DISQUS

parallelogramtastic · 6 months ago

While I agree that it is important to set a lot of breakdowns to make your animation convincing, I still prefer to animate arms in FK because it is a lot easier to see your arcs as you 'tween through your poses. It takes a lot of the guess work out of placing the next breakdown pose for an arc movement.

Hon Keat · 6 months ago

Do you have any tips regarding the ik elbow? I always have trouble with them. They like to zig zag wee wee waam!

CarrieChu · 6 months ago

I often have the same problem as Hon when animating with IK. Sometimes the elbow will go haywire and starts jerking in all directions.
Do you have any tips on using parent script to animate?
For example, using IK to animate the hand holding a fishing rod... ?

Arnie Mecham · 6 months ago

Awesome article Shawn! this topic just came up on the 11 second club forums.

Carrie, in one of Shawn's old posts he says that it can be helpful to constrain an IK hand to the object the character's holding (rather than having the hand control the object, have the object driving the characters hand)--- the reason being that if a characters holding something like a fishing rod or a sword, etc. you can control the arcs on the prop.
But like this article says, be sure to have all of the necessary poses in the computer to make it look like the hand's driving it and not the other way around.
If you need a parent script for Maya, I use zvParent or Parenting for Animators-- they both have easy "constraint on/off" buttons.

Richard · 6 months ago

I started out as recommended using FK on the arms. As you know rotations are hard to work with as it is, and having three sets of rotations (depending on how the limb is jointed) times three axis is something I decided I didn't want to deal with anymore. I would much rather translate something than rotate. I have been using IK now for everything. I so happen to key enough to where it doesn't effect my animation. I feel comfortable with my work-flow now.

For elbow flipping issue: On a new key I zero out (set values to zero in the channel editor) on IK wrist rotations and elbow twists, and then make sure I rotate them in the same order as the rotational order (Default for Euler coordinate system - usually x y z). It's my effort to help avoid flipping and Gimbal Lock.

Oswaldo G.C. · 6 months ago

Good article, always exist IK and FK trouble, by the moment I'm IK guy too (I hope always), thanx for share your opinion.

Jonas · 6 months ago

i'm just curious, what does "ik look" looks like? is there any example so i may know what to avoid?

FMaree · 6 months ago

I also hear voices from my 'puter! Easy solution is to turn the speakers off. :D

I switch between FK/IK for arms and legs as the situation needs it.

Dale Robinson · 6 months ago

IK, FK, Computers doing imnbetweens! Get a pencil and some paper, old skool style and all these problems dissapear!

Phil Willis · 6 months ago

I used to have a lot of problems with IK arms looking IK until I did:

1. Pose out the character with many more breakdowns and keys before you get to spline (as per Shawn's post).

2. Track the elbow using an arc tracker tool.

Number 2 was the bit missing - and until I did it I was having the same problem of elbows flipping out and looking crummy.

It's also especially important to really work the pole vector of the elbow if you want to get a good "successive breaking of joints" when you're using IK.

Get the elbow up to lead the hand up and get the elbow down to lead the hand down.

If you don't control the pole vector - it will control you and make your IK hands look IK.

Frank · 6 months ago

Another great post and good discussion. Thanks everyone. Planning, planning, planning.

Animation doesn't happen in the computer.

Here is something freaky the word verification for this post was 'poses'.