Hi Robert,

Robert Osfield wrote:
As for having multiple home positions, perhaps having mulitple camera
views that you can move between would be more appropriate.  One could
possibly decouple these camera views from the specific camera
manipulators, and provide a scheme where a CameraView placed in the
scene graph could act as the place that a camera manipulator moves to.
  

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?

W.r.t animation between camera views or even manipulators, this would
be nice, again I do wonder about a general solution rather than a
specific one.  Camera path interpolation is quite easy to do until you
need to start doing path planning to avoid moving through objects
along the path such as terrain.
  
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.

If we can come up with systems for the above that are decoupled from
specific manipulator implementations then we'd be able to use them in
a more flexible way, and avoid having to re-invent the wheel each time
for each manipulator.
  

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.

Cory






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