Cineversity

Hi there,
have been working on a rigging setup to unfurl a joint chain like this video https://www.youtube.com/watch?v=xN8c_X0LNcg

so far i’ve used xpresso with an hierarchy iterator and a falloff node to drive joint rotations (have attached my c4d file).  But i’m wondering if it could be done so that rather than using a falloff node, you could have a custom user data percentage that controls the unroll down the length of the chain? 

Does that make sense?  So at a value of 0% the whole chain would be curled up, at 50% the first half of the chain would have unrolled and the second half still be curled up, and then at 100% all the joints would be straight

Or are there even better ways to do this?  I need to use joints as i eventually want to bind geo to it

Thanks : )

Hi Rich,

The first idea that I have integrated, was to select all and type in S.Z a number smaller than “one”. With 0.95, I was able to create a chain that progressively becomes smaller to the end of the change, as the result you like to have was a spiral. This value is chosen randomly, change it if needed. To do that, I have a selection object in the Object manager.

The idea was to have a Range Mapper do the work for me. So, the progress of the “chain” is based on the change of the Input-lower-upper; (clamped).

Check out the file and let me know if that is working for you. I tried many options, but this seems to be the simplest set up, with the most options (change the Spline curve of the range Mapper for a different “feel” in the individual progress for example.

The output upper will determine the max angle. Note that this is 2*PI for a 360º.

All the best

P.S.: MoSpline has some options for this, but needs some experimentation to get there.

P.S.: For much smoother movement, the number might be chosen larger. The more Joints need to be in movement, the larger the distance between Input Lower and upper should be. The subtraction value leads here and the start value should be equal or slightly larger.

The Output Upper changes the max angle.

Have a look the file. Clearly, much more joints would be nicer, or a better mesh, perhaps both.

P.S.S.: (I couldn’t resist to go even further. ;o)

I believe the only term that I use in the User Data that needs an explanation is “span”. This is a value that tightens or expand the area which Joint is involved for the current change. Current change means joints which are not completely rotated or just straight.

The max. Angle tightens the spiral of course.

The Bend Deformer is introduced as plants have a natural bend. Adjust it.

I used spline to joints and after the joints where scaled 0.97, I used the joints to spline command to create a nice fit for the object.

The file:
https://www.amazon.com/clouddrive/share/U4rYZ1y-0u_uXxQdzwHytBYGrKNhanMb8sk82Cz2g0g?ref_=cd_share_link_copy_flash

Enjoy.

Oh wow, thanks Dr Sassi.  Sorry i didn’t get an email about any replys to this thread so have only just seen this.  Thanks so much for taking a look - gonna have a look through all your setups in the next day or so!  Much appreciated : )

Hi Rich,

Thank you very much for your feedback. It was a fun question, and as you can see, it was more than a pleasure to explore this.

Just to give a hint: The Range Mapper moves over them—as a Falloff, to describe “visually” what it does mathematically. I really love this set up (the last one)

If you have any questions—please just “shoot”!

... and yes, the e-mails are not coming in here as well—from time to time. No idea where the problem is. Sorry about this.

Have a nice evening

Yes, just been having a look through it.  Really fantastic setup, thanks again.  I knew it could be done but could quite figure out the correct way with the range mapper.  This is a great learning example.  Goes to show the advanced setups that can be created with xpresso.  Thanks very much for your help!  Have a good evening too

You are very welcome, Rich!

All these questions keeps me on my toes, and I love it.

Enjoy!