Steve Baker (sbaker++at++link.com)
Thu, 18 Sep 1997 08:52:22 -0500 (CDT)
> Hi,
> Performer offers several types of transparency ... can I define
> different types of
> transparency for different objects in one scene or is there only one
> type of
> transparency in one scene effective ?
> Is PFTR_NO_OCCLUDE faster ?
Yes, you can mix transparency types (just set it up in the pfGeoState using
gstate->setMode(PFSTATE_TRANSPARENCY, PFTR_BLEND_ALPHA) or
gstate->setMode(PFSTATE_TRANSPARENCY, PFTR_MS_ALPHA) or whatever you need).
Bear in mind that PFTR_MS_ALPHA only works on machines with multisampling
(ie don't try it on an O2!)
PFTR_NO_OCCLUDE doesn't seem to be measurably faster - although it avoids
the write to the depth buffer - so I suppose it might be fractionally
faster on very large polygons. These is a cost to turning it on and off,
so I suppose there is a risk that it might even slow things down a tad if
you have lots of small PFTR_NO_OCCLUDE polygons mixed up with other
geometry.
Steve Baker 817-619-8776 (Vox/Vox-Mail)
Hughes Training Inc. 817-619-4028 (Fax)
2200 Arlington Downs Road SBaker++at++link.com (eMail)
Arlington, Texas. TX 76005-6171 SJBaker1++at++airmail.net (Personal eMail)
http://www.hti.com http://web2.airmail.net/sjbaker1 (personal)
** Beware of Geeks bearing GIF's. **
=======================================================================
List Archives, FAQ, FTP: http://www.sgi.com/Technology/Performer/
Submissions: info-performer++at++sgi.com
Admin. requests: info-performer-request++at++sgi.com
This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:55:57 PDT