Speed up Spline IK process

[Dr. Sassi]

P.S.: I was too curious, so I used my private account to download it (since it is a new Mac, and has its own router, for now I can take a risk…), your rig is impressive.
Thanks for sharing, and I will think about it.

[Dr. Sassi]

Hi Pitchi,

Here is a "One Minute" workflow. I used 12 joints for this, but it works with any number, dependent on how you need it.

https://projectfiles.maxon.net/Cineversity_Forum_Support/2025_CLIPS_DRS/20251225_SplineJoints.mp4

At the moment, I can't think of anything faster. Well, if you have a similar number of joints, then the joint production can be just to copy the group with the Align to Spline already attached. Then, with some routine, it is half the time.

Of course, the handles need some attention, the Joint used for this should be not weighted/bind.
CV4_2026_DRS_25_CAsj_01_.c4d

Cheers

[Pitchi]

Nice thanks you yes i tried the face rig tutorial introduction but i can't do exactly what i want. I tried something else; in the IK spline tag, I can link the size of a null to the length of the tangent of a point on the spline. I think I'll create a setup with the spline, joints, and nulls, which I'll then duplicate and place on the character.

video link : https://wetransfer.com/downloads/1f5879cfef13990556c146a3b11a22ea20251226105108/1583f6?t_exp=1767005468&t_lsid=fedd0751-1e46-4996-bda5-0e13466adbf7&t_network=link&t_rid=ZW1haWx8YWRyb2l0fGIzNzkzZDA2LTJjNzAtNGM5NS1hYzk4LWM5NDFjNjZjYWM2Yw==&t_s=download_link&t_ts=1766746281

[Pitchi]

I think I've found a fairly simple and quick setup to implement on a character.
video link : https://we.tl/t-NHA42iH0PP

SETUP_IK_SPLINE.c4d

[Dr. Sassi]

Thank you very much, Pitchi, for the files and clips!

I took your file and placed some ideas into it, since your request was to speed up things.

The key was to keep the Joint objects out of the Hierarchy; otherwise, any scale on one would affect the object below.
I find no problems using just one Joint object to run the Spline IK. (Not a big time saver…)
Instead of setting up the User Data, you could "wire" the Null object Shape size to the handles, which allows you to get more visual feedback.
CV4_2026_drs_25_CAsi.c4d
Let me know if there is anything else you would like to explore.

Cheers

[Pitchi]

good thanks you, yes it's good for me, i found a good way to place quickly the IK spline on face

thanks you !

[Dr. Sassi]

Thank you, Pitchi, for the reply.

In summary, this sounds like an interesting exploration, and I hope you have some time after the project is finished to share your impression, or if you can, the results (if it is public).

"P.S."
To complete this thread, I have explored the Spline Deformer with a Multi-Segment Spline. The option to reset it (Like with the Freeze option) is not given, and we need a solution, perhaps via XPresso. Also, the fine weighting for the face might be relatively hard to achieve, if not impossible. Since this could be a suggestion at one point, I wanted to share it.
CV4_2026_drs_25_CAsd_01.c4d
How it could be animated
CV4_2026_drs_25_CAsd_02.c4d
However, Character Animation might always include several influences, so this is just a brainstorming for now.

My best wishes for your project

[Pitchi]

Nice we can have good result with the Spline deformer It's a shame we can't multiple Deformer Splines on an object and use fields on them.

[Dr. Sassi]

Hi Pitchi,

It is kind of possible, but it takes a short detour.

Example
CV4_2026_drs_25_CAsd_11.c4d

The key is to keep the point amount the same, e.g., not Adaptive (Across all elements, including MoSpline)
I think it is time to wrap this into a feature request.

Cheers

[Pitchi]

good thanks you ! While experimenting with different techniques, I noticed that there could be additional tools for rigging. The Create IK Chain tool exists, but not Create IK Spline. A tool that allows converting an edge selection into a spline, then into a joint, and then adding an IK spline with controllers all at once would be ideal. This would eliminate the need to perform each step manually.

[Dr. Sassi]

Sound great, Pitchi!

Please share that with Maxon, and if others read a long and find that great, please add you voice as well.

Select edge or a connected series of edges "Edge to Spline"
For the direction of the joints hierarchy "Reverse Spline Direction"
Call up the function and add the amount of Joints "Convert Spline to Joints",
A check box if the Joints needs to be single or in a hierarchy, direction of the hierarchy.
Handles for start and finish or per Created Spline Point (related to the edge selection).

To create this suggestion use the
"Share Your Ideas"
https://www.maxon.net/en/support-center

Thank you! I will share that as well.

Enjoy your weekend