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View Full Version : When playing animations, IK doesnt work o_O



TryForce
08-08-2007, 07:43 AM
when i animate with IK and later on i want to play the animation or go through the keyframes, the IK doesnt seem to be actived in that time.

any help?

thanks

j__
08-08-2007, 11:07 AM
Are you setting Full Time IK for the item at the end of the chain ?

is IK on ?

TryForce
08-08-2007, 12:03 PM
Hmmm, It got fixed by just reloading it.
thanks in anyway, though i had everything the same befor, also IK enable. (i used Lw8)

TryForce
08-08-2007, 02:16 PM
Ok, uhm I still dont get it, If i take a look at Timothy Albee's rigged stuff and his IK chains, they work smoothly animated withouth any "shocking", but my RIg has it, Here is a video of my tried walk anim:

http://youtube.com/watch?v=SEjWyeQkVFY

Can anybody tell me why i have this "shacking/shocking..whatever" or either help me how to fix it?

j__
08-08-2007, 09:02 PM
On your walk, in the legs, that's all it can do because your root or pelvis is too high relative to the IK on the legs in that circumstance, so all it can do is pop when it reaches a certain point. Similar with the arms, they have no way of knowing which way to solve for the animation you are doing with them.

It's a good idea to pre-bend the bones slightly before you apply IK to them, so it knows which way to solve the IK. In their rest pose have them bending slightly in the directions you expect the IK to solve those bones, so like slightly bent bones for legs and arms. But nonetheless, as the IK gets near the limits of where the bones are still bent and is suddenly taken out of those limits it will pop.

So the second thing is you may need more goals half-way up the chains; at the elbows and knees, and this will give you the control to stop the bones flicking direction.

All software is prone to flicking or popping IK if you try to do certain things with it, LW's is probably more flickery and jittery than everyone else's but you're doing fine with it.

Surrealist.
08-08-2007, 09:17 PM
Also if you have all the bending in order and even with your goals correct, you can get popping if you pull the goal to far in one direction at any given keyframe. It can wind up confusing the IK.

TryForce
08-08-2007, 09:22 PM
hmmm sounds like a need of rerigg, hehe.

Thanks guys,will do it more different this time.

So the IK aint that perfect huh? :-\

With what can i work easier then IK though?

j__
08-08-2007, 09:41 PM
It just takes some practice and feel to get it working more or less as you want it and you to have animate with its limitations in mind.

Surrealist.
08-09-2007, 12:29 AM
hmmm sounds like a need of rerigg, hehe.

Thanks guys,will do it more different this time.

So the IK aint that perfect huh? :-\

With what can i work easier then IK though?

Well, I would duplicate the way TA has it set up as a starting point. Go through the tutorials again. I've gone through the book a couple of times, always good.

IK is the ticket. You just have to understand how to use it - as stated above.

But there is also IK boost which is really cool. Do a search here for that after you get your rig working.

Also going through TA's animation exercises is a real good idea.

TryForce
08-09-2007, 01:12 AM
Well, I would duplicate the way TA has it set up as a starting point. Go through the tutorials again. I've gone through the book a couple of times, always good.

IK is the ticket. You just have to understand how to use it - as stated above.

But there is also IK boost which is really cool. Do a search here for that after you get your rig working.

Also going through TA's animation exercises is a real good idea.


Yeh I have been reading it last night again so im going to set up everything like TA did/does it. Just additionaly cloth and hair. although this time another character.

Although my main problem was i didnt finished just reading this book, i think because it made me to many problems, but now i luckly got into it.



It just takes some practice and feel to get it working more or less as you want it and you to have animate with its limitations in mind.

Yeh, i havnt learned Modeling in one night aswell =)

thanks guys :) as soon i will have a problem again be sure to check my thread ;P