RE: clarify the geoset question

New Message Reply Date view Thread view Subject view Author view

wrvo (WRVO++at++chevron.com)
Sat, 2 May 1998 13:07:37 -0700

I had a problem similar to this. I too was updating the geoset in one geode.
But it would only appear when another geode was added to the group. When
that second geode was removed, so did the contents of the first geode. It
was flashing too.

Here are two things that I found was happening:
1) the second geode contained a small cube that was placed on the screen at
the position of the cursor after an isect. I forgot to set the isect mask,
which defaults to 0xffffffff which means it isect with everything. When it
was not drawn, it isected with what it was supposed to and drew the cube.
Then it isected with the cube, but it wasn't the right things, so it removed
the small cube. Result was flashing of the geometry every other frame.

2) the changed geometry was not being drawn because I did not update the
bounding box and in particular the isect cache info. You need to call
setBound and also to reset the cache. I didn't have luck turning off the
cache and you probably don't want to. I did a curmask =
getIsectMask(PFTRAV_ISECT) followed by a
setIsectMask(PFTRAV_ISECT,curmask,....). Now the geometry is drawn and it
doesn't flash.
Hopes this helps.

Bill Volz

> -----Original Message-----
> From: Eddy Kuo [SMTP:ekuo++at++ait.nrl.navy.mil]
> Sent: Friday, May 01, 1998 4:38 PM
> To: info-performer++at++sgi.com
> Subject: clearify the geoset question
>
> Hello:
>
> I am trying to display a changing geoset into four channels
> each with different view. I did use a geode to wrap around
> the geoset.
>
> I put a channel->clear() in my draw callback (otherwise,
> old geometry will no get erase)
> The result is the image keep flashing as if I didn't have
> any double buffering. This flashing appear even when I
> take out the channel->clear in the draw callback.
>
> appreciate for any advice
>
> Ed.
>
> -------------------------------------------------------------------
> Eddy Kuo work phone: 202-767-6025
> Virtual Reality Lab home phone: 703-893-2553
> Naval Research Lab http://www.cis.ohio-state.edu/~ekuo
> -------------------------------------------------------------------
>
> =======================================================================
> List Archives, FAQ, FTP: http://www.sgi.com/Technology/Performer/
> Submissions: info-performer++at++sgi.com
> Admin. requests: info-performer-request++at++sgi.com
=======================================================================
List Archives, FAQ, FTP: http://www.sgi.com/Technology/Performer/
            Submissions: info-performer++at++sgi.com
        Admin. requests: info-performer-request++at++sgi.com

New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:57:21 PDT

This message has been cleansed for anti-spam protection. Replace '++at++' in any mail addresses with the '@' symbol.