Angus Dorbie (dorbie++at++bitch.reading.sgi.com)
Tue, 10 Dec 1996 12:48:18 +0000
Use the pfFrustum member function makePersp which allows you to
specify off axis projections. The viewing vector (hpr) is specified
as usual, don't try to specify the viewing vector relative to the
frustum, take a wholistic view;
thus:
(hpr)
.........|....._____________ frustum specified on plane
| / _ - defined by hpr vector and
| / _ - near clip distance for makePersp
| / _ -
| / _ -
|/-
o eye
The only thing you have to worry about is that the fog range & z is
specified along the viewing vector.
Cheers,
Angus.
On Dec 10, 11:31am, Guy Premont wrote:
> Subject: Off-axis camera
> Hi everyone,
>
> I'm having a difficulty that is not specifically from Performer, but I'm
> certain somebody here could help me. I'm fairly new to Performer (worked
> on it for about 6-8 months) so please forgive me if this is a stupid
> question! I'm working with Performer 2.0.
>
> I'm trying to setup a camera that can be off-axis; that is, the line
> from the eyepoint doesn't pass through the center of the image and it is
> not perpendicular to the image. My first idea was to create a frustum
> with pfMakePerspChan and then to offset the axis it with
> pfChanViewOffsets. However, this doesn't seem to work. Would there be a
> way to describe the frustum directly with a pfMatrix? I guess I can do
> it with GL calls but I have to be in the draw process, am I right?
>
> Thanks
>
> Guy Premont
>-- End of excerpt from Guy Premont
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