Getting a good Tail setup with mGear

[Kane_Forster]

Hey Guys,

So I need to create a ‘Bipedal’ rats tail that can move pretty fluid but on top of that it also needs to be able to have an ability to curl at the end to pick things up ( completely realistic )

I figured I could have a duplicate system for the curl and use a blend shape to add it to the original mesh.

I found the mGear Tail tutorial n Youtube using a spring chain and extra spline controls
I used it but for some reason, I keep getting twisting on the tail

Is there a way for me to prevent the twisting with this same setup, maybe an option i missed?

Or does anyone have a suggestion on another shifter component that would do a better job ?

[chrislesage]

I’m not sure about a Shifter component. I do use chain_FK_spline_01, but our tails don’t need to spin and twist very much. When I test it, it does flip in extreme poses.

But I would personally probably use a ribbon IK in this case, because then the twist is more directly controlled by each controller. (Another thing I might do is use the spring chain, and then put a ribbon IK on top of all that, if you still want the benefit of the spring.)

And, if you need to find a way to make an ultra-robust tail that can be flexible AND curl and grab things, but are faced with a realistic deadline, you might want to consider making 2 separate rigs instead of trying to engineer one perfect one. One where the tail is already in a grabbing pose. (That kind of sounds like what you described anyway, with a blendshape.)

[Kane_Forster]

Hi Chris,

Thanks so much for these great tips!

I don’t know why I didn’t think of a ribbon setup, combining that with the spring to still have the dynamics set up is a great idea! I need the rig ready by Monday but I am currently a student in my final year so weekends count as workdays, meaning I have the time but also don’t really

I’ll share the route I end up taking but will definitely try this out !!

Many thanks again

[Arthur.C]

Hi Kane,
Try duplicate all rope00*_jnts , parent duplicated joints to hierarchy and constraint them
to corresponding rope00*_jnts. I fix twisting issue using this method. sorry for my bad English.
Hope it helps!

Cheers,

Arthur

[Chantelle_Badenhorst]

Hey Kane. When setting up the tail, did you skin your tweak joints to both curves (the curve and up vector curve)? Because it looks like there is a curve staying behind, and I think if you did not skin the up vector curve then I think it might be twisting because when you move above the up vector curve the joints flip as they are using that curve to determine which way is up. I might be wrong, so let me know if it works.

[Kane_Forster]

I think you might be right Chantelle I’ve ended up just using a chain_stack for the tail now… But if I need to use dynamics later during production I will definitely make sure I skin both curves

Good eye

Thank You

[Kane_Forster]

Hey Arthur thanks for the response, That seems like a good work around… I’ve ended up just using a chain.stack due to time constraints but will look into this

[Kane_Forster]

So I ended up finalizing the tail I needed. My first issue was that I didn’t bind to both curves… so the twisting is not a problem anymore unless pushed very far

I ended up combining 2 spring chains and then binding them to 2 curves, creating a rope from the curves and viola. A tail with dynamics and curves while also being able to curl at the end

( I still need to weight paint )
So i used a 5 section spring chain to control the main part of the tail and the parented another 10 section spring chain below it.

Then created a curve with vertexes for each joint. Binding the necessary joints to the curve ( skipping a few duplicates )

Then finally using the rope to blend the two chains into one smooth joint chain.(the only issue is that I don’t know how to script the rope ) but everything else is scripted so I don’t mind manually setting up the rope if needed

Its not the most dynamic system but it works fine for what we need and manages to hold up pretty well with big rotations.

I also created a pinning system for the tail so the character can walk only affecting the z-axis of the COG so it stays locked on the ground. Was less complicated than expected, using constraints and expressions to get it working with on switch

Thanks for all the help everyone!