Jan 26, 2013

Animating Dogs, Part II: More Gaits, and Examples

This is a continuation of my earlier post on animating dogs.

The Trot

The trot is a rather quick gait, between a walk and a run.  It is notable in that the feet on each side of the dog move opposite each other.  That means, for example, when the right front leg is forward, the right back leg will be backward.  When the front leg is backward, the back leg is forward.  See the image below to understand what I mean:


It's important to see that there are 'flying' stages, in which no feet are on the ground.  These happen, in the picture above, at frames 1 and 7 (or possibly 6, since 7 appears to have one foot touching the ground).

Another way to think of the trot is as a 'symmetrical gait' (which is how it's actually defined), where the diagonally opposing limbs of an animals body (e.g. right front/left rear or left front/right rear) move together.  This means that when the right front is going forward, the left rear is doing the exact same thing.  Timing-wise, they are almost identical, but the rear feet move a little more quickly than the front, meaning that the rear feet will hit the ground about one frame before the front feet, and they will lift up about one frame before the front feet as well.

Each side's cycle will take about 6-8 frames, so the full cycle will be 12-16, or about the amount of time of a fast human walk.

The Gallop/Run


This Edward Muybridge sequence is excellent for showing a typical dog run cycle.  A dog's run, like most animals, is notable for two things: (1) the very long period of suspension, where all legs are off the ground and (2) the compression and expansion of the spine.

In a dog's run, the head generally leads, and in many ways, the feel of the run is that the head is pulling the entire rest of the body forward.  Notice, for example, in the image above, how the neck between the first frame and the second goes from compressed to extended.  It remains extended until the next to last frame of the cycle.  The shoulders follow suit, extending fully by the third frame (notice how straight the back is at that point), and the hips follow about one frame later.

The spine is fully compressed on the last frame of the row (6) and full extended on the third.  When compressed, the head to the spine forms a beautiful S-curve, and when extended, it forms a very shallow, almost linear reverse-S curve.  It's this reversal of curves that gives the the run energy.

The hips are at their highest point on the next-to-last frame (immediately before the compression).  They are at their lowest on the second frame.  The shoulders are almost the opposite, at their highest on the third frame and their lowest on the fifth (when the hips are at their highest).

Now, to the legs.  In a run, the front and rear legs work in slightly offset pairs, more similar to a bound, like a squirrel:


For a small mammal like a squirrel, the front and back legs will almost be in total sync.  Both front legs will lift up and fall together.  Both back legs will do the same.  For a dog, the general movement is similar, but the timing is a little asymmetrical.

First look at the dog's back legs in the Muybridge series, since they provide the real 'power' to the run. You'll see that the legs lift off the ground one frame apart.  In this case, the left rear leg lifts off slightly before the right.  The two then travel through the air together, and the left rear contacts the ground just before the right.  The difference in that one frame, however, is enough for the legs to be very far apart when they push off again.  Notice in the first frame of the first row how far the legs, which only a frame before (frame 6, the last in the row) were almost symmetrical.  The same is true of the front legs.  The right front leg lifts off just before the left one, then they travel through the air almost symmetrically (with the left trailing slightly behind).  The right one then hits the ground one frame before the left, but in that time, they move very far apart from each other, forming a triangle-shape from the side.

Timing-wise, you can see that there is only about one frame of suspension.  The front legs touch down first, followed by the back, but by the time the back legs have hit the ground, the front are already in the air again.  As a general rule, each foot only touches the ground for about one frame, and none of them at the same time.

The whole run ultimately follows the pattern (based on foot touching the ground on each frame):

  1. RF
  2. LF
  3. compressed spine suspension (no legs touching the ground)
  4. LR
  5. RR
  6. extended spine suspension (no legs touching the ground).


Putting it all Together: Other Dog Moves with Examples from the Past

That about covers, very briefly, the basic gaits of a dog.  Naturally, there is more detail I left out, and endless variations.  We'll explore some of those variations below.

Like any animated character, the most important thing you can have isn't simply proper movements, but character.  Any animated dog should have a personality, readily identifiable by how s/he moves.  As you'll see below, the way Perdita (101 Dalmatians) moves is radically different from, say, Trusty (Lady and the Tramp), which is totally different from Dug (Up).

For each character, I'll explain what makes them unique and show how that uniqueness is expressed by his/her movements.

Side note: You'll notice that all my examples are Disney/Pixar.  That's both because they have done so many animated dogs and because they do them with a strict eye toward realism.  For cartoonier dogs (but still dog-like), check out Warner Bros. or Astro from The Jetsons or Scooby Doo or Odie from Garfield or even Disney's own Pluto.  For totally human-like dogs, which are effectively animated as bipedal humans with dog faces, check out Goofy, Brian from Family Guy, Snoopy from Peanuts, Wile E. Coyote, Gromit, or Underdog.

