Re: Infinite Reality, Colour matrix and pfTexEnv Component

New Message Reply Date view Thread view Subject view Author view

Graham Jones (graham.jones++at++sharp.co.uk)
Wed, 22 Jan 1997 10:02:53 +0000


Thanks to those who replied to my question (Ran, Brian and Angus)

Ran Yakir wrote:
> Color matrix (and also colour matrix) can be applied to texture loads
> on InfiniteReality, Impact and O2. On RE, RE2 and VTX it is applied
> only to pixel transfers (glCopyPixels, glDrawPixels).

Would I be right in thinking that, on InfiniteReality, the colour matrix
is not applied when an object is rendered with a texture, but only when
the texture is sent to the hardware then?

So I wouldn't be able to render the same object three times with three
different colour matrices without downloading the texture three times
(I'm trying to avoid all that data flying around the place).

> > I wrote originally:
> > 2) Performer question - the pfTexEnv::setComponent call allows one
> > component of an RGBA texture to be selected and used as a single
> > component intensity texture.

Ran Yakir wrote:
> The setComponent call is valid only in IrisGL on RE2. On all OpenGL
> machines, interleaved textures are supported through the
> GL_DUAL_TEXTURE and GL_QUAD_TEXTURE parameters in OpenGL, and not
> through the texture environment.

So you are saying I will need to resort to using the OpenGL calls after
applying my Performer texture, as Angus suggested.

I'll have a go but I might have a few more questions if it doesn't come
off!

Thanks for all your help.

Graham.

-- 
Sharp Laboratories of Europe,         Phone: +44-(0)1865-747711
Oxford Science Park,                  Fax:   +44-(0)1865-714217
Oxford, OX4 4GA
England                               Graham.Jones++at++sharp.co.uk
=======================================================================
List Archives, FAQ, FTP:  http://www.sgi.com/Technology/Performer/
            Submissions:  info-performer++at++sgi.com
        Admin. requests:  info-performer-request++at++sgi.com

New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:54:25 PDT

This message has been cleansed for anti-spam protection. Replace '++at++' in any mail addresses with the '@' symbol.