Re: 2.1 PACKED ATTRS

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Marcus Barnes (marcus++at++multigen.com)
Wed, 3 Jul 1996 17:13:07 -0700

On Jul 4, 1:25pm, Nacho Sanz-Pastor. Computer Arts + Developments wrote:
> Subject: 2.1 PACKED ATTRS
> Hi all,
>
> Does anybody know if it's possible ( I guess it's not ) to use vertex arrays
> in 2.1 that only pack normals, texvertices and vertices, without the per
> vertex color field ?

Yes this is okay for pfGeoSet's. Just set the PFGS_COLOR4 attribute binding to
PFGS_OFF when creating geosets.

> Most of the objects we use have normals, texverts and coords but colors are
> used in only around 10% of the objects, so that seems a waste of host to gfx
> bandwith ...

Yes it is a waste of bandwidth. I believe Performer will be getting "smarter"
about immediate mode drawing wrt the current graphics state in a future release
(I haven't noticed it in 2.0 or 2.1). For instance, there is no reason to
download texCoords when texturing is disabled or to issue color commands for
lit geometry when pfMtlColorMode is PFMTL_CMODE_COLOR.

With OpenFlight V14.2 and later, you can create models without color. I have
added support for this practice in the upcoming release (R15.2) of the
OpenFlight loader (still in development).

Regards.

--
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