Body Capture’s skeleton in Moves by Maxon
Posted: 17 June 2021 12:50 PM   [ Ignore ]  
Total Posts:  2
Joined  2016-07-15

Hi,
I did a Body Capture in Moves and I’m not able to connect its rig to a model. The model that has been rigged with Mixamo and works well when connected with the Character Solver to the default Motion Captures that are in the C4D’s Content Browser.
I see that the Moves skeleton has 7 joints in the spine while the Mixamo and Content Browser’s one only 3, do I have remove some joints or connect the model directly to the Moves rig?
Thank you

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Posted: 20 June 2021 12:53 PM   [ Ignore ]   [ # 1 ]  
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Hi marcorosella,

Spline retargeting might be a way (Character Object> Mixamo Rig)

Reducing Joint Amounts:
This is not a trivial problem, and I can only hope that many people write a suggestion to Maxon to allow for a Mixamo export option.
https://www.maxon.net/en/support-center
Open a support ticket> Suggestion

One problem can be explained with the overall length of an arc, as a spine can form an arc. Thinking of an arc with an equal radius, it matters how many segments are used. The summary length of all segments will vary based on the number. Think of a circle represented by a triangle or an n-gon with 64 segments. (The near circle-like spline will be around 20%+ longer).

This excludes just to average the center joints and apply the value to the center joints for the low joint solution.

This and several other problems are perhaps of no importance in one or the other case: An Artist call.

Another option, more a brute force, to reduce every second joint to zero length while compensating for the loss of size with the previous. Not ideal either, but a quick fix. For moderate changes, that might work (?).

Joints typically work with rotational values only. The position where that rotation happens is crucial for anything that follows after that.

I have attached a scene to showcase the problem, going from more (5) to fewer (3) segments. This is in no way thought of as a solution, more to initiate brainstorming for specific cases. The file introduces a stretch and squeeze, which might not be wanted at all.

https://www.amazon.com/clouddrive/share/2QsUn6QN7x7FYA21b0Dr3mFqUBN9ne36CTu5uryebVE

Cheers

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Dr. Sassi V. Sassmannshausen Ph.D.
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Posted: 22 June 2021 08:55 AM   [ Ignore ]   [ # 2 ]  
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P.S.: Even the Spline IK might introduce its own little challenges (like twisting easily). If nothing else helps, this might be an idea to convert a chain of joints with many elements into a similar length chain with fewer elements.

https://www.amazon.com/clouddrive/share/5F4PwjF1Jpahan9nfyGHTpUcU84uQ4iSzdk5Z2onnvR

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Dr. Sassi V. Sassmannshausen Ph.D.
Cinema 4D Mentor since 2004

Photography For C4D Artists: 200 Free Tutorials. Texture, Panorama, HDRI, Camera Projection, etc.
https://www.youtube.com/user/DrSassiLA/playlists

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Posted: 28 June 2021 09:53 AM   [ Ignore ]   [ # 3 ]  
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Joined  2016-07-15

Thank you so much, I’ll continue to explore in both directions.
M

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Posted: 28 June 2021 10:02 AM   [ Ignore ]   [ # 4 ]  
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You’re very welcome, M.,

Thanks for your patience in that.

This problem has been on my mind for a while. One could build a Converter (two rigs) while using the Joints with Positions (Xpresso), introducing a new set of problems, but perhaps there is a sweet spot somewhere.

It will be easier if it is evaluated on a case-by-case file, based on the given motion.

My hope is that this could be solved in the MovesByMaxon app, providing a native Mixamo setup, to begin with. Which would undoubtedly require writing a suggestion to Maxon to document that there is interest.

https://www.maxon.net/en/support-center

All the best

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Dr. Sassi V. Sassmannshausen Ph.D.
Cinema 4D Mentor since 2004

Photography For C4D Artists: 200 Free Tutorials. Texture, Panorama, HDRI, Camera Projection, etc.
https://www.youtube.com/user/DrSassiLA/playlists

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