Tuesday, 25 February 2014

@ Alan

Hi Alan, I have been trying to create a moving chain which would rotate around some gears. I was trying to work out a way that I can do this which lead me to a tutorial  around using a nurb curve, which of course, I have come up with some problems. Here is the tuorial I have followed.

 It basically links a link to a nurb curve by using motion path which attaches it to the curve. It then duplicates around the curve by using, create animation snapshot. This part works fine.

I then placed joints around the curve by using a locator which is also attached to the curve using motion path. It then gets a little iffy from here.
 It then shows in the tutorial to select the IK Spine Handle and fiddles with the settings (shown in the second image). He resets and then deselects auto parent, snap curve and auto create curve. He then selects all the joints and connects the IK to the joints. It is here that my problem begins. When I tried this it does not allow me to selects the joints coming up with an error (bottom image). It pretty much just says that they are not seen as joints?  I tried using the IK spine just on a few joints in a separate file but still I could not get the Ik to work at all (even with all its settings reset it would come up with the same error). I have made this both on the uni computers and my own laptop but with ended up with the same out come.

Is there a solution to this or an easier way to animate a move chain around a couple of gears? 


  1. Hi Mike

    In essence this is the right way to go about creating a chain - Create a curve (even CV's), create a joint chain along the curve, and then turn it in to a spline IK setup and animate the offset channel. Once you have that you can parent any geometry to the joint.

    The error your getting seems to be caused by your selection. In the outliner the selection isn't a joint chain, its single joints? There are no names too which seems like a bug? - To create a spline IK setup, go to the options and turn off 'auto create curve' and 'auto parent curve' and the click on the 'root' of the chain (first joint) and the one the end joint and then on the curve. You can only do this in the viewport - If you have the start / end joint on top of each other it can be hard to select so before hand select one of the joints and change it's 'Radius' in channel box.

    1. Hi Alan

      It seems that it was my mistake with selecting all of the joints instead of the beginning and end. Thank you for your help and I'm glad that in essence this is the right way and that I'm not just trailing off.

      Thanks a bunch and get well soon