Robert, Thanks for the quick reply.
If I understand the NodeMask and CullMask, these would cull entire nodes, not individual osg::Drawable instances, correct? For example, I have geode's that contain a text label as one of their drawables. I thought about using a switch node to toggle the text on and off, but that seemed a bit heavy compared to a callback. With my draw callback, I can easily turn labels on or off for the entire graph. The penalty is that those drawables cannot use display lists. Cory On 7/6/2010 3:16 PM, Robert Osfield wrote: > Hi Cory, > > This is expected behaviour as the draw callback is nested within the > code that sets up display lists, so once the display list is created > it'll not call the callback again. If you disable the use of display > lists via drawable->setUseDisplayLists(false); then your callback will > be called on every frame. > > Another approach you could take to switching on/off various subgraphs > is to use a combination of NodeMask and CullMask. Have a look at the > osgstereoimage example for inspiration on this approach. > > Robert. > > On Tue, Jul 6, 2010 at 8:19 PM, Cory Riddell <[email protected]> wrote: > >> I have a very simple draw callback defined that uses a bool to decide if >> the drawable should be drawn. The body of the callback's >> drawImplementation() looks like: >> >> if (m_enable) >> { >> drawable->drawImplementation(renderInfo); >> } >> >> I have drawables scattered all over my scene that use the same instance >> of this callback. By doing this, I'm able to toggle all of those >> drawables on or off by setting a single bool. >> >> This only seems to work though if the drawable has display lists >> disabled. My code to set the callback looks like: >> >> drawable->setUseDisplayList(false); >> // callback is my shared callback instance >> drawable->setDrawCallback(callback); >> >> Is this expected behaviour? If I understand this correctly, to use >> display lists, I would have to tell each drawable to recompile >> (dirtyDisplayList()) whenever I toggle my m_enable bool. Since the whole >> point of my shared draw callback is to avoid traversing my graph, doing >> so would defeat the purpose of my callback. So, do I understand this >> correctly? >> >> It looks like display lists can prevent a draw callback from being >> called. Is that right? >> >> Cory >> >> >> >> _______________________________________________ >> 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 > > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