101 Dalmatians

Pongo

Pongo's character is, first, that of the bachelor dog, and then, that of the consummate dad trying to rescue his kids.  What's wonderful is how you can see the change in his demeanor throughout the film.  It's subtle, but substantial, and very personal.  Pongo is a dog's version of the everyman; thrust into a situation in which he must first save his children, then agree to adopt and save many others, he answers the challenge, but changes from a boy to a man (or, in this case, a pup to a dog).  For example, watch this clip, where he first woos Perdita, and notice how puppy-like he is.  The bachelor's life is carefree and easy, without a worry, and all fun and romance.  Pongo is full of energy:


As an animator, you can see the poses which show off his excitable young self.





However, in his role of dad, he's protective and careful.  Still, clearly, energetic, but very determined and duty-bound.  In the next clip, you can see how restrained he is now.  His focus is no longer finding a wife and having fun, but instead it is being responsible for ninety-nine puppies.  You can see him count them, encourage the little ones, then pick up Lucky, the straggler.  He then runs ahead, with a burst of necessary energy to tell Perdita that they should turn around and head to the dairy barn.  Finally, when he's in the barn, you see the wear the ordeal is taking on him.  No longer is he the puppy he used to be.


His movements throughout demonstrate how his character changes.

Perdita

Perdita, similar to Pongo, is kind of the 'everymom' (at least the everymom of the 1960's).  She's feminine and dainty, but also protective and determined, like Pongo.  Her character, in the film, is more of a supporting role.  She's the one who hates Cruella; she's the one who can outwardly sob and fear for her puppies; she and Pongo together can care for them.

Notice how dainty her walk cycle is.  I just love it.  Everything about both she and Anita says that they are reasonably upper-crust and very proper.  The juxtaposition of them versus flailing, uncontained Pongo and Roger is striking.



Colonel

I love the Colonel (reading a children's version of the story was when I first learned how 'colonel' isn't spelled 'kernel').


The Colonel is big and old.  He's hairy and slow-moving.  He's the consummate old military bureaucrat.

I didn't find a good clip of him moving that didn't cut off quickly, but what I have gives you some idea of his gait.  The important thing to remember is that he lumbers.  The Colonel doesn't move if he doesn't have to.  He also doesn't stick his head where it doesn't need to be.  In that way, he's the exact opposite of energetic, quick Pongo.  When he turns to run, his heavy mass gives him a very slow acceleration.



Puppies

The film, obviously, is full of puppies, so no is as good a time as any to talk about how puppies move. Like any young thing, you need to keep in mind the sizes of their various extremities and how that will change their gaits.

Generally, puppies move like normal dogs.  Their walk and run sequences are broadly the same, in terms of what moves at what time.  However, to get the characteristics of 'puppy' you can do a few things.

What makes a puppy a puppy?  They are smaller than their adult selves, with relatively bigger paws, bigger heads, bigger ears, and bigger eyes.  They're also a bit chubbier than when they grow up.  And, because they are young, they are far less sure (or overly sure) in their movements, meaning that their walks are either more shaky and deliberate (so, slower) or far more exuberant and bouncy, depending on the mood.  All of these give great opportunities for personality.

Here, for example, is a clip of Patch trying to be brave, but then being scared away.  Notice how as he barks, his entire body jumps up.  There's a full-body effect to everything a puppy does.  As he runs, his feet rotate all over the place, then as he runs into the corner, he lacks control over his weight and slides across the floor.  Also, notice the big ears, and the beautiful overlapping that happens throughout.


Another simple 'puppy' movement, is, during the walk cycle, to have the feet come up much higher.  To an extent, this will happen naturally, since puppy feet are so much bigger than in dogs.  But, like a young child walking, where their knees go up unnecessarily high, a puppy will lift its feet extra high to clear the ground, like in this clip, of an adorable puppy trying to walk on a treadmill (also note how his much his tail wags, and how it rotates his entire hindquarters; that's a very 'puppy thing'):


When a puppy runs, it bounds more than a dog.  That is, it's body goes up a lot higher and at a bigger angle.  Instead of remaining effectively horizontal, the entire body goes up at a 45 degree angle and then down.  Below is a run cycle copied from The Illusion of Life, based on Copper the hound from The Fox and the Hound.  Notice the angle of the body and the extreme angles of the spine (and how the head angles a lot between figure 1 and figure 7...in a dog, that would be far less of an angle).


Lady and the Tramp

Lady

Lady is a small breed, called a Cocker Spaniel.  Here's a bit of an intro to the breed:


Because Lady is a small and long-haired, big-eared dog, she isn't quite as nimble as, say Perdita, even while remaining very feminine in character.  She walks slowly and deliberately and keeps her head up, so to keep her ears from swiping the ground.  From the video above, you can see that Cockers have very active tails.  Because of their low center of gravity, they can also stand on their haunches fairly easily.  Both of these things are demonstrated here, when Lady first meets Darling's new baby:


As Lady gets older, she does a lot of trotting, which we looked at before.  In this way, it's used to add character, making Lady a little pompous, showing off her new license.


