From: Fred Dech (fred@cerulean.bvis.uic.edu)
Date: 05/16/2000 08:12:06
Don Burns wrote:
>
> > ok. let's say, for example, that i need to modify the color LUT dynamcally
> > from the computational process. is there a straightforward approach to
> > get the LUT parameters into the Performer node, so that this can be applied
> > to the OGLVolumizer?
>
> So, for whatever reason, we subclassed pfVolume as a pfGroup. I would have
> preferred it to be a pfGeode, but for some compelling reason, which I don't
> remember, we subclassed it as a pfGroup. You'll need to add the following
> method to the pfVolume class in pfVolume.h:
>
> pfGeode *getGeode( void ) { return geode; }
>
> You'll then need to create a pfColortable and add it to each of the geosets in
> the geode:
>
> pfColortable *ctable = new pfColortable;
>
> pfGeode *geode = vol->getGeode();
> for( int i = 0; i < geode->getNumGSets(); i++ )
> {
> pfGeoSet *gset = geode->getGSet( i );
> pfGeoState *gstate = gset->getGState();
> gstate->setMode( PFSTATE_ENCOLORTABLE, PF_ON );
> gstate->setAttr( PFSTATE_COLORTABLE, ctable );
> }
>
this sounds good. assuming it works, it provides a more Performer native
interface to the pfGroup volume than the previous Performer volumizer node
did.
the Caveat below, along with its adendum in the next email you sent, is
alittle unclear to me, but it seems to imply that i should be able to do
things like dynamically modify polygon caching parameters, volume region-of-
interest size and locaton, etc., etc., from, i guess, the APP process.
please correct me if i'm wrong here.
> You may then manipulate the pfColortable in any process you wish.
>
> is there a straightforward way to get any number of
> > variable data parameters from the computational process to OGLVolumizer in
> > the Performer node?
>
>
> Do you actually mean COMPUTE? or APP? Either way, recall that pfVolume.C is
> provided as sample source code for implementing a volume in Performer. You'll
> need to alter the source code to get what you want. I assume you want to make
> calls like:
>
> voAppearanceActions::getBestParameters( ... )
>
> etc. These could be exposed in the pfVolume class API, somehow I suppose.
> Dave, any thoughts on implementing this?
>
hmmm. there needs to be a way for these to be exposed in the pfVolume class
API, somehow i know, for there to be useful functionality here.
> -don
>
>
> Caveats. Remember that the Volumizer data is initialized and manipulated in
> the APP process, which does not have a graphics context. The results of
>
>
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