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View Full Version : multichain ik/fk rigs vs. maya ik/fk blend


lucille
08-12-2005, 04:37 PM
Hello--

Saw this issue on creature td with no real response. I will be doing a new set up today and
will post again over the week end. Meantime--are multi chain ik/fk set ups passe in
light of the ik/fk blend tools in maya?

JellyFire
08-12-2005, 09:16 PM
I'm only going off what I've read in CGToolKit's new rigging book, but they state that a multi chain IK/FK switch made yourself through set driven keys give you more control that the current FK/IK switch in Maya..

Later
Niietzshe

thematt
08-13-2005, 11:46 AM
I'm only going off what I've read in CGToolKit's new rigging book, but they state that a multi chain IK/FK switch made yourself through set driven keys give you more control that the current FK/IK switch in Maya..




ok I don't see why actually, they behave the same.
I've switch all my rig to that method now and it works great, plus it gives me the economy of 2 arm setup and ton's of driven key.
the switch can easilily be made too which is pretty cool.

Anyway that's only my point of view but so far i haven't see no real drawback from the ikBlend from maya.

cheers

Andrei2k
08-13-2005, 06:26 PM
There definitely are examples that you could look at where it breaks. Homer usually had a great one Ive seen him show...

lucille
08-13-2005, 07:09 PM
The key to getting this work like a normal rig is to turn on an attr "ikfkmanipulation"--
on the ikhandle--then you can use a point constrain to drive the chain like a standard rig.

In its default setting--you'll need to put a curve shape under the ikHandle--which means
you zero position will be non zero--not a big deal if you use a pose editor.

By default--ik and fk update automatically--which is good in some ways but awkward in
others.

pfj

thematt
08-14-2005, 07:19 PM
There definitely are examples that you could look at where it breaks. Homer usually had a great one Ive seen him show...



tell me more I'm curious about it.I've never made it break so I'm suprise...but i've breaked tons of time the 3 arm rig, which was mostly due to me not defining the right type of constraint interpolation

cheers

lucille
08-14-2005, 07:58 PM
I am switching over to the ikfk blend--but you can break it if you animate you pole vector
while also animating mode change. You can make it pop if you animate the pole vector
a sufficent distance. You really have to "try" to break it, though--it seems very robust.

john_homer
08-14-2005, 09:25 PM
I would say ikFkBlend is probably fine for arms, but not for legs/feet because of the multiple chains.. its hard to explain, but if anyone wants to send me a rig I'll be happy to break it in 2 secs ;)

the 3 joint setup can be broken too, but only if you really miss use it.

I recommend the 3 joints, and a simple script (which I can not supply ;( ) to match the ik and fk poses either side of the blend. I think I've seen one you can download... but would recommend writing you own if you can... for general customization of your needs ;)

.j

thematt
08-15-2005, 11:37 AM
I am switching over to the ikfk blend--but you can break it if you animate you pole vector
while also animating mode change. You can make it pop if you animate the pole vector
a sufficent distance. You really have to "try" to break it, though--it seems very robust.




oh yes right..that's why we're not using the pole vector thought it's easier to right a switch with it, i'll prefer just having animators using the twist attr..
I guess i've never had to do a rig so demanding that it breaks with the ikBlend, good for me.

As for writing the switch is pretty straight forward since the ik to Fk is already build, but still need a bit of customisation, and the Fk to ik is just a matter of rotating the bones so really simple...(for anyone who wants to take a look the attr are in the bones node..ik bones and fk bones.;just that I kind got stuck a few hours trying to figure it out.;hehe)

cheers

john_homer
08-15-2005, 09:10 PM
i'll prefer just having animators using the twist attr..

hi Matt, I'm really not trying to be rude or anything... :twisted:
but...
you actually get away with that??
they dont complain, swear.. throw things at you, plan to kill you in your sleep??

.j

thematt
08-16-2005, 07:23 AM
hi Matt, I'm really not trying to be rude or anything... :twisted:
but...
you actually get away with that??
they dont complain, swear.. throw things at you, plan to kill you in your sleep??




hehe..actally no, I make sur they don't animate in the same country as I am, plus they only know me as "the gost" that help..
:)

lucille
08-18-2005, 06:03 AM
This hasn't been a hugely popular thread--by I am undeterred. I did a leg set up today
with native ikBlend and it worked great. Its relatively simple and ez to script. If any notes
a problem--please post while I still pre production wiggle room...paul

john_homer
08-18-2005, 06:24 AM
... If any notes
a problem--please post while I still pre production wiggle room...paul

send it to me, and I'll send it back broken if you like ;)

.j

lucille
08-18-2005, 06:31 AM
Its a studio rig--I can't send it --can you comment on the problem?

john_homer
08-18-2005, 09:25 PM
so just send a leg, no geo required...
if the studio is too precious to send 5 joints rigged with a technique freely avalible then I cant help sorry I dont have the time to have a big "back and forth" about it, I've spent too many hours trying to explain stuff over the net and it sucks.
it doesn't break that often, only if the animator blends it "wrong"... just blame them
.j

darkjedi1929
08-19-2005, 02:57 AM
Hi Homer,

What do you mean by "breaking a rig"?

john_homer
08-19-2005, 07:31 AM
the joints will flip about as it blends from IK to FK rather than blending nice and smooth..

.j

Buexe
08-19-2005, 03:19 PM
most rigs that float around in the internet and even most of those "professional" studio rigs I have seen can be broken in about 1 homer unit ( ~5 seconds ). The IK/FK thing is only one issue, but certainly a big one and every time they said oh there is now a cool ik/fk blending solver i tried it and after about 2 homer units went back to business as usual. I prefer the "oldschool" method because it is very robust and gives you more opportunities, ie when you want to blend between sticky and non sticky and so on.
peace
~b

darkjedi1929
08-22-2005, 09:01 AM
Check out this tutorial:
http://www.dirtyoldtoon.com/tutorials/IKFKTutorial_01.htm
by Chris Fram

I tried it out myself, it works pretty damn well and best of all no additional attributes to key

Keilun
08-24-2005, 07:25 PM
Although not completely related, in Maya 7.0, there is another IK solver (ikSpringSolver) added to help ease the woes of multi-chain setups. It's targeted more at the insect/robot limb type setups. The goal of the solver is to have an even distribution of angular movement between all bones in the chain, hence its name. In addition you can add biases to the various angles of the chain to bias which bones move faster than others.

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