Deforming IK-Spline while moving Rig

#1

Hello there :slight_smile:

I have some problems with two IK-Splines in my rig. I had this problem for a while (also with other rigs) and still don’t know how to solve it.

I created two IK-Splines for the back and the tail of my doglike creature. I used the CVs to create clusters. So I have an important question there. I’m not sure what the checkbox “relative” does at the cluster attributes.

Then I grouped the cluster to itself (did center pivot) and parent constrained it to a controllobject (CO).

Now I can move the CO around and the spline starts deforming as it should.
I parented all CO to a main-CO and when I move my whole rig, it starts deforming.

That’s how it looks normally (Cluster+hierarchy+settings of the cluster)


That’s how it looks like, when I move the Main-CO

I hope you can help me to understand this problem and fix my other rig.

Greetings

Sorarey

#2 
Hi,
I found relative of cluster a little confusing too.

I'm thinking whats happening is because Relative may be Off, moving your main control which has a cluster further down its hierarchy is moving the cluster's immediate parent hence moving the thing the cluster is deforming and the cluster.

I think with relative for cluster deformer:
Relative Off, moving parent (null right above cluster not the cluster itself) moves what its child (cluster) is deforming (example cv)
Relative On, moving parent doesn't move what its child (cluster) is deforming.
(note for both cases of relative moving the cluster itself moves what the cluster is deforming.)
(figure [http://www.flickr.com/photos/76278515@N02/7042875129/](http://www.flickr.com/photos/76278515@N02/7042875129/))

Two ideas that may or may not work.
I think you could make the cluster relative off and have cluster's immediate parent (the null right above the cluster) have inherit transform off.

You may want your clusters to have relative on so your main control doesn't move them.  

Hope this is helpful
Regards,
Nate
#3

Thank you for the answer. I understood a lot more about the relative now.

I tried out both, with relative on and relative off and nothing worked for me. I don’t know how to parent my cluster and controller for those so the spline will move correctly with whole rig.

I tried out with groups+parent it under the root_jnt. Parent the Controllobjects under another controller. Parenting the IK-Handles of the IK-Spline.

So the only thing that worked for now… I have to take all Cluster-CO out of the hierarchy…With that I can move the whole rig without any deformations and the clusters still work.

The same problem appears at the tail. I have 3 clusters + Cluster-CO there and one controller which should rotate the whole tail.

When I rotate whole tail the CO move correctly but the Splines starts “curling”.

And I need one advice.

I did 2 spline-IKs. One for the back and one for the tail…would it be better, if I would use a single spline-IK for both?

Greetings

Sorarey

#4

Hi,
I don’t know if this would help but have you turned inherit transform off on all the spine ik curves (this is so curve cvs wont move when the curve’s parent is moved)?

Regards,
Nate

#5

Hello Nate! :slight_smile:

I just checked the two Spline-IKs but they have “Inhertis Transformation” on.

So it seems that I can’t move or rotate all CO, which are controlling the Cluster of the Splines/Spline-IKs.

As I said…if they aren’t in an hierarchy, I can move the whole rig around and the CO still work…but they are at their 0-position while the rig is somewhere else. (So it would make the animation very difficult to handle, especially when I have to rotate the whole rig)

I just googled a bit and found out that the spline gets double transformations. Someone said to that those splines shouldn’t be in the bone-hierarchy. But I parented them under the main-CO. Another person had the problem, that he created some clusters and didn’t use them. So I don’t have unused clusters but what I have are unused CVs.
Might that cause the problem?

So I asked my teamleader and she allowed me to upload the rig, so you have a better idea why this thing is not working. :slight_smile:

My Dog-Rig without a Mesh

Greetings Sorarey!

#6

to Sorarey
I just download and check your work. Since i’m at company, i can’t fix it right now but i see there a few problem.

  1. For the Spine part. Chose the First Cluster (The one which nearest Hip) uncheck the Inhertis transform.
  2. For the tail part, look like you miss one cluster which control the tail.

=====================
wow, you made so much mistake than i expect,anyway here is the problem.
I just tell you about the tail part and then you do the rest, okay?

  1. tail_wag_jnt and tail_root_jnt, you put 2 joint in diffirent position so when rotate the control curve which driver the tail_wag_jnt, the tail_root_jnt will be offset for a bit. Also, the center of the control curve is not in the joint’s pivot. And why you orient constraint and parent constrain the same time with tail_root_jnt?
  2. about the cluster and curve. You miss 1 cluster which driver the first CV, and there are alot of Cv has weight 1 for both 2 cluster. Also alot of CV hasn’t been driver by any cluster either.

After fix a few thing, i think it’s ok, when i move the main controller curve. The tail is fine, same for the FK.

so…

http://www.mediafire.com/?lz0fzoeadec9284

I had fix the tail part. Take this as refrence. Hope this help :slight_smile: Cheer

#7

Thank you very much!!! That helped me a lot and I’m going to practise what you did on a copy of this rig (which doesn’t work right now)

So to make it clear.

There has to be one Cluster for each CV and every CV must be controlled by something? And there are no double weights allowed?

I learn by checking other rigs and how they are made. But the only rig I learned from is the half finished rig by my teacher. But that was a human rig…which I thought wouldn’t matter because the technique are the same.

I want to understand rigging a lot more and going to check what you did with it and where you put the pivots! :slight_smile:

Greetings

Sorarey

#8

Base on what you just told, there’s a long way to go. However
Cv can be control by many Cluster (in this case), it’s just about the weight, don’t ever set the overall weight higher than 1. For exam, you have 2 cluster driver 1 CV, so the weight should be 0.5 0.5, not 1 1.

If you’re new to rig. How about check some tutorial about rigging in Maya first.
Cheer
Tuan

#9

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