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RE: [x3d-public] Shaders and Triangles: was dedicated working-group focus on X3D interoperability



Hi, Dave --

Bad news! Don Brutzman just let us know that the publisher has postponed
publication for a couple of months :^(

  -- Dick

/***************************************************
* Richard F. Puk, Ph.D., President
* Intelligraphics Incorporated
* 7644 Cortina Court
* Carlsbad, CA  92009-8206
* Tel: +1-760-753-9027
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> -----Original Message-----
> From: Dave A [mailto:dave.arendash@corp.manyone.net] 
> Sent: Tuesday, December 26, 2006 2:23 PM
> To: Richard F. Puk
> Cc: 'Holger Grahn'; 'John A. Stewart'; 'X3D Graphics public 
> mailing list'; 'Web3D Consortium Members'
> Subject: Re: [x3d-public] Shaders and Triangles: was 
> dedicated working-group focus on X3D interoperability
> 
> Sweeeeeeet
> 
> Dave A
> 
> Richard F. Puk wrote:
> > Hi, Dave --
> > 
> > What is missing is tutorial material that explains things 
> in "content 
> > author"-speak. Fortunately, this is about to change. The 
> new Daly and 
> > Brutzman book will be out in about another month.
> > 
> >   -- Dick
> > 
> > /***************************************************
> > * Richard F. Puk, Ph.D., President
> > * Intelligraphics Incorporated
> > * 7644 Cortina Court
> > * Carlsbad, CA  92009-8206
> > * Tel: +1-760-753-9027
> > * E-Mail: puk@igraphics.com
> > * WWW:  http://www.igraphics.com/
> > \***************************************************
> > 
> >  
> > 
> >> -----Original Message-----
> >> From: owner-x3d-public@web3d.org
> >> [mailto:owner-x3d-public@web3d.org] On Behalf Of Dave A
> >> Sent: Wednesday, December 20, 2006 4:10 PM
> >> To: Holger Grahn
> >> Cc: John A. Stewart; X3D Graphics public mailing list; Web3D 
> >> Consortium Members
> >> Subject: Re: [x3d-public] Shaders and Triangles: was dedicated 
> >> working-group focus on X3D interoperability
> >>
> >> With this and other threads going around, it seems to me that the 
> >> question being asked is: for whom should X3D be easy for:
> >> browser/plugin programmers, or content authors.  My vote: 
> >> content authors. Unfortunately, the spec has largely been 
> driven by 
> >> browser programmers. This IMHO is why X3D has been problematic.
> >>
> >> Dave a
> >>
> >> Holger Grahn wrote:
> >>>  
> >>> Hi John
> >>>  
> >>> Regarding the Triangle nodes I agree that X3D has sometimes
> >> a bit of a
> >>> node bloat philosophy.
> >>>  
> >>> The IndexedFaceSet could represent handle it all.
> >>>  
> >>> On the other hand IFS in its generic form with per face 
> attributes, 
> >>> creaseAngle and seperate index list into attributes array
> >> doesn't  fit
> >>> the Open GL or Directx layout.
> >>> To render an IFS, one need to reformat/copy the data to flattened 
> >>> array structures.
> >>>  
> >>> The Triangle Set nodes are more constrained, they are
> >> fitting better
> >>> direct the OpenGL geometry mapping.
> >>> But  for DirectX9 requireing the interleaving of all
> >> attributes of a
> >>> vertex into one structure, they don't help much.
> >>>  
> >>> Hardware Shaders so far operate indepentently on vertices
> >> and pixel /
> >>> fragments, they can work on all primitives, I don't see
> >> Justins point
> >>> here, beside there might be differences how 
> implementations compute 
> >>> normals etc.
> >>>  
> >>> This changes with DirectX 10 adding geometry shader
> >> capability where
> >>> the actual input triangle structure is important.
> >>> Unfortunately in DirectX10 you always need to implement all
> >> appearance
> >>> using a shader, so the classical OpenGL 
> >>> lighting/material/texture/multitexture/fog
> >>>  model has been completly removed.
> >>>  
> >>> Greetings
> >>>  
> >>> Holger
> >>>  
> >>>  
> >>>  
> >>>  
> >>>  
> >>> ----- Original Message -----
> >>>
> >>>     *From:* John A. Stewart <mailto:alex.stewart@crc.ca>
> >>>     *To:* Justin Couch <mailto:justin@vlc.com.au>
> >>>     *Cc:* X3D Graphics public mailing list
> >> <mailto:x3d-public@web3d.org>
> >>>     ; Web3D Consortium Members <mailto:consortium@web3d.org>
> >>>     *Sent:* Wednesday, December 20, 2006 9:10 PM
> >>>     *Subject:* [x3d-public] Shaders and Triangles: was dedicated
> >>>     working-group focus on X3D interoperability
> >>>
> >>>     Justin;
> >>>
> >>>     Throwing in some more canadian pennies in the bowl;
> >>>
> >>>>     I'll go one step further. It's impossible to use
> >> Shaders without
> >>>>     the Triangle* nodes. Shaders require direct knowledge
> >> of the exact
> >>>>     geometry structure coming at them as well as precise
> >> control over
> >>>>     every aspect of the incoming geometry in order to
> >> work. Remove the
> >>>>     Triangle nodes and you must also remove Shaders too 
> as they're
> >>>>     pointless without them.
> >>>     We still don't need the *Triangle nodes for shaders. What the
> >>>     browser would
> >>>     need to recognize in your example, is that it should
> >> *not* optimize,
> >>>     and feed
> >>>     the triangles as encountered.  *that* mapping can be
> >> specified, and
> >>>     the browser
> >>>     certainly would know if a Shader was present, or not. 
> >>>
> >>>     While shaders are certainly cool, and my GPUGems books
> >> reside within an
> >>>     elbows reach of me, I doubt whether many on this list
> >> would choose
> >>>     to, um,
> >>>     teach shader programming in high school, for instance.
> >>>
> >>>     Shaders are neat, and have their place, but, at the
> >> moment, their
> >>>     application
> >>>     is rather specialized. 
> >>>
> >>>      
> >> --------------------------------------------------------------
> >> -----------
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> >>
> > 
> 

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