Tramp

There's not much to say about the Tramp.  He moves very, very similarly to Pongo (especially young, bachelor Pongo).  His face is obviously hairier, and his ears are bouncier because they're held up on his head, but beyond that, almost everything he does is that of a basic, medium-sized, thin dog.

You can see from this model sheet that the Tramp's main feature is his very expressive face (of course, without good body animation, that doesn't matter!), but look at his expressions:


Jacques and Trusty

Jacques (or 'Jock'...not quite sure how it's actually spelled) is a Scottish Terrier, and he moves very similarly to Lady, though even smaller.  It's interesting to notice that, while he's about the size of one of the Dalmatian puppies in 101 Dalmatians, he walks with much more surety and fluidity than the pups.  His walk is quick-stepped, with low, sweeping feet.

Trusty the bloodhound, on the other hand, is big and gangly.  He has big feet, saggy skin, floppy ears, and long legs.  Whereas Jacques almost floats when he walks, Trusty seems to almost flop.  Like a puppy, his feet are so big that he must lift them higher for each step.  This results in a lot of bounce in his hips and shoulders.  Also, due to his age and nature as a tracking dog, he generally keeps his head very low, unlike Lady, who holds hers proudly aloft.  When Trusty sits, you can see how he usually holds his head far below his shoulders, while Jacques keeps his up, like Lady (see photo below).


The following clip demonstrates some great dog movements.  Beyond the gallop, like we discussed above, it shows off the sniffing/tracking that dogs are known for.  Trusty keeps his face firmly planted to the ground, as he quickly walks.  His head sweeps back and forth, being sure not to miss anything.  His sniffing nose takes three frames to get to its maximum height, then two to return to the ground

As they run, you can also see how flexible Trusty's long spine is compared to Jacques's.  He bends a lot while running.

Finally, you can see at the end of the clip how Jacques howls.  Again, a very 'dog' thing.  This is a slow, mourning howl, but it follows a general pattern.  First, he sits down, while remaining bent, with his head down, forming a C-shaped arch with his body.  He then reverses that C-arch as he goes into the howl, pulling his head up, and arching his back, resulting, with the haunches still on ground, in an S-shaped curve.



The Fox and the Hound

Copper


I mentioned him earlier, in discussing puppies.  There's not much to say beyond that, but I'll add this video, possibly the sweetest clip Disney ever produced in any of its films. Notice how much character there is in Copper's huge, floppy ears and then in his howl. He stretches his little body as much as he can, splaying his toes, and almost falling backward. He's doing exactly what a puppy (or a kid), mimicking his elders would do:


Up

Dug

This is my final one.  I promise.  Dug is just so well done, I can't even handle it.  Beyond the movements that have already been shown, two things in particular (easily done in 3D, but harder to do in 2D) make Dug believable.

The first is Dug's eyebrows.  One of things that makes dogs so humanlike (and a reason, I think, that we feel so much more emotive towards them than to cats -- and this is coming from a cat person) is that they have very, very expressive eyebrows.  And the expressiveness is very similar to humans'.  For example, look at this growling dog.  The eyebrows, just like humans' are pulled into the middle, making the dog look angry:


On the other hand, when dogs are tired, or pouty, their eyebrows go up in the middle and down on the sides:


This technique is used really effectively on Dug.  For example, notice his eyebrows in this shot.  He's so clearly sad.  Add the darting eyes and the very submissive posture, and you have a very sad dog:


The other thing animators did for Dug was to give him a very dramatic tongue.  It's constantly hanging out, and, unlike most of the 2D dogs, it's hanging out to the side.  That little change gives a huge amount of personality, because it makes the dog come across as even more of a goofball than before (which is perfect for Dug's character).


Notice how effectively the tongue is used here (it moves his whole head!):


He also has a similar tail-wagging thing to a puppy, where his tail wags his entire body.  The character/realism combination that Pixar managed with him is, I believe, the best out there yet in terms of animated dogs.

Some other animated dogs you may want to use as reference:

Warner Bros. Bulldog - He's far more caricatured than the Disney dogs, but the guard-dog walk is just great.  Then, later, his tiptoe walk to keep the kitten from waking up.



Oliver and Company - The dogs in this film come in all shapes and sizes, from the tiny chihuahua, to the massive Great Dane.  Georgette the poodle is a wonderful character.


Birdbox Studio's puppy - I love this video.  There is so much life to this puppy!



All Dogs Go to Heaven - I've never been a huge fan of Don Bluth's animation style, but this is a worthwhile movie, with lots of great dog reference (Itchy the dachshund has a great character walk).


In Conclusion...

Like people, dogs have so many ways to move, and so many behaviors.  Every dog you meet will act differently.  However, like humans, there are basic cycles -- walk, run, and (non-human) trot.  By keeping those cycles, basic dog anatomy, and behavior in mind, you can create some amazing characters.  Check out Youtube, find some funny dog videos, and try to animate the antics that you see.  There are tons of them, and only by practicing the movements will you really understand how dogs carry their weight.  I'm still learning it myself, but am getting better every day.  You can too!  Happy animating!

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