Speed up Spline IK process

[Pitchi]

Hello, I'd like to quickly create IK splines. I'm using this video as a guide, and I'd like to know if there's a quick way to go from this hierarchy of joints to this one with nulls? (See the C4D file and the video link). Perhaps using a script? Or is there a simpler way to create an IK spline? I also want to use Bendy Bones as inspiration in Blender.

link :https://youtu.be/6Ctda4TSYYc
Joint_hierarchy.c4d

Thanks

[Dr. Sassi]

Hi Pitchi,

Thanks for the file and the link.

I think my dear colleague Rodrigues has done a great job.

Finding a faster way is always a good question.
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A script would be the question for the Developer Café
https://developers.maxon.net/forum/
Scripts here are not allowed for security reasons. As they can be updated, and it would be beyond my time to check those every hour, to avoid harm.
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I have experimented a little bit, while keeping the shown results of the video in mind as a target. Like Align to Spline or another option.
Of course, I have to mention that Cinema 4D has the Toon character set up. Which is surely the fastest way to get a very complex, yet easy to animate rig in the "pipeline".

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Below is, in my opinion, the fastest way, especially if you have huge numbers of those.
The one joint (bone can be set into many with the shift click "split" function. Convert them into null can be done, but is perhaps not needed. In the example I have done it, to follow the question.)
The transfer is then done with a simple iteration XPresso setup.
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To get many Single Joints, CMD drag one, select the two, CMD drag these, select the four, etc. In no time, you have a lot.
Joints and Nulls each go into the Link List, and both get connected to an Itteration. If you have nine joint objects, then the iteration is 0-8.
Drag one joint and one Null into the XPress editor; they serve as "Receiving Container", and get via iteration>Link Linst all Objects sequentially as output.
Transfer the Global Position and Global Rotation to it, if you like to adjust the Scale of the Joint. Other wise the Global Matrix does the trick with one connection between the Nodes.
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I have frozen the Coordinates of each object, so if a reset is needed, use the Reset PSR function.
CV4_2026_drs_25_CAxp_01.c4d

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If you have any questions, please let me know. I'm happy to look into it.
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Enjoy

[Pitchi]

thanks you ! yes I think using a script is the fastest way if I need to create about twenty IK splines; if I remember correctly, they often use scripts for rigging in Maya.

[Dr. Sassi]

Hi Pitchi,

Thanks for the reply.

The file I have shared, I can redo in five minutes. Which means with a coffee break, that would be an hour
Since I do not know your project, it is hard to tell more.
Often, I encounter that going back to the initial idea of the character and its needs might trigger some other ideas.

The key would be Python; however, it might take longer to script this than to do it manually.
Here is an example with an PLA animated spline.

CV4_2026_drs_25_CAsw_01.c4d

Here I use the Spline Wrap
The object stays in place “virtually”, and can so easily be changed with "local" Deformers, like the Bulge.
The Splinewrap (I have its bounding box fixed here) can easily change the shape with its integrated Spline Interface Adjustment: Size and Rotation.

If the single Spline set up creates some trouble, a Raid Spline can be used, but of course, that increases the complexity.

I'm sure there are more ways, but each character setup might need something else.

Let me know if you'd like to dig deeper. I'm happy to look into it.

Happy Holidays!

[Dr. Sassi]

P.S.: One more, perhaps that allows only for more input on your side, but maybe works as is.

The concept is simple: Two Nulls are the main handles, start and end. They each have two child objects attached. These four allow the Tracer to create a spline.
To gain data about the rotation of the two handles, two more Nulls are used as Child Objects for each Handle. This is then used in a second Tracer to produce a spline again, but this time it is a Raid Spline.

I have animated one side. The Scale is in the Spline Interface of the Sweep object.

CV4_2026_drs_25_CAmg_01.c4d

Enjoy