Newbie questions

I’m trying to create an animation, where several objects travel along the same curve, separated in time. (Imagine a cannon, repeatedly firing at the same target. All the “cannonballs” will take the same path, but since it can only fire one at a time, they’ll be staggered.)

But, I can’t figure out two basic things:

  1. How do I have an object that isn’t around for the entire length of the animation? For instance, it comes into being at frame 20, and goes away at frame 32.

  2. How do I make multiple objects follow the same path, only at different times? I’d rather not duplicate the curve for every single follower, but I suppose I could.

This is (eventually) going to be part of a prodceural animation system, so if the answer includes Python code, that’s fine. Ultimately, a script will be controlling the lifecycles of these objects, anyway.


In F7, Anim Settings tab at bottom-left you can set the TimeOffset of each object parented to a Path in Frames.

Object IPO’s have an option in the right-hand column ‘Layer’ with which you can keyframe an object from a hidden layer to a visible layer.


Aha! I missed that one. I think I was trying to use a “Follow Path” constraint on the object, and using the “offset” parameter of that. But, either I didn’t understand how to use it, or it was the wrong tool for the job.

And that should do the trick. I think I need to learn more about layers, in general…

Thanks for your help!

I think I was trying to use a “Follow Path” constraint

Ctrl-P parent the Object to the Curve and choose Follow Path.


Yup. That’s exactly the trick.

I’ve also started playing with the Time channel in the IPO, which looks like it might even let me re-use the same object, at different times. Eventually, I plan to have lots and lots of objects flying around the scene, over the course of an animation, so being able to reduce my memory footprint will probably be a good thing.

Thanks for your help!