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Rabbitpenny
03-18-2009, 12:09 PM
Attached is a screenshot of a mock-up for dangling earrings I'm trying to animate. As you can see, it is a soft IK bone chain with 4 corresponding weight mapped componets. It gives nice motion but I'm stuck. Is there a way to have it follow the -y in a dampened fashion or do I have to keyframe the motion...

Or, more likely, am I approaching this wrong. Appreciate any help!

evenflcw
03-18-2009, 04:14 PM
You can make a null (or an other item for that matter) follow the points of the displaced mesh using Node Item Motion motion modifier and Point Info node by Denis Pontonnier.

http://pagesperso-orange.fr/dpont/plugins/nodes/Additionnal_Nodes_2.html

More on similar setups:
http://www.spinquad.com/forums/showthread.php?t=25031
http://www.newtek.com/forums/showthread.php?t=79042&highlight=node+item+motion


Another option would be to use IKBoost bone dynamics straight. But it is seldom as pretty as using Cloth_FX. Deform the earings like you would any other mesh, using 100% weightmaps for each part.

evenflcw
03-18-2009, 04:15 PM
Ahem... sorry. Just read a dynamics related thread before this one. You weren't using dynamics at all. :)

Any case, I'm abit confused about what you mean. But you sort of want to simulate the effect of gravity might have on the earing in a sortof adhoc way without using dynamics?

daforum
03-18-2009, 04:38 PM
Use clothFX and also make them collision objects so you can turn the head and they can bounce around without any problem of intersecting.

Rabbitpenny
03-18-2009, 06:50 PM
Thanks, Daforum. Suspected I was heading in wrong direction.

Rabbitpenny
03-19-2009, 07:54 AM
I'm abusing the good graces of this group, but once again...stuck. Cloth effects gives good motion except my object is not regarding gravity. See attached. This is, of course, my first attempt at dynamics, can't find a tutorial that matches what I need. Following Proton's basketball net tutorial...it works but the settings for the net are too compliant. When I make the material more rigid, I SEEM to lose respecting gravity.

Anyway, screenshots attached. Once again, thanks for any help.

evenflcw
03-19-2009, 12:44 PM
Stretch limit of 0 is seldom good. The solver usually works better if you give it some leeway. So always stay clear of the extremes, especially the extreme extremes (0). You can compensate for the stretching by overlapping the geometry instead. It will always stretch, but the stretching will increase with velocity. And at high velocities it's unlikely anyone will notice unless they scrub frame by frame. So just adapt the overlap to the idle pose.

Hold Structure should mainly only be used if you for example would like to keyframe the motion of a ball manually but use clothfx for deformation (upon collision). Hold Structure will pull all the verts back to their original position (ie, put springs between the dynamic position to the original position). You only want one fixed point for the earring, and the rest constrained only to that one point, so you shouldn't use it. It can be used to limit the deformation, but it's better to use other means.

Also don't use more segments than you got in your earring it contains rigid part and always try to use as little geometry as possible. First try polylines, then polystrips, last a 3d structure. If you need to limit bending then you might have to use polystrips or a 3d structure as the substructure option will put virtual edges/extra springs between close points, effectively making the structure more rigid.

See attached scene.

Rabbitpenny
03-19-2009, 02:38 PM
Dan,

Wow, just perfect! Thanks so much!
Dan Conforti

evenflcw
03-19-2009, 03:38 PM
Great! Your welcome!