Dewey Anderson (dewey++at++evt.com)
Fri, 14 Mar 1997 14:11:16 -0800
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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