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Physics for Animators

Book Description

Achieving believable motion in animation requires an understanding of physics that most of us missed out on in art school. Although animators often break the laws of physics for comedic or dramatic effect, you need to know which laws you’re breaking in order to make it work. And while large studios might be able to spend a lot of time and money testing different approaches or hiring a physics consultant, smaller studios and independent animators have no such luxury. This book takes the mystery out of physics tasks like character motion, light and shadow placement, explosions, ocean movement, and outer space scenes, making it easy to apply realistic physics to your work.

  • Physics concepts are explained in animator’s terms, relating concepts specifically to animation movement and appearance.
  • Complex mathematical concepts are broken down into clear steps you can follow to solve animation problems quickly and effectively.
  • Bonus companion website at www.physicsforanimators.com offers additional resources, including examples in movies and games, links to resources, and tips on using physics in your work.

Uniting theory and practice, author Michele Bousquet teaches animators how to swiftly and efficiently create scientifically accurate scenes and fix problem spots, and how and when to break the laws of physics. Ideal for everything from classical 2D animation to advanced CG special effects, this book provides animators with solutions that are simple, quick, and powerful.

Table of Contents

  1. Cover
  2. Title
  3. Copyright
  4. Contents
  5. Acknowledgements
  6. Foreword
  7. Introduction
  8. SECTION 1 CLASSICAL PHYSICS
    1. 1 Matter and Masses
      1. Matter
        1. Composition of Matter
        2. Atoms and Binding
          1. Nuclear Fusion
      2. Masses
        1. Mass vs. Weight
        2. Center of Mass
    2. 2 Motion and Timing
      1. Motion Lines and Paths
      2. Linear Motion
      3. Circular Motion
        1. Types of Circular Motion
        2. Rotational Motion
          1. Rotation and Distance
          2. Calculating the Number of Times a Wheel Turns
          3. Spinning, Tumbling, and Wobbling
        3. Centripetal Motion
          1. When Centripetal Force Stops
          2. Circular Speed
          3. Centrifugal Force
          4. Centripetal Force and Vehicles
        4. Pendulum Motion
      4. Wave Motion
        1. What Waves Do
        2. Visibility of Waves
        3. Types of Waves
          1. Transverse Waves
          2. Longitudinal Waves
        4. Wave Properties
          1. Wave Relations
          2. Wave Phase
          3. Wave Addition and Cancellation
          4. Standing Waves
        5. Common Sound Effects
          1. Resonance
          2. Doppler Effect
          3. Sonic Boom
      5. Timing
        1. Timing Tools
        2. Uniform Motion Timing
        3. Slow In and Slow Out
        4. Acceleration Timing
          1. Constant Forces
          2. Forces Exerted by Characters
          3. Constant Force and Acceleration
        5. The Odd Rule
          1. Odd Rule Multipliers
          2. Odd Rule Scenarios
        6. Motion Graphs
          1. Constant Speed
          2. Acceleration
          3. Acceleration of Gravity
          4. Swinging
    3. 3 Forces
      1. Components of Force
        1. Familiar and Unfamiliar Forces
          1. Familiar, Non-Random Forces
          2. Unfamiliar Forces
          3. Variable Forces
      2. Gravity
        1. Gravitational Acceleration
        2. Common Misconceptions about Gravity
        3. Timing for Gravity
        4. Calculating Total Time and Distance
        5. Physics-Based Calculations
        6. Visual Calculation Methods
          1. The Odd Rule
          2. Fourth Down at Half Time
          3. Falling à la Chai
        7. Moving and Falling
        8. Ascending Against Gravity
          1. Projectile Velocity
        9. Center of Gravity
          1. Line of Gravity
          2. Tipping and Center of Gravity
          3. Lowering and Raising the CG
      3. Friction
        1. Static and Kinetic Friction
