From: Angus Dorbie (dorbie++at++sgi.com)
Date: 10/11/2000 19:24:03
No that is not what I said. It does depend on your definitions though.
This has been discussed at length already. See posts by Remi, mtj & me.
Database paging was common years before cliptexture. Paging does not
require clip texture and not all paging is clip texture. Clip texture is
one particularly elegant scheme. One of it's major advantages is it
decouples paging from geometry and state management. A single texture
object and no geometry subdivision is what makes it so useful in a scene
graph. Asside from LOD management on virtual textures due to hardware
limitations it is unfettered by resolution compromises or restrictions
on geometry
Cheers,Angus.
"Joseph R. Spann" wrote:
>
> Cool! So clip texturing is a software problem after all.
> So now that a year has gone by I'll ask again:
> How about software cliptexture support for Performer running on
> systems other than an Onyx? Especially linux!
> "I saw the Intrinsic Graphics people do 60Hz clipmapping on a PC..."
> I'd expect you could do as good as that.
> This is really critical for desktop to supercomputer product support.
> Cliptextures reduce the hardware burden so significantly it belongs on a PC.
>
> Pretty please:-)
>
> > -----Original Message-----
> > From: dorbie++at++sgi.com [mailto:dorbie++at++sgi.com]
> > Sent: Sunday, October 08, 2000 8:16 PM
> > To: Hui Li
> > Cc: info-performer++at++sgi.com
> > Subject: Re: An OpenGL Question
> >
> >
> > The progressive loading in OpenGL 1.1 is just glTexSubImage2D
> >
> > To do something like clip texturing, or even to exploit clip texture
> > capability where you have it requires quite complex and sophisticated
> > software to manage a texture database from disk to system memory and on
> > to graphics hardware. Even the requisite tweaks to graphics hardware
> > only make this a more elegant scheme, you still need good software. If
> > you want to do this in OpenGL yourself you'll have to create a database
> > of the right structure, load files from that database to memory based on
> > the paging requirement and download that to texture memory in a tightly
> > controlled way if you want anything close to good performance.
> >
> > CHeers,Angus.
> >
> > > Hui Li wrote:
> > >
> > > This is acurally an openGL question
> > >
> > > My application on PC using Opengl need serf large terrian with
> > > huge amount of texture, Cliptexture on Performer could do it
> > >
> > > but with openGL what should i do, i heard that with OpenGL1.1 or
> > > higher, it support progressive texture loading, can any body give
> > > me more clue?
> > >
> > > Hui
> >
> > --
> > For Performer+OpenGL tutorials http://www.dorbie.com/
> >
> > "In the middle of difficulty lies opportunity."
> > --Albert Einstein
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