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loked
01-11-2003, 10:21 PM
Hi,

I know how this is probably one of the biggest rigging challenges. So I figured it would be a good idea to put up a post where everyone shares their method of rigging a shoulder and mentions why they prefer that method. I personally use the rig that Jason Schleifer explains in his Alias|Wavefront DVD, but Id also like to see and hear other methods.

Hope to get a good response.
Cheers,
Loked

joie
01-12-2003, 02:15 PM
Hi!, I use a simple FK system when FK is switched in the arms, I mean I use FK in the clavicle joint, Iīve just played around to get that joint movement automated by some driven key or so, but I didnīt get the right way to do it..., may be itīs because I was using the arm rotation to drive it, but if the arm is in a IK system, all of its rotate axis get wrong, and my driven key with it! xD

Hope Iīve explained my self, and sorry for my english...

bentllama
01-13-2003, 08:47 AM
I usually use only FK-like controls for my shoulders...

...the only time I would use IK in the shoulder is for a creature with extreme movement in the shoulder [usually some quadripeds]

jschleifer
01-13-2003, 10:08 PM
In general I use fk controls for my bipedal characters, and ik controls for my quad characters.. for some reason, I find it easier to do quads with ik, don't know why. :)

the rig that's in the DVD has an automated shoulder setup which uses ik and works pretty well for just getting base motion, and then allows you to either animate on top of it, or turn it off all together.. it's a nice rig, but for some reason we just don't use it here. :)

cheers,
jason

mic
01-14-2003, 07:34 AM
I'm very new to rigging. And right now I'm completely stuck with the shoulders. They move nicely untill I go for the arms in the air pose, then the shoulders just does some really weird deforming. I've tried several hold bones but maybe I'm just doing it totally wrong.

It would be really great to see how some of you guys place your bones and how the mesh topology is like so maybe I have an idea of how a decent shoulder rig goes.

Thanks.

joie
01-14-2003, 08:39 AM
Receantly I had to animate a guy putting a helmet on his head (if you think about it you will get sick, itīs quasi-impossible!), after try different types of shoulder riggs, I realised that the best way to do it was to make a muscle-driven system, I think is the best way because if you want to put a helmet on your head you have to raise your arms and rotate them almos 180š, and this is a headache in many ways...

You can view the animation where this occurs in:

http://www.vortice3d.com/Espanol/CGIs3D/Entretenimiento/SeriesTV/Frameset.htm

The animation shows the guy putting his racing helmet on his head, itīs very fast, but it taked most of our time!, oh, what a sick thing, but, you know, the client is always right isnīt it?

:D

The animation is a mixture between Mocap and keyframing driven animation...

LFShade
01-14-2003, 01:46 PM
I find that up/down and forward/back rotations of the shoulder are easy enough to handle, but I've not yet found a good way to rig the shoulder so that it handles twist well. I always get horrible deformation when the arm twists past a few degrees! Anyone know of a good way to rig this in Max?

dwalden74
01-14-2003, 07:12 PM
it's a nice rig, but for some reason we just don't use it here.

Hi Jason-

I think that setup is good, BUT.... what I donīt like is that your IK arm (which is driving the "aim" and therefore the shoulder auto-orient) reaches its full length *before* the binding arm reaches its full length. This cause the auto-shoulder to stop all of a sudden. You know what I mean? Itīs obviously more noticeable when you reach to extreme positions (up and down, for example).

I havenīt tried animating with this technique yet, but I imagine it could cause strange unwanted twitches in the shoulder. Iīd like to find a solution for this.

What do you think?

:beer:
David

john_homer
01-14-2003, 08:40 PM
Hi,
sounds like you just want to "dampen" the joint when it gets to the min and max.. am I right??
well you could try using the "Joint Rotation Limit Damping"....

Or you could....
duplicate the "aim" joint. SDK the duplicate to copy the rotates of the "aim" joint by setting keys on the min and max rots. Then you have the SDK curves, you can flatten the tangents to stop the sudden stop. You can also tweek it so that for example the scapula goes up "easier" than down as the arm moves (as raising the arm past horizontal tends to be mostly scapula)
Obviously then the "duplicate aim" would drive the scapula ik.

hope this helps.
BTW: i havent actually tried this... just thought of it now.. but I dont see what it wouldn't work ;)
.j

dwalden74
01-15-2003, 02:27 PM
duplicate the "aim" joint. SDK the duplicate to copy the rotates of the "aim" joint by setting keys on the min and max rots. Then you have the SDK curves, you can flatten the tangents to stop the sudden stop

Yeah, I havenīt actually had time to look for solutions for this, but something like what you say may produce at least better results...

:beer:
David

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