Game engines
A game engine is a set of tools in one program that helps people make games and simulations. Some well-known engines are Unity, Unreal and Godot. You do not need to know their names; you need to know the ideas.
- Objects: everything in the game (ground, ball, player). Each has a position, size and colour, stored as numbers.
- Physics: rules like gravity and bounce that move objects in a believable way.
- Camera: decides which part of the world you see and from where.
- Input: your taps, keys or controller moves.
- Rendering: drawing the picture on the screen.
The game loop: how motion appears
A game is not a film. It does not play stored pictures. Instead it draws every picture fresh. It repeats this loop:
- Input: read what the player did.
- Update (rules): move objects using physics and game rules.
- Draw: render the new picture.
Each picture is a frame. How many frames are drawn each second is the frame rate (fps). 30 fps looks smooth, 60 fps looks smoother. At 30 fps one frame lasts about 1/30 of a second.
Virtual sport scenes
A virtual sport scene is a digital court, track or pitch where players and a ball follow the rules of a real sport. Games, training tools and TV graphics use them.
- Build the field: court size, goal posts and lines made as objects.
- Add rules: gravity, bounce, how fast the ball slows down, scoring.
- Choose cameras: behind the player (like the player sees), above (like a coach), side (like TV).
- Use it well: train for safe practice, replay a match from any angle, or play with friends far away. Sleep, exercise and real play still matter, so balance screen time.
Try it
Use the sliders in the scene: set power high and angle low, kick, then set power low and angle high. Predict first where the ball will land, then check. Which angle goes farthest? Try a middle angle too.
Key formulas and definitions
- Game loop = input → rules (update) → draw
- Frame rate = frames per second (fps)
- Total frames = fps × seconds
- Objects = position + size + colour, stored as numbers
- Gravity pulls things down; bounce gives back some speed
Worked examples
1. A game runs at 30 fps for 10 seconds. How many frames are drawn?
30 × 10 = 300 frames.
2. How long does one frame last at 60 fps?
1 ÷ 60 ≈ 0.0167 s, about 17 milliseconds.
3. Which camera suits a coach reviewing team shape and why?
Above. It shows where every player stands on the whole court.
4. Name the three jobs in one pass of the loop.
Read input, update objects by the rules, draw the new frame.
Common mistakes
- Thinking a game plays stored video. It draws each frame live.
- Forgetting that every object is only numbers until it is drawn.
- Believing a bigger power always sends the ball farthest. Angle matters too.
- Spending all day on virtual sport and skipping real exercise.