Chapter 85: Game Movement
1. The Basics: What Exactly Is Game Movement?
Game movement (aka locomotion or player traversal) is the system that controls how characters, vehicles, or objects change position and speed based on player input, physics, and game rules. It’s velocity in action—turning controller presses into smooth dashes across screens!
- Simple Definition: Input (WASD/stick) → acceleration → velocity → position update. Jump? Add upward vel + gravity pull.
- Key Job: Feels responsive/fun—precise for platformers, momentum-y for shooters. Ties everything: rotation (face direction), gravity (falls), bouncing (rebounds).
- Analogy: Hyderabad auto-rickshaw—throttle input → accel to 40km/h → zip through traffic. Sudden brake? Decel skid.
- Without It? Static pixels. With it? “One more run!” replays.
2 Types: Kinematic (direct pos set—snappy, no physics) vs. Physics-based (vel/accel/forces—realistic chaos).
2. Quick History: From Pong Slides to Momentum Masters
- 1970s:Pong—paddle slides left/right (constant speed).
- 1980s:Mario—accel ramps for “juicy” run-up.
- 1990s:Quake—air strafe/bunny hop (momentum skill).
- 2000s: Physics engines (Havok)—cars drift realistically.
- Now (2026): UE5 Chaos—procedural AI movement in open worlds.
3. Types of Game Movement: The Speed Spectrum (With Table)
Genres demand different feels! Table compares:
| Type | Feel (Simple) | Physics? | Input Style | Best For Games | Example |
|---|---|---|---|---|---|
| Platformer Accel | Slow start → top speed ramp | Light | D-pad/stick hold | Side-scroll jumps | Super Mario run-up
spriters-resource.com
Mario – Super Mario All-Stars: Super Mario Bros. 3 – SNES – The Spriters Resource
|
| FPS Momentum | Air strafe, bunny hop—chain speed | Full | WASD + mouse | Shooters | Quake/BGMI circle-strafe
 en.wikipedia.org
Strafing (video games) – Wikipedia
|
| Top-Down Constant | Steady walk, no ramp | None | Analog direction | RPG/explore | Zelda Link stroll
 youtube.com
Animating Link’s Walk | Recreating Zelda
|
| Racing Drift | Grip/ slide on turns, throttle accel | Heavy | Wheel/triggers | Sim racers | Forza tire screech
 forza.net
Drift Pony Cars on Sunset Peninsula in Forza Motorsport
|
| Flight/Thrust | Thrust vectors, no ground | Physics | Joystick throttle | Space sims | Kerbal rockets |
| Hybrid (Dash/Slide) | Bursts: dash, slide, grapple | Mix | Button combos | Battle royales/moderns | Apex tac-slide |
4. How Game Movement Actually Works: Physics Math (Step-by-Step)
Engines (Unity/Unreal) loop 60x/sec: Read input → Update vel → Move pos.
- Core Formulas:
- Velocity (speed + dir): vel += input_dir * accel * deltaTime (dt=0.016s)
- Clamp: if |vel| > max_speed → vel = max_speed * dir
- Friction/Decel: vel *= (1 – friction * dt) (slows when no input)
- Position: pos += vel * dt
- Ground/Air: Ground? Full accel. Air? 50% “control”.
Transparent Math Example (Mario Run: accel=50, max=10, friction=20): Start vel=0, hold right (input=1).
| Time (s) | Vel Update | Vel (clamped) | Pos Change | Total Pos |
|---|---|---|---|---|
| 0.0 | 0 + 50*0.016 = 0.8 | 0.8 | 0.013 | 0 |
| 0.1 | 0.8 + 50*0.016 = 1.6 | 1.6 | 0.13 | 0.14 |
| … | Ramp up… | … | … | … |
| 0.5 | Hits 10 (clamp) | 10 | 0.16 | ~2.5 |
| Release | 10 * (1-20*0.016) = 9.68 | 9.68 | 0.15 | +0.15 |
How to Arrive at Solution: Time to max_speed = max / accel = 10/50 = 0.2s. Distance to max = ½ accel t² = 0.550(0.2)² = 1 unit. Full curve (accel+decel): Symmetric parabola.
Air Strafe (Quake): Mouse yaw + A/D adds perpendicular vel—circle enemies!
5. Real Examples: Move Like a Pro!
- Mario Platformer: Accel feels “weighty”—tap=walk, hold=sprint. Skid stop on release.
- BGMI/Quake FPS: Strafe-jump chains speed (bunny hop: +15% per).
- Zelda Top-Down: Constant vel, rotate in place—explore chill.
- Forza Racing: Throttle=accel, countersteer=drift physics win corners.
6. Designer Secrets: “Juicy” Movement Tuning
- Feel Test: 100 runs—too slippery? Up friction. Floaty? Down air control.
- Root Motion: Anim drives vel (walk cycle feet push).
- Coyote Time: 0.1s grace jump post-edge.
- Cons: Lag=slidy; mobile=simplified.
7. The Future: 2030+ Movement
- AI Procedural: Gen custom dashes per player style.
- Neuralink Input: Think to strafe.
- Full Phys Sims: Every step procedural.
8. Your Challenge: Hyderabad “Auto Dash” Movement!
Design for rickshaw racer:
- Accel: Throttle ramp?
- Drift: Around Charminar?
- Top speed: 60km/h?
(Teacher’s: Accel=30, drift countersteer, boost dash!)
Movement = soul of games—master it, own leaderboards! Fave move (Mario sprint? BGMI slide?)? Next: “Game Collision”? Reply! 😎
Class in motion… dash back! 🎮💨
