How to make an IK/FK Slider

Hello everyone !
First, sorry for my poor english, I live in France, so…

I try to make an Ik/Fk switch with a slider to control arms of my character.
It works but, moves of the slider doesn’t change the influence of the constraint in real time, I need to change the current frame to see the modifications.

I saw blend files of the BBB team, their sliders work in real time, I don’t understand why ?

Could you help me ? Thanks.

If you are using an IPO driver then look at the IPO window. There is a little icon like a lock. Click on it. If forces other windows to update in real time.


Thank you doncuan for your reply.
Yes I’m using an IPO Driver, I clicked on the lock, but nothing changes…

considering your IK/FK constraints and sliders are all properly set up, you may have to hit the up button to jump ahead frames then hit the down button to “refresh” the IK/FK switch, Blender as of this moment has a problem with it.

I found the solution !
This button don’t have to be clicked !
Thank you every one