        2. Friction on Flat Surfaces
        3. Frictionless Surfaces
        4. Coefficient of Friction
        5. Effects of Friction
      4. Pressure and Gases
        1. Pressure Increase from Heat
          1. Heated Gas in a Container
          2. Heated Air in Atmosphere
        2. Chemical Reaction
        3. Force from Pressure Decrease
        4. Atmospheric Pressure
          1. Air Resistance
          2. Aerodynamic Lift
          3. Pressure Differences in Action
      5. Torque
        1. Torque Basics
        2. Torque Terminology
        3. Maximizing Torque
          1. Visualizing Torque
          2. Calculating Torque
        4. Lever Systems
          1. Efficiency vs. Speed
          2. Neutral Efficiency
        5. Lever System Classes
          1. First Class Systems
          2. Second Class Levers
          3. Third Class Levers
        6. Balancing Torque in a Lever System
        7. Increasing Leverage
      6. Torque in Animation
        1. Rotational Inertia
      7. Action/Reaction
        1. Action/Reaction and Balanced Forces
        2. Action/Reaction with Two Mobile Objects
        3. Action/Reaction and Weight
        4. Action/Reaction and Fixed Objects
      8. Electricity and Magnetism
        1. Electricity
          1. Electrical Charge
          2. Static Electricity
          3. Flowing Electricity
          4. Electric Shock
          5. Sparks and Lightning
        2. Magnetism
          1. Magnetic Fields
        3. Visualizing Electricity and Magnetism
          1. Electric Shock
          2. Electric Current
          3. Magnetism
          4. EMPs
    4. 4 Light and Color
      1. Light Basics
        1. Light as Rays
        2. Light and Reflection
        3. Seeing in a Mirror
        4. Bouncing Light Rays
        5. Physically Based Lights
        6. Cast Shadows
          1. Umbra and Penumbra
          2. Sharp and Fuzzy Shadows
          3. Shadow Angle
          4. Light Source Shapes
          5. Shadow Intensity
        7. Form and Occlusion Shadows
      2. Reflection
        1. Specular Reflection
        2. Diffuse Reflection
          1. Diffuse Reflection and Light Intensity
          2. Detecting Shape and Color
        3. Diffuse vs. Specular Reflections
        4. Diffuse Interreflection
        5. Partial Reflections
        6. Refraction
        7. Caustics
      3. Gamma Correction
        1. Linear vs. Curved Light Intensity
          1. Gamma Correction for Real-World Perception
          2. Gamma Correction and Cameras
          3. Gamma Correction on Digital Files
        2. Gamma Calculations
          1. Monitor Gamma Adjustment
          2. RGB Gamma Curves
        3. Linear Workflow
  9. SECTION 2 CHARACTER DESIGN AND ANIMATION
    1. 5 Character Design
      1. Size and Scale
        1. Proportion and Scale
          1. Weight and Strength
        2. Physical Characteristics and Size
          1. Posture
          2. Deformability
          3. Wing Size and Shape
          4. Climate
          5. Longevity
          6. Sound
          7. Babyness
      2. Joints
        1. Types of Joints
          1. Animal Joints
        2. Joints as Levers
          1. Elbow
          2. Foot
          3. Neck
          4. Muscles for Joints
      3. Weight Distribution
        1. Character Center of Gravity
        2. Balance
          1. Improving Balance
    2. 6 Character Animation
      1. Jumping
        1. Parts of a Jump
        2. Calculating Jump Actions
        3. Calculating Jump Timing
          1. Jump Magnification
        4. Push Time
        5. Push Key Spacing
        6. Motion Arc and Jump Timing
        7. Landing
        8. Stop Time
        9. Very High Jumps
      2. Walking
        1. Poses
          1. Strides and Steps
          2. Walk Timing
          3. Walking and Energy Efficiency
        2. Hip Rotation
        3. Shoulder Rotation
      3. Dancing and Gymnastics
        1. Torque and Turning
        2. Balance with Multiple Characters
        3. Gymnastics Lever Systems
      4. Lifting Weight
        1. Shifting Body Weight
        2. Sitting and Standing
      5. Getting Hit
        1. Fight Scenes
        2. Momentum and Force of Impact
