From: Brian Furtaw (brian++at++sgi.com)
Date: 04/12/2000 04:19:36
I have seen this CAVE problem with text strings rendered by Performer,
are you having this problem with pfText nodes? I suggested to the
developer with the problem that first they turn off culling for those
nodes to prove that it is in fact a culling problem. Then if that works
check to see if the bounding volumes are DYNAMIC and not STATIC on the
pfText nodes. Finally make sure the bounding volumes are large enough by
experimenting with there size.
Brian
Bram Stolk wrote:
>
> Angus Dorbie wrote:
> >
> > Is it culled for a frame or two or is it the error permanent? I'm
> > guessing there may be a transport delay for one set of data and not the
> > other when the new info gets propagated to the cull process. A bit
> > speculative at this stage.
>
> The error is semi-permanent:
> It depends on the camera position (in my case: the pos of the
> tracking sensor on the VR glasses).
>
> If I move at least a meter away from the object, no erroneous culling
> occurs.
>
> If I move in closer to the object, at, let's say half a meter
> (real life CAVE dimensions), some cave walls cull the object.
> E.g. you see the object on the front projection, but not on the
> floor projection.
>
> Maybe Performer thinks the object lies outside the viewing frustum?
> After all, the viewing fustrum depends on camera position. And I assume
> Performer does frustum clipping, like most renderers.
>
> Also, I have a feeling that the more I move the vertices from
> their original positions, the worse the culling problem gets, which
> of course, sounds not that strange.
>
> I will try your suggestion of a huge bounding volume.
>
> Bram
>
> --
> ------------------------------------------------------------------------------
> Bram Stolk, VR Specialist.
> SARA Academic Computing Services Amsterdam, PO Box 94613, 1090 GP AMSTERDAM
> email: bram++at++sara.nl Phone +31-20-5923059 Fax +31-20-6683167
>
> "I heard if you play the NT-4.0-CD backwards, you get a satanic message."
> "Thats nothing, if you play it forward, it installs NT-4.0"
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