Hi Cory, On Wed, May 20, 2009 at 2:10 PM, Cory Riddell <[email protected]> wrote: > I'm not really grokking CameraView yet. I see that it is a transform node > with postion, attitude, focal length and field of view settings but it isn't > obvious to me how you would locate a camera with it. The docs say: > > The application must attach a camera to a CameraView via the NodePath from > the top of the scene graph to the CameraView node itself, and accumulate the > view matrix from this NodePath. > > So, I would accumulate the matrices from (one of) the node paths to the > CameraView node and then what? Pass this matrix into the camera manipulator?
Yes this is exactly what would be done, but it could possible be done as a one off apply against a CameraManipulator. For instance CameraManipulator could have a convenience method that takes CameraView pointer (and it's parent path) and works out the settings that are appropriate. > It seems to me that a spherical manipulator would usually be used by > CAD-type applications where you are always outside of the model. I don't > think I would build in any path planning to the animation route. You'd need to add the capability to control the path if required, so a default implementation could do something that works for 90% of users, then allow the last 10% to add the custom path planning facility. > I'm actually happy with having my camera position reset code in an event > handler rather than the scene graph because a relocate event is relatively > rare. Correct me if I'm wrong, but every additional node added to the scene > graph incurs some non-zero overhead on every iteration of the main loop, no? > Is the incremental cost so small it isn't worth worrying about? I honestly > don't know as I haven't profiled anything. Extra nodes like a CameraView has essentially zero cost, the traversals only traverse what is required, so passive nodes like a CameraView are largely ignored. Robert. _______________________________________________ osg-submissions mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
