than SL, and have fewer features, so your shaders won't make full use of SL,
but will be fine for government work.

Quote:>Cheers
>--
>Nicholas Yue
>http://www.geocities.com/nicholas_yue

------------------
What good is knowledge if you can't torment others with it?   --Paul W. DeMone

 
 
 

OpenGL Shading Language <-> RenderMan Shading Language

Post by Simeo » Fri, 03 May 2002 14:00:08


I have heard some things saying that OpenGL 2.0 wants a higher level
programable shading language in the same spirit as the Renderman SL, and I
think that if they do it, whomever is creating the spec will take quite a
bit from the highly evolved, well designed, and time tested Renderman SL,
but I seriously doubt that they will be directly compatible.  If it is
compatible, the day of the realtime photosurealistic rendering will be so
much closer.


Quote:> Hi,

>   Does anyone know if it is the intention for the OpenGL Shading
> Language to be compatible with RenderMan Shading Language.

>   I am developing an application in OpenGL which I plan to use OpenGL
> Shading Language and output to RIB for rendering via a RenderMan
> compliant renderer.

>   I am hoping that the shader I write for OpenGL can be reuse for the
> renderer.

> Cheers
> --
> Nicholas Yue
> http://www.geocities.com/nicholas_yue

 
 
 

OpenGL Shading Language <-> RenderMan Shading Language

Post by Nicholas Y » Fri, 03 May 2002 23:28:14



> I have heard some things saying that OpenGL 2.0 wants a higher level
> programable shading language in the same spirit as the Renderman SL, and I

  Yes, that's the one I was reading about.

  Will check on 3DLabs/OpenGL-ARB to see if they have a language specification.

Cheers.
--
Nicholas Yue
http://www.geocities.com/nicholas_yue

 
 
 

OpenGL Shading Language <-> RenderMan Shading Language

Post by Felipe Esquive » Fri, 03 May 2002 23:54:14



Quote:> Hi,

>   Does anyone know if it is the intention for the OpenGL Shading
> Language to be compatible with RenderMan Shading Language.

What I understood about the OpenGL Shading Language from SGI last
SIGGRAPH
was you can use your all your RenderMan shading language code and
translate it to OpenGL
in some way, the most obvious is a direct API call. I also understand
these libraries
are available for Irix only. Here I want to confess something happened
to me regarding
this issue. When you don't speak in good english, some people doesnt
have enough
patience, the guy form SGI just replied yes to all my questions and told
me he will
send all the information later. I'm still waiting.

Please escuse me if this information in not clear enough or just doesn't
hit
the point correctly.

Felipe Esquivel

--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

 
 
 

OpenGL Shading Language <-> RenderMan Shading Language

Post by Marc Ola » Sat, 04 May 2002 03:55:06





>> Hi,

>>   Does anyone know if it is the intention for the OpenGL Shading
>> Language to be compatible with RenderMan Shading Language.

>What I understood about the OpenGL Shading Language from SGI last
>SIGGRAPH was you can use your all your RenderMan shading language
>code and translate it to OpenGL in some way, the most obvious is a
>direct API call. I also understand these libraries are available for
>Irix only. Here I want to confess something happened to me regarding
>this issue. When you don't speak in good english, some people doesnt
>have enough patience, the guy form SGI just replied yes to all my
>questions and told me he will send all the information later. I'm
>still waiting.

Which guy from SGI? I'm the tech-lead of SGI's OpenGL Shader and I
have no record of getting your email, either directly or through the

don't have your original questions, I'll do my best to guess what they
were and answer.

First, I think the original poster in this thread is interested in the
language for OpenGL 2.0, which is a different thing than the ISL
language that's part of SGI's OpenGL Shader. OpenGL 2.0 is a proposed
API and shading language for hardware that's not out yet, but that we
expect to see soon. Info on OpenGL 2.0 is available from 3DLabs at
    www.3dlabs.com/support/developer/ogl2

OpenGL Shader supports a simple shading language on current hardware.
Some info on it is available from SGI at
    www.sgi.com/software/shader/

OpenGL Shader is available as a free download for both IRIX and Linux,
but since it's designed to run on existing hardware its only
varying data type is fixed point (not float as in RenderMan) and
clamped to lie between 0 and 1. Given that restriction, it's
could be possible to translate an ISL shader to RenderMan. In
the general case it isn't possible to translate a RenderMan shader to
ISL. Contrast to OpenGL 2.0, which does assume we'll have hardware
support for per-pixel floating point data.

A third factor that might be introducing some confusion is that four
years ago we also built a full RenderMan implementation on top of a
software OpenGL (i.e. NO hardware acceleration) assuming pixel texture
(aka dependent texturing) and per-pixel floating point. We were able
to show that given those capabilities in your graphics hardware you
would be able to create an accelerated RenderMan (pre-DSO shadeops).
This RenderMan implementation and OpenGL Shader are NOT the same thing
-- similar underlying compilers, but different languages, different
target hardware and different capabilities. The RenderMan
implementation has been demonstrated at SIGGRAPH and is covered in the
same SIGGRAPH paper as OpenGL Shader.

