Liu Xiaoyan (liuxy++at++ihpc.nus.edu.sg)
Wed, 23 Dec 1998 17:25:21 +0800
In case you want to know the outcome.
I allocated the puffer with PRESERVED_CONTENTS_SGIX, and read the image
immediately after pfDraw, it works now. Maybe the cause is just as what Phil
says below: depth planes are clobbered. But, does this mean we should ALWAYS
use a preserved pbuffer?
Many thanks......
Phil Keslin wrote:
> When do you read the contents of the pbuffer? Did you allocate the
> pbuffer with PRESERVED_CONTENTS? If not, any process with an active GL
> context could force your pbuffer to get clobbered. On the OCTANE MXI and
> a display resolution of 1280x1024, your pbuffer will share depth with
> the front planes. It is possible that your depth planes are getting
> clobbered resulting in failure of the depth test. The contents of the
> pbuffer color buffers won't change in that instance.
>
> - Phil
> --
> Phil Keslin <philk++at++engr.sgi.com>
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Liu Xiaoyan Institute of High Performance Computing
Research Engineer National University of Singapore
Data Visualisation Group http://www.ihpc.nus.edu.sg Tel:(65)7709267
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This archive was generated by hypermail 2.0b2 on Wed Dec 23 1998 - 01:28:38 PST