From: Angus Dorbie (dorbie++at++sgi.com)
Date: 11/14/2000 18:30:10
You are not alone,
there seems to be an issue with the display list ordering of operations
inserted into the display list in cull callback functions with respect
to the nodes the callbacks are attached to. This is what
PFN_CULL_SORT_CONTAINED is supposed to resolve.
We were confident that we had tracked it down to pfChanBinSort modes vs
pfChanTravMode sorting and managed to eliminate the problem under some
circumstances. Recent information has cast some doubt on this theory but
we're certain it was the source of the problem in some sample code we
had. This is currently high on my list of things to be investigated. I
am very interested in any results you get from adjusting the values of:
pfChanBinSort(chan, PFSORT_OPAQUE_BIN, PFSORT_NO_SORT, NULL);
pfChanTravMode(chan, PFTRAV_CULL, PFCULL_VIEW|PFCULL_SORT);
Please get back to me with any feedback on your success or otherwise
with this approach. Try a few values for the sort modes and let me know
please.
If the above fails the advice I'm offering is to put the LOD offset
calls between custom user created draw bins and place the geometry into
these cliptexture LOD bins by range. This way there is no question of
the callbacks being in the right place and the there is the added bonus
of the geometry being consolidated into bins sorted by range eliminating
node callbacks and redundant offset calls.
Cheers,ANgus.
phowe++at++csc.com.au wrote:
>
> Hi,
>
> I'm continuing to have problems using channel bins. This time the problem
> is affecting our cliptextured geometry. What is happening is when we
> change the order of the OPAQUE bin so it is not the first bin drawn,
> the cliptextured geometry close to the eye is using a much lower resolution
> texture. We believe the problem may be associated with the fact that we
> are using PFN_CULL_SORT_CONTAINED mode on pfNodes togethor
> with preCull functions to set cliptexture parameters. I don't understand
> what the problem with this may be though. I'm also curious to know what
> the sortType PFSORT_QUICK does, which appears to be the sortType
> of the OPAQUE BIN, it does not appear in the man pages on our system.
> I'm not really expecting an answer, but I shall remain hopefully for any
> assistance.
>
> Thanks for any help.
>
> Peter Howe.
>
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