This specialization on
CallbackDatais passed when the callback is initiated from deep within the draw traversal, for a particular Geom.
Returns true if any required data should be forced into memory if necessary to render the object, or false if the object should be omitted if some of the data is not available (at least until the data becomes available later).
Returns a pointer to the particular object that is being drawn.
Sets the lost_state flag. If this is true, the callback does not have to be quite so careful to clean up after itself; Panda will assume that the graphics state is in an unknown state after the callback has finished, and will issue all the necessary calls to restore it. If this is false, Panda will assume the callback will leave the graphics state exactly as it came in, and won’t bother to try to restore it. The default is true.