Jump to content
Hash, Inc. Forums

Kinematic Constraint not always 'holding on'


Octropos

Recommended Posts

Howdy all!

 

I am having some unexpected behaviour with a kinematic constraint to a null.

 

The setup:

 

I have a chain of 8 bones (it's in a tentacle, but that probably doesn't matter much) running vertically (parent is at the top, bone #8 is at the bottom).

 

I have a null that is doing the actual moving around.

 

I apply a Kinematic Constraint from bone # 8 (end of the chain) to the null.

 

Bone #8 now 'moves' over to the null, dragging it's parent bones along (just like if I'd grabbed bone 8 and moved it manually). This is expected.

 

Things go fine until the null raises (translates in the +Y direction) up past about 1/2 the length of the chain. After a certain height bone #8 still points at the null but is no longer 'attached' (doesn't raise up anymore), even though there is sufficient 'room' in the chain to reach the null's present location (confirmed by manually dragging bone 8 up to null).

 

It's like the top few parent bones in the chain don't want to bend or something.

 

All constraint and bone properties are defaults.

 

Version 12

 

 

Can anyone shed some light?

 

Thanks!

 

Eric

Link to comment
Share on other sites

  • Hash Fellow

Yes. I checked the whole chain.

 

I just tried an 8 bone chain and it worked fine unless "attached to parent" was off on one of them or if one wasn't really a child of a bone.

 

Kinematic chains only work on chains with no branches. If there's a branch anywhere in you're tentacle that would stop the chain at that point.

Link to comment
Share on other sites

Join the conversation

You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...