Re: Optimising frame rate.

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Inge Henriksen (inge++at++autosim.no)
Fri, 30 May 1997 15:08:05 +0200

Simon Dimaio wrote:
>
> Hi
>
> This is a question regarding graphics performance. I have written a
> relatively small visual simulation on an old PowerSeries system with 2
> processors (R2000A/R3000) and VGX graphics, which is to be ported to an O2
> with an R5000.
>
> Channel statistics (Powerseries) show the following process times:
>
> Application = 4.6ms
> Cull = 4ms
> Draw = 40ms
>
> Yet the total frame time is reported as 75ms.
>
> After the addition of some "on the fly" geometry (Geode), the process
> times become.
>
> Application = 4.6ms
> Cull = 11ms
> Draw = 60ms
>
> Total frame time = 120ms!
>
> On the Powerseries, locked at 60Hz, the graphics looks reasonable. The O2
> is not capable of locking the frame rate and the simulation becomes
> extremely sluggish.
>
> Why is the frame time so much longer than the sum of APP+CULL+DRAW?
> Surely, in APPCULL_DRAW multiprocess mode, my frame time should be more
> like 70ms?
>
> I know that this is a tricky question to answer without seeing the code,
> but how can I optimise my simulation? I have used backface culling
> wherever possible, have flattened the scene tree and have put all the
> non-latency critical simulation updates after pfFrame().

For optimization of your app. you could look at chapter 13;Performance
tuning and Debugging, in the IRIS Performer programming guide. What also
about using LOD's ???

>
> Thanks for your time.
>
> Regards
> Simon Dimaio
>
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-- 


Greetings


----------------------------
Inge Eivind Henriksen
Autosim A.S
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E-mail: <inge++at++autosim.no>
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