9. Game Physics: Simulating Realistic Movement and Interactions

Learning Objectives Explain what game physics is using their own words. Use variables to represent a character's position (x and y) on a screen. Write a simple algorithm to make a character move horizontally. Define gravity in a game and describe how it affects a character's vertical movement. Create a simple rule (an if-statement) to detect a collision with a wall. Describe the difference between position and velocity. Ever wonder why your character in a game falls down after a jump instead of floating away into space? 🚀 That's game physics at work! In this lesson, we'll learn about game physics, which are the secret rules that make games feel real. We will use variables and simple algorithms to control how characters move, fall, and bump into things....

TermDefinitionExample Game PhysicsThe set of rules in a game that control how objects move and interact. It's like the science of the game world.A rule that says 'if a character is in the air, pull it down' is a physics rule for gravity. PositionThe exact spot where an object is on the screen, usually measured with X (left/right) and Y (up/down) numbers.Our hero's position could be (x=50, y=100), which means 50 steps from the left edge and 100 steps from the bottom. VelocityHow fast and in what direction an object is moving. We can have velocity for X and Y movement.A car with an x_velocity of 5 is moving to the right 5 steps every second. GravityA make-believe force in our game that constantly pulls objects downwards.We can create gravity by always subtracting 1 from...

The Movement Rule new_position = current_position + velocity This is the most important rule for movement. In every frame of the game, you update the character's position by adding its current velocity. This creates smooth motion. The Simple Gravity Rule new_y_velocity = current_y_velocity - gravity_amount To make something fall, you constantly make its downward speed increase. We do this by subtracting a small, constant gravity amount from the character's y_velocity in each step of the game. The Wall Collision Rule IF character_x is GREATER THAN wall_position_x THEN stop_moving This is a simple algorithm using a condition. We check if the character's position has passed a certain point (the wall). If it has, we set its velocity to 0 to make it stop.