        3. Changing Momentum
          1. Force and Changing Momentum
          2. Action/Reaction and Changing Momentum
          3. Recoil
      6. Tipping Over
        1. Rotational Inertia and Tipping
        2. Tipping and Friction
      7. Drag and Follow Through
        1. Drag
        2. Follow Through
      8. Overlapping Action
        1. Length and Motion
        2. Surface Area and Motion
  10. SECTION 3 VISUAL EFFECTS
    1. 7 Environment
      1. Cloud
        1. What’s in a Cloud
        2. Types of Clouds
        3. Cloud Altitudes
        4. Inside a Cloud
        5. Movement of Clouds
        6. Cloud Effects
          1. Cloud Combinations
          2. God Rays
          3. Backlit Clouds
      2. Rain
        1. Rain Formation
          1. Types of Rain Clouds
          2. More about Rain Clouds
        2. Wind and Rain
        3. Where Rain Forms
          1. Predicting Rain
          2. Weather from the West
        4. Raindrops
          1. Falling Raindrops
          2. Invisible Raindrops: Puddle Effects
          3. Slow-Moving Raindrops: Windowpane
      3. Lightning
        1. How Lightning Forms
          1. Cloud-to-Cloud Lightning
          2. Lightning Formation and Appearance
        2. Effects from Lightning
      4. Thunder
    2. 8 Fire and Explosions
      1. Fire
        1. Flames
          1. Flame Appearance
          2. Creating Flames
        2. Smoldering Solid Matter
        3. Fireball
          1. Mushroom Clouds
          2. Mushroom Clouds in Animation
      2. Smoke
        1. Smoke Appearance
          1. Puffy Smoke
          2. Tendril Smoke
          3. Campfire Smoke
      3. Explosions
        1. Types of Explosions
        2. Life of an Explosion
          1. Before the Explosion
          2. After the Explosion
        3. Role of Containers
        4. Timing for Explosions
        5. Shockwaves
          1. Shockwaves through Air
          2. Shockwaves through the Ground
      4. Breakage and Fracture
        1. Anatomy of Fracture
        2. Crack Patterns
          1. Inherent Weak Points
          2. Internal Cracks
        3. Animating Breakage
          1. How Physics Engines Determine Fracture
          2. Flying Pieces
    3. 9 Liquid Effects
      1. Properties of Liquids
        1. Cohesion
        2. Adhesion
        3. Viscosity
          1. Newtonian and Non-Newtonian Fluids
          2. Solid/Liquid Behavior of Non-Newtonian Fluids
        4. Surface Tension
        5. Buoyancy
      2. Liquid Appearance
        1. Meniscus
        2. Pouring Shapes
      3. Oceans and Lakes
        1. Waves
          1. Wave Terminology
          2. How Ocean Waves Form
          3. Movement of Waves
          4. Breaking Waves
          5. Floating on a Wave
        2. Ocean and Lake Appearance
          1. Water Reflection
          2. Color of the Ocean
          3. Spray, Mist, and Foam
          4. Shadows on Water
    4. 10 Earth and Outer Space
      1. Earth Today
        1. Earth’s Layers
        2. Atmosphere
          1. Atmospheric Levels
          2. Height of Vehicles in Atmosphere
      2. Formation of Earth
        1. Gaseous Earth
        2. Supercontinents
        3. Formation of Modern Landscape
          1. Tectonic Shifts
          2. Volcanism
          3. Bombardment
          4. Erosion
          5. Glaciers
      3. Earth’s Crust
        1. What’s a Rock?
          1. How Rock Forms
          2. Rock Composition
          3. Rock Classification
        2. Causes of Geology
          1. Geology from Magma
          2. Geology from Compression
          3. Geology from Heat and Pressure
          4. Geology from Buoyancy
          5. Geology from Weathering and Erosion
      4. Designing a Landscape
        1. Usual Rock Colors
        2. Unusual Rock Colors
      5. Life on Earth
        1. Fossils
        2. Meteorites and Life on Earth
        3. Evolution and Diversity
      6. Outer Space
        1. Origin of the Universe
        2. Stars
        3. Galaxies
          1. Properties of Galaxies
        4. Nebulas
        5. The Vacuum of Outer Space
          1. Temperature in a Vacuum
          2. Sound in a Vacuum
        6. Radiation
  11. Index