Hi everybody (Translation in progress),
Often you can see works of students guilty of credibility for lack of knowledge or misinterpretation of forces.
All we have faced one day a famous criticism “Your animation is too floaty” O “Lacks weight, it seems that the character is under water!”
One of the biggest problems in the animation if placed in the correct interpretation of the body dynamics, so I think it is useful to understand the origin of this mechanical: Forces.
Those same forces define all: The times (Timing, Spacing) poses (Anticipation, Reaction, Balance, Squash/Stretch) and movements (Arcs, Overlap, Residual energy, Inertia, Action/Reaction, Slow in/out).
All the work of biomechanics is a direct response to the interpretation of the forces.
Gravitational force or gravity: Attractive force exerted on another mass, and affects all bodies. (For example, a character in the gravitational field of the earth is attracted to her)
Normal strength: Type contact force exerted by a surface on an object. This acts perpendicularly and outwardly from the surface. (For example, the thrust exerted by the ground on a character and prevents it go through)
Applied force or "Drag": External force acting directly on a body. (For example, a character pushing an object)
Friction Force: Contact force acting to oppose the sliding movement between surfaces. It acts parallel to the surface and opposite to the direction of sliding. (For example, the friction that produces ground on the soles of the feet of a character is different if the floor is dirt or ice)
Tensile Strength: State of a body subjected to the action of opposing forces that attract. (For example, the force that receives a rope being pulled by two characters)
Elastic force or "Spring": Physical ability of some objects change shape when a force acts on them deformation. An object has the ability to return to its original form when it stops the deformation. (For example, a rubber ball or subjected to an impact in other words, the very beginning of squash and stretch)
Force Push or "Thrust": Reaction force described quantitatively by Newton's third law and is based on action and reaction. (For example, the force exerted against a gun and that makes the reverse is exactly equal in magnitude to the force driven by the bullet.)
Downforce: Force suffered a body moving through the air, and in particular the component of the force in the direction of the relative velocity from the mean body. (For example, air resistance note character at high speed to go)
Buoyancy force or "upthrust": Also called "Buoyant Force" in English, It is the upward support force on an object immersed in a liquid (For example, the force that receives a character in water and allow to float)
Centrifugal force: Fictitious force that occurs when the motion of a body is described in a rotating reference frame. (For example, the force that perceives a character being in a wheel)
Magnetic Force: Interaction that occurs between electrically charged particles.(For example, attraction that receives a character dressed in armor to be near a giant magnet)
To fight all the forces, a character has these powers:
Anatomy and physiology: Joints and muscles that have a character (For example, in 4 fantastic, the thing morphology have a totally different man to the elastic displacement. Now I will comment more on this in the next article BODY DYNAMICS)
Personality and Psychology: Character of a character that will define his attitude which will determine its course of action and movement (For example, Bugs Bunny by very depressed that this will always travel faster and be more energetic than Droopy)
Mood (Mood): Reasons and motivations of a character when it comes to bring an action (For example, If a character is killed will cost much more to do any kind of action and fighting external forces if it were cheerful)
According to a classical definition, a force is any agent capable of modifying the amount of movement or shape of materials. Nothing moves without a force, your job is to understand why things move !
I hope that was usefull…