Floppy Ears on character?

#1

Greetings,
I have a cartoony animal character with dynamic floppy ears using an nHair system driving a Spline IK going through the bone chain of the ears.
Two problems though. The big problem is that the ears flop right through the character’s head. How can I get dynamic ears that won’t go right through the head? (the ears and body are one piece of geometry)

I tried turning the body geometry into a ‘nCloth Passive Collider’, but the ears still go through the head…

Another problem is that the ears stay very floppy no matter how I adjust the settings of the nHair dynamics. I increased ‘stiffness’ setting on the dynamic curves that drive the ears, and I’ve also raised ‘stiffness’ setting on the hair system itself, but the ears remain maximum floppy. Adjusting ‘drag’ and ‘damp’ are similarly ignored. Even at the maximum ‘stiffness’ setting of 1.0, ears still flop to max, ignoring the setting.

Thanks for the help!

#2

There are any number of things which could be causing your ears to not collide, the thickness of the nHair is the first thing to check. I would assume your ears are much wider than a default hair width. As to the flopping, the nucleus scene scale is something to check. It can affect the overall dynamics of your simulation dramatically. Also using the “start curve attract” will help you shape the ear and how it behaves. Without a scene or more specifics about what you have setup, it’s difficult to say exactly where you problem lies.

#3

“Stiffness” is an old solver attribute. I would recommend having “useNucleusSolver” enabled, in which case you need to set stretch/compression/bend resistance to high enough values. If the start curve shape is not straight then you may also need some twistResistance. Values need to be higher if you have more segments on the hair. As well you may need to increase substeps on the nucleus node to make it very stiff, especially if there are a lot of segments. A cheat is to use a little startCurveAttract, depending on the requirements.

(note if you don’t have useNucleusSolver enabled then you won’t see collisions with passive cloth objects)

Another possible control might be to use a low poly planar strip made into ncloth, instead of using hair. This could be used as a wrap deformer on the ear. That would allow better collisions and twisting behavior.