connecting two circular paths

I have two concentric circular paths (generated from bezier circles), and I want to have a camera track to the outer path for one orbit, then smoothly spiral in to track to the inner path for one orbit. There does not seem to be a way to add a start frame either to a Track To constraint for the camera, or for the paths. Any suggestions?

Thanks,

Will

You can key any constraint . Just apply a follow path constraint to the camera for each circle/curve/path (make sure you have curve path enabled) then open up an IPO curve window . Then in the buttons window in the constraint panel you can either hit I and insert a force strength or force fall off key or hit the “key” tab at the bottom of the constraint panel . Once you have inserted the initial key just go to the IPO window and and Ctrl-LMB to insert a key where you want the first circle’s constraint to fall off to zero, then go to the second circle and insert a key to where you want its influence to start . The IPO curves for each circle should mirror each other so that when one is at full influence (max 1.0) the other is at zero etc . You might have to play with the curves a bit to get the transition smooth .

What I would do is have an empty following each path, and two copy location constraints on the camera targetting the empties. Ensure the empties have the same RPM, and then it’s easier to smooth the transitions between one and the other. If you want to speed up or slow down the rotations, then adjust the time IPO curve on the camera. (But this will also speed up/slow down transitions)

Hey VertexPusher - that’s really neat. I didn’t know you could do that…wiki updated…http://wiki.blender.org/index.php/Manual/Constraints/Constraint_Stack