Anybody any good with IK solvers???

[Dave Buckley]

How come i can't add an Ik solver to a group????

 

I have group some gemoetry together to form a pivot (example: nuts, screws and cylinders make up the pivot via grouping)

 

I then need to apply an Ik solver to this group (i have already created a hierarchy) but it won't let me???

 

Any ideas, included is a schematic screenshot of the hierarchy i have created, the green ones are the groups, the blue are the parts making up that group.

 

The green bits are 3 pivot points and 2 'arms', think of it like a robotic joint.

 

Have i done it wrong or can i not apply Ik solvers to groups

[RobNJ73]

Just to try to wrap my head around your question... you've got the objects linked together (making an FK chain) and grouped, and now you need to apply an IK solver to the group as a whole?

 

Is the IK solver you're trying to add only on the one group? Or is it connecting multiple groups together?

 

I'm not positive about attaching IK solvers between groups, but I don't think you can... if memory serves, IK solvers need to be attached between two or more individual objects.

 

I could be wrong though... it's been a while since I built a rig from scratch.

[Paul Twyman]

Hi there,

I haven't built a rig for awhile either and it's a bit hard to get your head around one when it's not your own but from what I can remember groups don't work. I think it's because even if you change the pivot point of the group it still has individual objects with different ones and the solver wants to look at all the objects.

You can still keep your objects grouped but use a dummy helper object for each group. Center a dummy to each group and adjust its pivot to where you want it. Then link each group to its corresponding dummy so that it will follow it.

Then when adding the IK solver use the dummys not the groups, this way there should be a single pivot point for each point that the solver is trying to work out.

 

Hope this helps, I think it should work I used to use IK solvers a lot but was quite awhile ago

[Paul Twyman]

Just adding to my previous post, missed a bit out!

Obviously you'll have to break the link between all your groups and then re apply the hierarchy using the dummies instead of the groups. Basically use the dummies for anything regarding the linking.