Hi Lee, Clip planes are position state, so have to be positioned in space by the osg::ClipNode, but the actually enabling of clip planes is decoupled from this and control through osg::StateSet::setMode(GL_CLIP_PLANE0+i, osg::StateAttribute::ON). You typically wouldn't decorate your scene with the ClipNode, rather you would usually place the ClipNode in your scene and positioned appropriately, then enable the individual clip planes for the subgraphs you want them to be on by just setting the modes (as above) via a StateSet that is attached to root of subgraph that you want to enable it for.
Robert. On Mon, May 11, 2009 at 8:02 PM, Butler, Lee Mr CIV USA USAMC <[email protected]> wrote: > I want to turn a cutting plane on and off at various levels in the graph and > update it under user control. The osgclip example was enough to show me how > to add the clipping plane. Getting it turned on and off is something that > somehow eludes me. I'm having trouble understanding the "OSG way" of doing > this. > > Code looks like this: > > // load geometry, etc ... > // add clip node > decorate_with_clip_node(scene); > > // set attributes on stateset ... > > MyVisitor myVisitor(stateset); > > while (!viewer.done()) { > viewer.advance(); > viewer.eventTraversal(); > viewer.updateTraversal(); > viewer.renderingTraversals(); > } > > When the user presses a key to toggle the clipping plane I do: > > clipped_subgraph->accept(myVisitor); > > which in turn does: > > if (node.getStateSet()) { > node.setStateSet(NULL); > } else { > node.setStateSet( _stateset ); > } > > > The first time the NodeVisitor runs it claims to turn off the StateSet on the > graphNode. Yet the clipping still occurs. On the second pass through, the > stateset pointer is no longer valid, as if it had been freed. I've checked > the reference count on the stateset after the call to node.setStateSet(NULL) > and the it is still 2, so I wouldn't have anticipated it getting destroyed. > > Clearly I'm lost in newbie-land. I've tried searching the archives, but I > haven't found the right posting and the website doesn't seem to be very stable > this month. > > Help? > > Lee > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
