re: Multiple channels

New Message Reply Date view Thread view Subject view Author view

Michael T. Jones (mtj++at++babar.asd.sgi.com)
Tue, 13 Aug 1996 06:26:19 -0700


Ran Yakir wrote:

:Is there a substantial overhead in having multiple channels,
:occupying the same viewport, drawing multiple passes of the
:database ?

It causes more work, in that each channel gets traversed in the
cull, whereas calling pfDraw() multiple times causes the same
pfDispList built by the cull to be reused. Since most applications
are not cull-limited (6-chan and 8-chan apps like MagicEdge are
common exceptions) then you probably won't see any performance
difference on an MP APP_CULL_DRAW system.

By the way, if you want to do multipass rendering where different
types of geometry are handled separately (diffuse, emissive, and
so on) check out the pfGeoSet PassFilter and DrawBin functions.

Michael

Be seeing you, Phone:415.933.1455 Fax:415.965.2658 M/S:8U-590
Michael T. Jones Silicon Graphics, Advanced Systems Division
mtj++at++sgi.com 2011 N. Shoreline Blvd., Mtn. View, CA 94039-7311
                    "Du musst Amboss oder Hammer sein" -- Goethe

=======================================================================
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 - 17:53:21 PDT

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