ipos for constraints

I decided today that I would take a swing at animating an arrow hitting a target. Initially it was really easy; I just added a curve and got it into the arc I wanted the arrow to make, parented my arrow pieces to an empty, and then added a follow path constraint to the empty. The motion itself is fine, but what I really want to do is be able to control the animations speed over time. The only problem is that I am unable to get any sort of ipos for the constraint. I believe this may be because I haven’t inserted any key frames yet, and in that case I am still stuck because I don’t know how to keyframe motion along a path. Hope one of you has a solution.

Cheers.

You can use the Path IPO type and add a Speed curve (select the curve path, change the IPO type to Path, select Speed and Ctrl-LMB to add keys) .
I don’t think you’d want to use the Constraint IPO/influence IPO on the cube since this can give you wonky results with a curve path …