Physics In Motion

5/11/14

Physics in motion

The focus of this project is to observe how objects move in relation to the laws of physics. Using some of the principles of animation, replicate real life physics and exaggerate motion to enhance expression.
I will be using stop motion to create the various movements in this projects. I will use cut out black card to make the shapes that i will animate and use white card as the background so my animation is clear and there is a contrast between the two so the audience can clearly see the movements i am making.
i will consider each caption beneath the exercise to estimate an appropriate motion (e.g. if it says the object is heavy or big).

Newtons Laws Of Motion:

I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.

II. The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector.

III. For every action there is an equal and opposite reaction.

when animation you need to consider what the material and nature of the subject matter is like:

. is it heavy?

. is it big?

. how springy is it?

. how smooth is its surface?

How Heavy Is It?:

Gravity affects speed. (increases when falling decreases when rising). 

Galileo (an Italian scientist and scholar that made pioneering observations in the 15 and 1600's, that laid out the foundation for modern physics and astronomy) proved that an objects weight does not affect its falling speed. But lighter, bigger objects are effect more by wind resistance.

This video of a man on the moon proves his theory correct:

                              

Weight (or mass) also effect inertia. Inertia is the resistance of any physical object to any change in its motion (including change in direction). In other words it is the tendency of objects to keep moving in a straight line at constant linear velocity. (e.g. a fast car turning a bend)

How Big Is It? 

if for example bounding balls (animated) move fast, it gives the appearance of them being small. If it bounces slowly it suggests it is large. This effect how close up the camera appears to be to the animated objects as the slow bouncing balls will look large but from a far away distance. 

Air resistance may come into play also e.g. a beachball or balloon with floating movements between bounces. 

How Springy Is It? 

Materials like rubber retain energy and bounce more. but so do hard objects like a ping pong ball on wooden flooring. the nature of the material should be decided before animating as there are also crumpling and soft materials to consider such as cars, plastercine and more that don't spring back into shape and therefore bounce less. 

How Smooth Is It?

Friction is the force resisting the relative motion of solid surfaces, fluid layers and material elements sliding against each other. An example of the is a bicycle slowing down when it moves from road to grass and even more so when it moves from grass to sticky mud. The grooves in the tire are making more contact with the mud etc and stick between the wheels. 

Animators look and work from these real world physics however they exaggerate them to amplify the effects. 

With out understanding the laws of physics, exaggeration in the wrong place can quickly dispel the illusion and can make uncomfortable viewing. Although it can be used as a comical effect and is seen in some cartoons:

                                

An Animated bouncing ball:

This diagram shows that animated bouncing balls will have vertical acceleration and deceleration, squash and stretch in parts of the bounce before and after it hits the ground. Its will also have successive lower and shorter bounces. The animation will also show the use of arc movements.

Diagrams showing the difference between real motion and an animated possibly cartoon motion:

The horizontal spacing is even between the real motion and varies in the animated motion. 

Here are some videos i made using stop motion to start to understand the laws of physics and how things move:

I then recreated some of the animations i made using after effects. The difference between the two methods are that i could go back and edit and alter the after effects animations where as the stop motion ones i would have to re do the whole thing. Also the after effects creation moved more smoothly and clear.