Steve Baker (sbaker++at++link.com)
Thu, 20 Nov 1997 10:02:15 -0600 (CST)
> Hi Michael
>
> Michael T. Jones wrote:
> > 2. disable geometric cull testing for that node **AND ALL
> > OF IT'S PARENTS UP TO THE ROOT**. this is necessarially
> > so since the cull testing is hierarchical in nature.
>
> Just curious about why Steve used PFTRAV_CONT and not PFTRAV_PRUNE to
> alter the behaviour of the cull traversal. Otherwise his answer to the
> original posting was very helpful, as per usual.
The return result wasn't what did the altering - it was the pfCullResult
that did that!
> The reason I asked was because the node in question may be a group node
> representing an assembly of components. If so, there will be a lot of
> child nodes to leave alone as well.
Well you didn't say that you wanted all of those kept as well!
Simply change the pfCUllResult on the node you must keep (with all of
it's children) to return PFIS_MAYBE | PFIS_TRUE | PFIS_ALL_IN
and CULL will just blindly assume that everything below the magic node
is inside the view frustum.
BUT DO NOT RETURN THIS RESULT ON THE PARENTS OF THE MAGIC NODE!!
> I wasn't too sure what would happen
> in that case and so thought PFTRAV_PRUNE might have been better than
> writing a node traversal function for each child as well.
If you do what I suggest above then you won't need node traversal functions
for each child of the magic node.
Steve Baker 817-619-8776 (Vox/Vox-Mail)
Hughes Training Inc. 817-619-4028 (Fax)
2200 Arlington Downs Road SBaker++at++link.com (eMail)
Arlington, Texas. TX 76005-6171 SJBaker1++at++airmail.net (Personal eMail)
http://www.hti.com http://web2.airmail.net/sjbaker1 (personal)
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