A to B Walks

I am always asked about how to create an A to B walk cycle...by young animators, still learning. Are the animation schools just are not covering this? Do the schools only deal with walk cycles that move in place??? But, how do you get that moving forward in space? Right? I thought I would try and address it here.

I spent 6 years in games before crossing over into features. Video games are one of the best training grounds for an animator, because you are forced to do so many cycles over and over. In games you are expected to be economical with the frames (get the most bang for your buck) and end up sometimes keying on every frame to make the right arcs and motion. Not only do you have to be economical with frames, you have to be FAST! Producing upwards of 20 cycles a day sometimes. Finally, the day to day content of "punch-kick-run-die" is the best training in the mechanics of motion you can find - and perfect fodder for anyone wanting to work on one of those superhero movies one day!

I had a basketball coach in high school who used to say "If you don't do it right, we are gonna do it again!" Practice makes perfect and after years of doing cycles, you can start to have fun adding the personality to it...because creating the mechanics of motion will be as second nature as shooting that free throw shot.

For more on how to add personality to your walk cycles...check out the article on the thinkinganimation.com website here.

There are two ways to create an A to B cycle. In video games, creating a cycle in place and then translating a top node on the rig in Z is the defining way to get a character or creature moving through space. This process made it easier on the creature programmers to take the math of that top mode and pass it into the asset in the game and later adjust the timing of that translation according to how hard the player press on the buttons, etc.

You can also create the cycle translating the feet and center of gravity (COG) in Z. This means it would be more difficult to get the creature moving in a cycle in place, but I prefer this latter method if it's only one creature I am working on and I want to add more acting and natural bits to the cycle. I usually choose this method for feature work.

However, in commercials or with crowd sims it's easier to create the cycle as if you would for games and require the cycle to be in place with the translation all in the top node. This means as an animator, you need to know how to create both types of cycles. This makes you day easier since you have both approaches in your back pocket. Here, I will try an explain how "I" do these types of walk cycles.

This is my process, so take it for what it's worth. This is not rocket science and no one really showed me this trick, it's just something I developed over the years to get my cycles looking correct. The first thing I advise you to do is invest in some acetate and some dry erase markers. I buy the transparent acetate animation cels from cartoon Colour. Cartoon Colour is right behind Sony Imageworks in Culver City. You can just pop over there and pick some up. If you have a really big monitor you can buy the 3 Field Pan Size, but those are really expensive and I tend to just put more single field's up on the screen if I need them.

Dry Erase markers can be gotten at your local office supply store. The acetate enables you to draw on the screen without ruining today's advanced flat screen monitors. The old CRT's could take drawing directly on them because they were glass, but I find most studios have the flat screen now a days. Most people who have worked along side me know if my hands are covered in green, red and purple...I have been drawing on that screen all day trying to get my arcs, line of action or cycles down.

Moving onto the cycle.

Here is Redd the Clown walking in a cycle in place with no translation forward through space.

So, we need to get him moving through space at the right pacing.
I apply a Z translation curve to his top most node covering about 14 units.

But, when you play that movie back it's sliding in places...how do I fix that?

When you do the cycle in place, it's hard to account for the "controlled falling" that happens when a character or creature moves forward. The body has to absorb the planted foot and all of that weight, so there is a slight pause before gaining momentum and moving forward again. There are two ways to fix this. You can adjust the linear curve at the top frame by frame to keep each foot planted or adjust the Trans in Z on the feet. I prefer to keep that linear curve at the top clean and adjust the feet.

Here we go...get your acetate out and tape it to the screen and draw a line on the screen to guide where the tip of the toe is on the planted pose. If you don't have the acetate and dry erase...use the word "side" on your side view camera as a guide. Place the tip of the toe at the "S" in side to know where the toe should not move past.

Rising planted foot pose

Foot has slid just a bit past it's planted pose...
move it back on this frame.
Also needs to be moved up a little
so it doesn't penetrate the floor.

Now, the foot is too far back, slide it just a bit forward.
Go through frame by frame every step for the feet and make
sure they are sticking and planted where they should be.

You will have to do this for the front view as well after you have locked down the feet for the side view.

I hope this helped someone work out their cycles.
Below is the final walk cycle translating through space.

If you liked this little post, send some feedback in comments and I will try to do more of these. Every job I go one, there is a new animator trying to learn and I show them whatever tricks I have come up with for myself. I forget sometimes things I do that have just become second nature for me these days, so if you have questions about a specific problem...let me know and I will try to address it.
Cheers! Angie

P.S.

Micheal Sporn has some great walk cycles from 101 Dalmations broken down on his Blog.

Art Student Walking
French Girl and Poodle

p.s.s. for you baby bird...