To sum up:
- OpenGL 2.0:
    Uses OpenGL 2.0 Shading Language. Similar in capability to
    RenderMan, but not the same. Doesn't run on any current hardware.
    Some sample implementation source code is available from 3DLabs.
    Expect to run on future hardware.
- SGI's implementation of RenderMan on OpenGL:
    Uses RenderMan shading language. Doesn't run on any current
    hardware. Isn't released. We've no plans to release it.
- SGI's OpenGL Shader:
    Uses simplified shading language. Runs on current hardware.
    Released for IRIX and Linux.

Marc Olano

 
 
 

OpenGL Shading Language <-> RenderMan Shading Language

Post by Joshua D. Boy » Mon, 06 May 2002 08:09:20



> I read through a crappy PDF about what 3D Labs wanted OpenGL 2.0 to be.
> That had programmable shading.  Are you talking about that?  Or, do you
> mean the current implementations as defined by OGL extensions by Nvidia,
> and ATI?

> Well, either way, no, they are not intended to be compatible.  Even the
> proposed OGL 2.0 stuff is designed for real time systems, and is
> designed differently from what we all know and love as SL.

To what extent is the 3DLabs OGL 2.0 programmable shading taken from
SGI's OpenGL Shader (http://www.sgi.com/software/shader/)?  I heard that
worked pretty well, but all the SGIs I have access are running 6.4 (or
earlier) or don't have development tools.
 
 
 

OpenGL Shading Language <-> RenderMan Shading Language

Post by T. Burg » Mon, 13 May 2002 12:43:56


Right now OpenGL is up in the air when it comes to pixel and vertex hardware
shaders.  nVidia and ATI are each pushing their own standards.  I haven't
been following 3Dlabs recently but I heard they have a new part.

If you want to see what the near future direction for hardware shaders and
actual features, I hate to say it but you need to look at D3D and if you can
get it, information on the next version coming out.  It's been true for
three to four years now, hardware vendors design for D3D because that is
where the money is.  Higher end cards based on the part that just came out
and OpenGL support then follow.  Maybe 3Dlabs is different in that respect,
but in general I think the fact that D3D leads a bit in this area is true
for now.

T. Burge


Quote:> Hi,

>   Does anyone know if it is the intention for the OpenGL Shading
> Language to be compatible with RenderMan Shading Language.

>   I am developing an application in OpenGL which I plan to use OpenGL
> Shading Language and output to RIB for rendering via a RenderMan
> compliant renderer.

>   I am hoping that the shader I write for OpenGL can be reuse for the
> renderer.

> Cheers
> --
> Nicholas Yue
> http://www.geocities.com/nicholas_yue

 
 
 

OpenGL Shading Language <-> RenderMan Shading Language

Post by Peter R. Brinkle » Mon, 13 May 2002 12:59:09


Hi I could not just let this pass....

This article
(http://www.extremetech.com/print_article/0,3428,a=26271,00.asp) contain
some code snippets which are indicative of how the ogl 2.0 shading
language will look. As you will see the proposed ogl shading language is
not compatible with the renderman shading language, they are related so
hopefully we will see converters from rmsl to oglsl and vice versa.

You might want to consider not using D3D if you plan on making your
application portable. D3D does not work on *nix nor can I find any
indications of Microsoft having the intention to bring D3D to other
platforms than Windows. D3D is more advanced than the current version of
ogl, no doubt about that. The ogl 2.0 is hopefully going to change this.

Personally I have briefly looked over the D3D api but I have not used the
api myself as I mainly(solely) program my opengl applications for *nix.
The impression I got from the api was that the D3D api were a bit more
messy than the ogl equivalents. This was awhile ago and I have heard that
the api have improoved greatly since the last versions.

Many games today uses the D3D apis, a few uses opengl, most modelling
packages use ogl as far as I know.

Sincerely,
Peter


> Right now OpenGL is up in the air when it comes to pixel and vertex
> hardware shaders.  nVidia and ATI are each pushing their own standards.
> I haven't been following 3Dlabs recently but I heard they have a new
> part.

> If you want to see what the near future direction for hardware shaders
> and actual features, I hate to say it but you need to look at D3D and if
> you can get it, information on the next version coming out.  It's been
> true for three to four years now, hardware vendors design for D3D
> because that is where the money is.  Higher end cards based on the part
> that just came out and OpenGL support then follow.  Maybe 3Dlabs is
> different in that respect, but in general I think the fact that D3D
> leads a bit in this area is true for now.

> T. Burge



>> Hi,

>>   Does anyone know if it is the intention for the OpenGL Shading
>> Language to be compatible with RenderMan Shading Language.

>>   I am developing an application in OpenGL which I plan to use OpenGL
>> Shading Language and output to RIB for rendering via a RenderMan
>> compliant renderer.

>>   I am hoping that the shader I write for OpenGL can be reuse for the
>> renderer.

>> Cheers
>> --
>> Nicholas Yue
>> http://www.geocities.com/nicholas_yue

As always remove no.spam from email to reply directly.