how to animate a moving armlet on a caracter ?


I’ve some issue to find a way to animate an armlet attached to the left arm of an armatured character.
I’d like it moves a bit and collides with the forearm during the main animation.

I’d tried things with game engine and rigid body then ipo conversion, but I didn’t obtain stable things… tried also the pivot constraint, but I’m not sure how it works.

I’ve also tried with kind-of rigid softbody but it’s not really great.

below is a test with a bracelet and a collision object (aka the hidden forearm…). I tested with the Game Engine :

anyone has an idea ? or perhaps something I missed in wiki ? sorry if that’s the case.
it’s strange how I find great ways to mix softbody, cloth or particle with armatured characters and how I’m stucked with rigid body.

this is for her, the armlet on her left forearm, which is tight for the moment…
help her please…

have you tried to setup a bone for the bracelet?
a bone thats connected to the upper-arm bone and
so you may be able to let it rotate a bit
and if you define a nla-action for this movement
it should be possible to add this whenever you need some eye-candy-movement
at this point (and it should always use the fixed relation to the position of the upper-arm-bone)

thanks, you’re right it’s certainly the best solution, to animate it by hand.
but I’m just curious about rigid body methods.

in fact, is it possible to calculate a rigid body animation without having
to bake ipo from the GameEngine ?

have you animated the cloth parts - those strips from the hands to the shoulders?

  • i never tried it, so this is only an idea:
    there is something linke “stiffness” for a cloth in the cloth settings.
    Imaging a cloth very, very stiff - it wont change its shape,
    but i think it would still move following the earth-gravitation.
    If you make it like a ring and it can slide up and down, then
    it should slide in the direction the the arm is held up - or the arm is put down.

the backdraw of all this things like cloth, hair, etc. is for every time the animation
gets changed later, the whole calculation has to be done again
for cloth there is a setting “clear cache from frameposition…”, thats new in svn version.

I think all the game engine can do for rigid bodies are convex shapes so you can’t do it that way but you might be able to fake it

I face similar problem… I couldn’t find good solution for rigid body simulations. Soft body with stiffness is useful but it’s killing mashine’s resourses during calculations. If someone has a nice solution me too would apreciate it.

yes, these are 2 softbodies attached to the top, that follows the pinky of each hand.

in fact I tried to do some rigid-body with the softbody : it works in simple case (a cube falling on a plane) but I’ didn’t manage te reproduce it in that case until now.

I’m doing some other tests, it’s still soft until now, at least I know how to setup rubber a,d bouncing things :cool:

I think I’ve something that (begin to) works :slight_smile:

Is that the best it can get?

I’m a newbie and I’ve been messing around with some of these features like game engine simulations and softbody stuff…

My results always seem to have this level of “Shottyness”(sp)
Why would it ever let the ring go through the pole? or fabric? or whatever?

Anyway, I want to know if you’ve figured this one out yet.

Is that the best it can get?
in fact blender is not a shop where you can get things, but a workshop where you can build your own things. with almost endless possibilities.
Blender is a really really great workshop where I go since 3 years, in which I found new things EVERY DAY ! :yes:
sometimes you’ve to search for a way for a particular thing, and wiki or google can’t help, so you’ve to do your own, and you always find something working (after a lot of tries and work…)
please also note that my first tries with softbody and complex things where frustrating at the beginning, as I didn’t know the basis of blender.

if you want to see things you can do with game engine :
there’s a great compilation of example files on that page.

you can also try ‘blender softbody’ or particule/animation on google or youtube.

in fact, the closed pipe tube won’t be rendered. it contains a king of ball which bounces into it. the armlet is parented to that ball, there’s no collision control between the armlet and the pipe.