PDA

View Full Version : rotation-limit and soft-ik

CosmicBear
03-13-2003, 07:12 PM
hi guys,

i have an arm boned and set up with soft-ik. the arm is made out of three pieces (upper arm, lower arm, hand). my problem is thati want to limit the rotation of the lower arm-part to the y-axis. but when i set up 'rotation limit' in the soft-ik-tag, cinema is just ignoring me. all the parts are twisting in every direction. what am i doing wrong? or is it not possible? (i hope, i could describe my problem correctly)
LucentDreams
03-13-2003, 07:21 PM
this is a common issue what you should be doing rather than limiting the rotation is using what is called an upvector, refer to te manual and the mime tutorial to learn more about up vectors.
CosmicBear
03-13-2003, 07:31 PM
i basicly can sing the mime-tutorial by now http://www.cosmicbear.de/icons/wink.gif and i know of the advantage of upvectors. my problem is, that i need the limitation this time cuz the joints of the arm ask for it.
LucentDreams
03-13-2003, 07:35 PM
hmmm not sure I'm following, personally I'm not a big fan of constraining the character, constraining to me mean limiting. anyways, could you show a pic of what your trying to do?
CosmicBear
03-13-2003, 07:42 PM
here it is. sorry for the poor quality...
bobzilla
03-14-2003, 12:28 AM
Depending on what you're doing and how complicated the rest of your rig is, you might get away with FK instead of IK, and I don't see a need to use Soft IK in this instance. You might even try Set Driven keys with sliders, or in FK or IK, just rotate on the axis you want and not on the others.

Hope this helps...
JIII
03-14-2003, 02:07 AM
Cant you just click on what axes the arms should rotate in? I think this is in the AM bone settings.
wuensch
03-14-2003, 08:31 AM
--no matter if you like to constrain bones or not, you should be able to do so.
And his rig, although possible with different solutions, definitely needs constraint because of the mechanical part.
Plus maybe he only wants to add secondary motion via the dynamic?
I stumbled over the same problem when trying to constrain a shoulder bone.
Found no real solution, so I made the bone move via expresso.
But this is not how it should be.
Does anybody know if the rotational constraints do really work ?
Looks to me as if they dont.
Or I have been missing something important (which I assume)
Olli
CosmicBear
03-14-2003, 12:32 PM
Originally posted by Olli Wuensch

Does anybody know if the rotational constraints do really work ?

well, i have spent about 10 hours on rigging the arms and hands now and i couldn't get the rotation-limit to work in the way i wanted them to. so now the entire arm- and hand-rig is slider-based.
AdamT
03-14-2003, 03:15 PM
I've not had much luck with rotational constraints and SIK either, but it helps to lower the strength of the constraint. Of course that also reduces the effect of the constraint....
wuensch
03-14-2003, 03:58 PM
--hand is better via slider an FK anyway.
So it seems i am nt the onlyone who gave up on rotational limits--
Olli
That Adrian Guy
03-14-2003, 06:06 PM
It's so good knowing that I'm not alone.

The same problem happening to me is the reason I never animated that crazy cowboy. I'm almost sure I did everything right.

Oh well, I need to work on being a better modeller anyway.
CGTalk Moderation
01-14-2006, 03:00 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.