Can I clarify than if a cull callback gets called for a node, that means the node will
be visible ? Would than the boolean node.getCullingActive; tell you if a cull callback has been called ? If so do I have to initialize a cull callback for a node I'm trying to watch (cause I would think culling is done automatically) Thanks! -Bryan -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Robert Osfield Sent: Wednesday, April 16, 2008 10:13 AM To: OpenSceneGraph Users Subject: Re: [osg-users] placing image on scene On Wed, Apr 16, 2008 at 5:42 PM, Bryan Berg <[EMAIL PROTECTED]> wrote: > So my question is: how can I take a specific point of the scene and than > > a)determine if it is to be viewed A cull callback only gets called if the node hasn't yet been culled so its one way of determining visibility. Its not 100% accurate as bounding volumes are larger than the model they enclose so its overly conservative. The only 100% reliable way is to render the objects and use the OpenGL occlusion query extension to find out how many pixels are visible. > b)if so, which window coordinate it corresponds to >From within a cull callback you get get the accumulated modelview, projection and window matrices that you can use to project the local object coords into window coords. Robert. _______________________________________________ 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
