Reverse Video Reference of Walking

The Laws of Physics in an Animation Universe

Boundin’ is a computer-animated short created by the animation studio, Pixar. It tells the story of a happy-go-lucky sheep that finds himself in unexpected circumstances, all set to the backdrop of the American prairie. The sheep finds wisdom from the mythical Jackalope and changes his outlook on life forever. The short is very light-hearted and whimsical and the physics in the film reflect those feelings. Characters in the film exaggerate the Action/Reaction rule to demonstrate a feeling of freedom. They also obtain unrealistic jump magnifications to instill that feeling in the audience. Although some rules are exaggerated, others are adhered to for the sense of believability. Timing and spacing rules are adhered to for the sake of demonstrating that the characters exist in a similar world to ours. Furthermore, the characters’ paths of action follow arcs, much in the way that things do in the real world.

According to the often-quoted Newton’s 3^rd law, for every action, there is an equal and opposite reaction. This law is also referred to as the “Action/Reaction” rule. In the case of the Jackalope, the “action” exerted is the character bouncing onto the ground. Every time he bounces, he is exerting force onto the surface of the ground. The “reaction” in the scenario arises from the ground. The ground exerts force back up into the Jackalope every time he lands and launches, propelling him up and outward. However, this is only part of a realistic jump. An important part of a character jump is the crouch. The crouch is a preparatory action that will aid in attaining a great height on the jump.When a character crouches, they will increase their push height, which will ultimately make their jump height a lot higher. In the Jackalope’s case, his crouch is virtually non-existent. Although he has almost no preparation for the jump, he is still able to attain a relatively high push height, and a jump magnification of 4.

Jackalope Jump:

The gophers in the short follow the same exaggerated rule. They have very little crouching action, but the air that they gain is disproportional. The greatest amount of squash that the gophers obtain is a slightly bent leg. They then launch themselves 1 body height into the air, and 3 body widths to the left and right.

Gopher Jump:

The sheep also follows the same exaggerated physics, but isn’t as severe of a “rule breaker”. As demonstrated, the sheep gives a considerable amount more squash than either the Jackalope of gophers. His torso can be seen tucked into his leg, which is bent. His body is lowered to the ground. Although he should gain some height, it shouldn’t be to the degree that is shown in the movie. He not only has a high apex, but the speed at which he moves is shown to be great, as is demonstrated by the almost constant motion blur. There are other instances, however, where the physics in Boundin’ adhere more closely to those found in the real world.

Sheep Jump:

In the animated short, there are various animal co-stars. Each character is depicted in an amusing manner, which contributes to the feeling and essence of the story. Although they are not portrayed in a realistic style, the characters are believable because their movements replicate (to some extent) those found in the real world. It is because of this “foot in reality” that the audience can forget the fact that they are looking at computer-generated images, and focus on the story unfolding before them. One area that demonstrates reality is the timing and spacing. In real world physics, when an object reaches a point near its apex, the ever-present gravity that pulls on the object starts to slow an object/character into its maximum height. The distance that the object moves in each frame significantly diminishes when it nears the apex. On the way down, the object slows out of the apex. Gravity is pulling the object down to the ground. The spacing between the character greatly increases during each frame. The owl quickly jumps out of his hole. Then, after gravity’s pull is too great, he slows into the apex. His stay at the apex is slightly exaggerated for comic timing, but is still believable. The owl then slows out of the apex, and starts a descent back to his home. The animation principle of squash is an important part of animating a jump or a fall, and is present in the owl’s movement. The first and last third of his trip up and down contains a motion blur. This shows that the owl’s movement is so fast at that point of the jump that he seems to stretch. The animators blurred the owl to obtain a more fluid animation. If it weren’t there, the animation would seem more static and would seem as though it was missing frames of animation.

Owl Timing:

The sheep is another character that has an exaggerated amount of time spent at its apex. Although the height of its jump and time spent in the air is exaggerated, the sheep’s jump is made believable by slowing into and out of the apex. This simple tweak of the physics contributes to the theme of the story. The Jackalope encourages the sheep to jump when he’s feeling down. This jump symbolizes the sheep’s feelings; when he’s feeling particularly melancholy, he should merely pick himself up and brush himself off. His long time spent in the apex shows that the sheep is capable of psychologically picking himself up and reclaiming a positive attitude. It also creates a feeling of weightlessness that the audience can feel as well.

Sheep Timing:

The fish in the water also slow in and out of their choreographed dance. This subtle movement continues to aid in the believability of the film. The fish move side to side in rhythm to the song. Instead of having a sudden, abrupt change of their paths, the slow into each extreme pose. The energy that propels them in one direction can’t suddenly and instantly be rerouted. The have to slow down into the pose, stop, and then build up momentum into the next pose. Typically, all things in nature follow an arc such as this, and there are further, clearer ideas in the short.

