Angus Dorbie (dorbie++at++bitch.reading.sgi.com)
Sat, 15 Mar 1997 04:06:36 +0000
Perhaps the problem lies with some performer assumptions about the
contents of your transformations for optimization purposes.
Investigate using pfDCS::setMatType
Cheers,Angus.
On Mar 14, 2:11pm, Dewey Anderson wrote:
> Subject: Perf eoe 2.0.3 vs Perf 2.0
>
> We developed our product with Performer 2.0 and run it on Indy, Impact and
Onyx
> using IRIX 5.3 with no problem. But we've noticed a problem when running it
on
> the O2 that we've tracked down to being a difference between Performer eoe
> versions. It appears that the O2 ships with Performer 2.0.3 and if we
replace
> that with 2.0 the problem goes away.
>
> Is anybody aware of some important difference between the two? Is there some
> patch we need to have? Or are we going to have to recompile with Performer
> 2.0.3 to run on systems with that eoe?
>
> DETAILS OF THE PROBLEM:
>
> It LOOKS like a perspective error in the X direction only. We draw 2D shapes
> in our window using OpenGL. Then we texture map that drawing onto a
rectangle
> in Performer and then draw it with Performer. We size the rectangle and
> calculate the FOV and viewMatrix in such a way as to keep the Performer
drawing
> the same size as its OpenGL counterpart when the rectangle is place at Z=0.
> (We use a coordinate system where the screen is the XY plane.) The result
is
> that you can't tell the difference between the OpenGL drawing and the
Performer
> version.
>
> I have a lot of faith in these calculations because we've been using them for
> so long on the Indy, Impact & Onyx.
>
> When run on the O2, the textured rectangle appears too wide, scaled out from
> the center of the screen. A small rectangle to the left appears too far
left.
> A small rectangle to the right appears too far right. A rectangle
straddling
> the middle of the screen appears too wide. It's almost as if the perspective
> calculation is making the rectangle appear TOO CLOSE in Performer. But this
> only happens in the X direction. If it were really a distance error, I'd
> expect the rectangle to be displaced vertically as well.
>
> The O2 details are:
>
> IRIX 6.3 for O2 including R10000, version 12161207.
>
> CRM graphics revision C.
>
>
>
> Dewey Anderson
> dewey++at++evt.com
> Evolving Video Technologies
>
>
>
>
>
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>-- End of excerpt from Dewey Anderson
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