Hello everyone! Welcome back to my endlessly rambly Tips & Tricks article. As always, feel free to send feedback, suggestions, and complaints to tipsandtricks@animationmentor.com. Thanks to everyone who's been writing in, it's been fun meeting you, and I appreciate the suggestions and feedback! Thanks especially to those of you who've been sending me the fried chicken recipes!!! I think I have plenty now, so if you really need to send me a recipe for something, hit me with your favorite cocktail. (My current fave is vodka and 7up, but I also love a good Bacardi Anejo y Coca!)

Last month you discovered that you are a tool. I was sorry to have to break the news to you, but hopefully it softens the blow to know that I am a tool as well. This week, you'll be happy to know that I'm not going to be calling you any names at all! In fact, I have a bonafide "trick" for you, but first, let's go to Disneyland...

Okay, so my fiancée’s family has pretty much the coolest tradition ever: Each year, they spend the holiday of Thanksgiving in the happiest place on Earth - Disneyland! This year we were there for a few days, and it was an absolute blast. (Best rides: Indiana Jones, Screamin', and that Grizzly rapids ride in California Adventure!)

Anyway, it was a ton of fun, but since this isn't my diary or a blog, that's not why I bring it up. I brought it up because in California Adventure (the sister park to Disneyland, right next door), they have a building dedicated to the art of animation. Inside, you can walk through a museum of original animation art, you can put your voice to classic scenes from your favorite Disney movies (in our case, Belle and Beast ended up having a huge argument about flushing the toilet), you can create 2D animation and put it on a zoetrope, and you can interactively hang out with Crush from Nemo, which is basically someone doing live and instant performance animation and is pretty darn impressive to watch!

It's all pretty cool, and each of those exhibits branch off of a huge "lobby" area in the building. Inside of this lobby are gigantic screens showing scenes, drawings, and concept artwork from some of the best animated films of all time. Glen Keane's roughs from Tarzan, design work from The Incredibles, etc.

We didn't get to spend a whole lot of time in that room, but I have to say - I found it incredibly inspiring, and when I think back on our trip, it really sticks with me as a highlight. The permanence of our art really hit me in a big way. We create a scene, and once we're done, it exists forever. For better or worse, our great-great-great grandkids will likely be able to watch it and (hopefully) be entertained by it.

How cool is that!? Isn't it amazing to think that the team working on Jungle Book 40 years ago was just like us (only more talented), toiling away on their scenes, hoping someone might like their project? Hoping they might make someone laugh, or give a little kid that wide-eyed look of wonder at being presented with an army of singing monkeys? And here we are, 40 years later, still every bit as entertained and inspired as audiences were back then!

That's 40 years of inspiration. 40 years of laughs. 40 years of 3-year-olds mimicking King Louie's dance and making their parents laugh.

...40 years...

Maybe it's silly, but it really hit me in that room that no matter how trivial some of our work is, or how bad some of our projects turn out to be, we're all working towards nailing that one show or game or film that will be entertaining people long after we're gone. It's like we have a chance to not only inspire people, but to bottle that inspiration into a time-capsule, and launch it into the future to inspire future generations.

For me, THAT is inspiring, and as worthy a goal as any other. ...Well, okay -- other than curing Cancer, feeding the hungry, sheltering the homeless, ending poverty, etc. Those are the "Big Goals" with a capital G. I'm talking about wimpy artist goals, and we mostly use small g's. Making people think is about the best we can usually shoot for, but using media to get people to think can be a powerful tool, and we can be a part of it!

Okay, enough of that. Tip time! Are you ready?

*TIP #16: Constrain TO Props, Not To The Character!*

So, if you're animating characters, there's a decent chance that at some point, someone is going to ask your character to interact with something. He'll need to hold a broom, or she'll need to hold a sword, or whatever it is.

The natural inclination of the beginning animator is to constrain that prop to your character's hand, and then as you animate your character's hand, the prop will go along with it.

With some exceptions, this is generally a big mistake, and if you care about arcs at all, will often lead to some big headaches.

Now, I'm going to just assume that you're using IK (inverse kinematics) on the arms rather than FK (forward kinematics), even though I know that some of you probably DO use FK. Personally, I hate using FK on the arms, as I feel like it creates a lot of counter-animation work for me. I know some of you love it, but we'll just have to agree to disagree here.

If you really have to use FK on your arms, then you'll probably have to constrain the prop to your character's hand, and that's that. If so, you might as well save yourself some time and move along. Hopefully the Disneyland story was enough to feel like you didn't get ripped off this month, and I'll see ya next time!

Ok, you IKers still with me? Let's get back to our regularly scheduled program:

So.... why on Earth would it be a bad idea to constrain a prop to a hand?

Well, the biggest problems arise when you have a large or long prop.
Let's say it's a sword, for example.

If you constrain a sword to your character's hand, you will have a fine time blocking things in, and everything will be fine. At first. But if you are animating a sword, you know that you need to make sure that the tip of that sword is traveling along nice figure 8's and smooth swirling arcs (the only exception is when it makes contact with something. No matter what!), so after your blocking is done, you'll eventually need to go in there and track your arcs on the tip of that sword, right?

Well, if the sword movement is based on the rotation of your character's wrist, you've just created a big pile of unnecessary work for yourself.

Why?

Well, because every little rotation of your wrist will be magnified exponentially in the position of the tip of that sword. It's so far away from the wrist that a 5 degree rotation will suddenly have the tip of your sword a foot or more out of place! Editing this in a way that doesn't make the hand look stiff and/or jittery is very time-consuming.



Additionally, if you're using IK, the angle of wrist is very likely being affected by the translation of the elbow controller (or arm twist attribute), and is probably also subtly affected by the movement of the shoulders. Normally, this is great, and helps keep your animation feeling connected throughout the arms, but if you're trying to have finite control over the angle of the wrist, it can be a real bear to edit in the curves, because suddenly the angle of the wrist is being affected by 3 different things, and you're trying to fix curves on three objects that are all affecting each other! In other words, it's a pain in the butt!

A far better method is to switch those constraints around, and block things in where the sword is the thing being animated, and the arms are "along for the ride." You constrain the hand TO the sword, and THEN you dive into your blocking. Of course, you'll have to be vigilant to make sure that your timing and poses indicate the body and arms are moving the sword, and you'll have to be careful to avoid that "IK" look, as you would in any shot.

(uh oh - here comes a tangent:)

If you are new to IK in general, there will be a tendency for your animation to look like the wrist is moving the arm around, because that's the way the model is chained. Your job as the animator is to make sure that it looks like the shoulder is moving the arm, and the arm is moving the wrist - not the other way around. If you are doing proper planning, and have spent time focused on body mechanics (weight, force, anticipation, all that good stuff), then this shouldn't be much of a problem, and you'll be blocking in your key poses and breakdowns just as you would with FK.

In other words, a well animated FK scene should look EXACTLY like a well-animated IK scene, because both should be using the same poses and timing - you're simply using different controls to get them there.

Anyway, the point is, if you animate the prop rather than the hand, you will always have a far easier time creating nice organic arcs and a more pleasing realistic motion. You'll have far more control, and have to take much less aspirin during the polishing phase of your scene.

One caveat to that is if you have a small prop, such as a pencil or something that wouldn't take the strength of the wrist to move. In that case, I'd recommend constraining the pencil TO the hand, rather than the other way around. The fingers will be doing far more of the work, in that case, and the arcs of the pencil will likely have little to do with the arcs of the hand...

Okay, that's it. Have a great month, keep the emails comin' (tipsandtricks@animationmentor.com), and keep having FUN!!!!