Another animation fundamental/physics law is the path of action. A path of action is the trajectory of an object. Nature dictates that objects will follow a parabolic arc when they move in various capacities, specifically, when gravity is the only force acting upon it. An arc is achieved because the horizontal movement is uniform while the vertical motion accelerates. This applies to not only broad movements, such as main bodies or large objects, but more specific things as well. Arm swings; leg movements, head turning and hip swaying can all be made more believable if they follow an arc. Characters in Boundin’ follow this principle. The actions such as the arcs and spacing and timing, are animated realistically so that the audiences attention won’t be placed up them. The audience, feeling that is placed in a believable world, concentrates on the motivation behind the character’s actions. The fish characters, although minor, contribute to this believability. Although the fish have teeth and smile, their actions are animated in a correct way. When they leap out of the water, the fish’s path of action follows a parabolic arc. Gravity is pulling on them, and once they reach a certain point, after the apex, they begin their descent back down into the water.

Fish Path of Action:

The Jackalope’s jump, although exaggerated in other aspects, is believable because it follows an arc. The gophers, who are imitating the Jackalope, follow a parabolic arc as well. There are 6 gophers that all move within a certain amount of time at each other. Their movements are staggered to avoid “twinning”. All of these characters, which vary in weight, height and overall muscle mass, have movements that follow a parabolic arc. It is their time in the air, however, that varies. The time in the air is directly related to how high their apex is. The Jackalope, who can attain a higher apex than either the fish or the gophers, can stay in air the longest.

Although certain physics boundaries are pushed on this film, they are done so for either comic timing or they contribute to the themes or feeling of the story. The creators of the short knew exactly what aspects of the story they wanted the audience to focus on. They animated aspects that should recede and have less weight more realistically. Pixar didn’t want the audience to concentrate on physics that didn’t seem believable. If they exaggerated in the incorrect place, the audience would focus their attention on trying to figure out what was odd about what they just viewed, instead of on the important parts of the story. By having believable physics where necessary, the audience can forget that they are looking at 0’s and 1’s on the screen. The audience will even believe that a mythical Prairie creature can, in fact, give advice a down-on-his-luck sheep.

The Laws of Physics in an Animation Universe

Physics in the Pixar Short, “Boundin’”

I. Introduction - A down-on-his-luck sheep finds sage-like wisdom in a mythical creature.

• a) Action/Reaction exaggeration
• b) Timing and Spacing
• c) Path of action (nature and gravity)
• d) Thesis statement

II. Action/Reaction exaggeration-Characters jump unbelievably high without preparation (crouching).

• a) Jackalope attains high altitude jump, without any kind of squash at the bottom of his fall.
• b) Gophers attain considerably lower altitude than Jackalope, but jump is still relatively high for the small amount of crouch presented.
• c) Sheep has a considerable amount more of squash than either Jackalope or Gophers, but is still disproportionate to the high apex of jump and time spent in the air.

III. Timing and Spacing - Characters slow in to and out from the apex of an action. It is exaggerated for comic timing.

• a) Owl jumps out of his hole. The speed near the bottom of the path upwards contains the principle of stretch, as demonstrated by the characters’ pose having a motion blur.
• b) Although the height of its jump and time spent in the air is exaggerated, the sheep’s jump is made believable by slowing into the apex, then slowing out of it.
• c) The fish swim back and forth in a synchronized dance. They slow in and out of each side as they move from once step to the next.

IV. Path of Action – Nature and Gravity dictates that objects follow a parabolic Arc.

• a) When the fish fly out of the water, they follow an arc. The fish is moving forward with continual spacing, but gravity is pulling the fish down exponentially.
• b) The Jackalope’s jump, although exaggerated in other aspects, retains believability because it follows an arc.
• c) The gophers, mimicking the Jackalope, jump into the air. Although in extreme perspective, we still see that they are following an arc.

V. Conclusion

• a) Laws of physics are greatly exaggerated in this short
• b) The actions are solid and are laws are bent to make certain aspects more endearing (realism vs. believability).

Stop Motion Animation of Falling

Stop-Motion Animation of Falling

This video was shot on 1's during the stretch. It seems a little fast, but I decided to include it.

Slow Motion of the Stop Motion

First, I decided right away that I wanted to do a stop motion animation involving me. I couldn't think of a more attractive and enthusiastic model to work with. I then began planning the Iron Man/Superman drop/flight by constructing a spacing chart that would create a believable fall from and flight back up to the apex. I then drew diagrams of what my body would look like during different phases of the drop.

I then enlisted my wife to start taking photos of me re-enacting the poses. Like this:

I then took the images into Photoshop and cleared all images of any background, leaving only me in the image, like this:

The image above has a motion blur applied to it to demonstrate speed and the animation principal of "stretch". I then used Photoshop to create the spacing guide and made 18 unique images. Those images were then imported into the animation software, Flipbook. I shot the animation on two's, and copied and pasted the clip so that it would repeat.