Rigging Help and Pipeline question

[KHALID]

hehe!!
Normal issue David, I think what you are referring too is the Chicken leg effect ;)


Well if It's that then you will have to start over in the... not from the beginning but from setting up your IKs in layout, load your object then ad the bones as you always would, then before you us IK with your motion option menu (M), Bend the knees of your character slightly the way it supposed too, then start rigging, This is a small trick that will help you a lot, the problem should be solved :)
Good luck,
k

[thirstydevil]

Thanks KHALID!

I'll try that at work tomorrow. Just so I understand you correctly. Setup the legs... Record Pivots and Rest Positions as normal. Then activate the bones. (all FK to this point) Rotate the characters legs then add the IK Nulls and IK as normal?

This does surgest that there is problems with the initial stat that the IK is in when you add the IK.

I've been playing for the evening with the rig and got it working by NOT using Tip and Joint move. I've done this 3 times now without using the new setup tools and got an almost perfect result. I've noticed that tip move will flip the rotaions 180 d's in heading and bank channels.

Perhaps this isn't the root of the problem but its another bad apple in this fruit bowel.

Thanks

-David

[KHALID]

hey!
Well you have to go threw this to get better ;) just don't give-up.

When you say rotate the leg...Hm!! sounds extreme, you don't want to bend a lot just a bit, another way of saying that (Knees Not Locked) If you have done any Karate or Kongfoo it would be the basic stance, bend knees stance...just the trick is to bend it where it bends.
good luck,
k

[T4D]

Sometime you'll see aflip even with good pre bending In that case put a rotation limit on the lower part of the leg problem gone :thumbsup:

[Remi]

Yep T4D has it...you can leave your IK on and just adjust the rotation limits on the shin bone in the pitch and you should be good to go.

[thirstydevil]

Well I'm going to try all your surgestions today at work. 9.30 here (UK) so I'll post my findings about 4pm. Hopefuly this will solve the problem.

Thanks again everyone. (Good to see the LW community is still the best)

-David

[thirstydevil]

:thumbsup:

I changed the default pose of the character to a bent knee (Half sitting position). Made sure the feet were in line with the knee and under the hips so the legs from the root bone to the toe bone would be in 1 plane only.

No popping what so ever everytime all the time...

Sure is silly... but heh it works.

I'm sure that the initial state that the IK is setup from is crutial to the accuracy. You should be able to setup any bind pose as long as you have some knee bend to tell the IK which direction to solve. Come on LW... please look deeper into the IK system. IKbooster is quirky, not what animators are used to. I thinks thats a massive bonus for XSI and Maya. There system is similar so all animators can jump from one to the next without problems. STOP! Rant over.

Now for FK IK Blending on the arms.

I may just have 2 rigs but FK/IK blending is what people are used to. Anyone have a good link for me?

PS Knee Up Vectors. Anyone done this properly. The Second IK Goal is a no no because it effects the foot goal. I know you can just grab the thigh bone but... agian animators are used to Maya and XSI and expect Up vectors. We'll just have to live without if it's not posible. I've seen it in the Expression builder...so I'll play with it in the mean time.

Thanks again people :applause:

-David

[T4D]

I may just have 2 rigs but FK/IK blending is what people are used to. Anyone have a good link for me?

FREE IK/FK Blending video for you (http://www.thomas4d.com/html/videos.html)


PS Knee Up Vectors. Anyone done this properly. The Second IK Goal is a no no because it effects the foot goal. I know you can just grab the thigh bone but... agian animators are used to Maya and XSI and expect Up vectors. We'll just have to live without if it's not posible. I've seen it in the Expression builder...so I'll play with it in the mean time.

Thanks again people :applause:

-David

make the leg a 2D IK chain ( eg only one channel on each bone controled by IK )
leg Hip IK Controls Bank channel
Upper and low legs Pitch controlled by IK
Now the heading on the Leg hip with give you great control over the knee placement:thumbsup:

[adrencg]

Limits don't really solve problems such as this...

All that will happen now is your joint will pop into the limit you've set. It may not go backwards al the way, but you'll still see a snap.

I copied this from another rig I found on the net, and it works great. Put a small bone between the thigh and calf which covers the kneecap. Give it a stiffness value of about 10, or whatever you need for the backward snapping to stop.

Mike

[thirstydevil]

adrencg

Yeah. Didn't work for me either. I'll play with your surgestion tonight. I remember seeing a web tutorial with a similar setup once. That may make all the difference. I'll let you know.

T4D

Thanks for the link... Great help!. Again I'll look into it as soon as possible and post the results.

-Thanks

Dave

[adrencg]

adrencg

Yeah. Didn't work for me either. I'll play with your surgestion tonight. I remember seeing a web tutorial with a similar setup once. That may make all the difference. I'll let you know.



By the way, this knee bone should have IK on for its pitch. In addition to keeping the leg stable, it also makes more volume in the knee for extreme bends...the calf is less likely to go through the bottom of the thigh during squats.

Mike

[T4D]

adrencg

Yeah. Didn't work for me either. I'll play with your surgestion tonight. I remember seeing a web tutorial with a similar setup once. That may make all the difference. I'll let you know.

T4D

Thanks for the link... Great help!. Again I'll look into it as soon as possible and post the results.

-Thanks

Dave

Glad the video etc helped :cool:


Well you got me stuffed :shrug:what are you doing to get flipping so bad

Prebending the joint is all that's needed Most time, the 10% of the time when Prebending isn't enough, a limit is all that's needed on the low part of the Ik chain.

I've Done CA on jobs where the rigs were done by other Lw guru rigger's and all i've seen used is prebending and limits and it works fine :curious:

Show us a pic please, you got me alittle Confussed as to what your doing




yes XSi does have alot more IK options But LW when you know what your doing works prefectly fine, you just have to pull away from the real complex stuff .

[thirstydevil]

T4D

I'll try to record what I'm doing and show you what results I get. The I'll record the fix I'm using and upload that videio as well.

It could be me... but it might not. I'v been using LW now everyday for 6 years. Altho I've always used other programs for Animation (ie PMG/MAYA). I have rigged Characters before in LW but they have all been FK rigs or simple none biped rigs.

I must stress that altho I do RIg characters, I only do this maybe 4 times a year (when the need occurs or demands). Rigging is something that you need to do often to remember how you did it last and how to improve it next time. LW has a very different method from other apps as well. Which is both refreshing at times and anoying some of the time.

Anyway. I'll post a vid of me rigging a bad leg setup. Also a good setup.

Again, your help (everyone) has been top notch.

-Dave

[T4D]

yeah i would be interested in what you find
I have to admit LW's IK isn't the best and some of the methods I uses cause i've done it so many times so I've forgot what special things i do.

I find when i rig in XSI I'm thinking with LW limits in mind and I don't need to worry about tho's things in XSI any more, so i have to re think with a more open mind....

[adrencg]

Did you try the knee bone trick? It works. Not to dispute what T4d advises -- he makes and sells a rig(I'm a customer myself) -- but I would say limits shouldn't be a fix for joint snapping. A few others have said this as well.

Even though my joints are prebent, I still get the "chicken leg" effect when the character goes into certain poses. The stiff knee joint always fixes it.

Mike

[T4D]

No Problem adrencg:D

Lw does have IK oddness it was the first thing i noticed in XSI I just couldn't get that flipping like i do in LW when i push it.

Tho i would like to know the problem
and I will remember your Knee bone trick adren for next time My method doesn't work :thumbsup:

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