How to Code Gravity in MakeCode Arcade

Have you ever wondered how to make your game characters jump, fall, or move realistically? Simulating gravity is key to creating engaging gameplay in Microsoft MakeCode Arcade. This guide will walk you through the process of coding gravity, ensuring your game behaves as expected.​

Whether you're coding for the simulator or MakeCode Arcade hardware devices, the gravity mechanics remain the same, allowing for smooth and natural movement.

To code gravity in MakeCode Arcade, set vertical acceleration to make sprites fall. Use a tile map for ground collision. Detect contact to prevent falling through. Add jump mechanics by applying upward velocity when a button is pressed. Adjust acceleration and velocity values to create a smooth and controlled movement experience.

Let’s understand that in detail:

Understanding Gravity in Games

Gravity is the force that pulls objects toward the ground. In video games, simulating gravity means applying a downward acceleration to game characters or objects, making them fall or jump realistically. In MakeCode Arcade, this is achieved by adjusting the vertical acceleration (ay) of sprites.​

Setting Up Your MakeCode Arcade Project

1. Create a New Project: Open MakeCode Arcade and start a new project.​

2. Add a Player Sprite: Initialize your main character using the sprites.create function.​

3. Position the Sprite: Set the initial position of your sprite on the screen.​

Implementing Gravity

To simulate gravity, you'll apply a constant downward acceleration to the sprite.​

1. Set Vertical Acceleration: Assign a positive value to the sprite's ay property to represent downward acceleration.​ This value determines how quickly the sprite accelerates downward. Higher values result in faster falls, while lower values create a gentler descent.

2. Limit Vertical Speed: To prevent the sprite from falling too fast, set a terminal velocity by checking and capping the vy (vertical velocity) in the game update loop.​This ensures the sprite doesn't exceed a realistic falling speed.

 

Creating a Ground Platform

For gravity to have a noticeable effect, your sprite needs a surface to land on.​

1. Design the Tilemap: Use the tilemap editor to create a ground platform.​

2. Set Tilemap: Apply the tilemap to your game.​

Replace the 1s with the tile representing the ground in your tilemap.

3. Define Ground Tiles: Mark the ground tiles as wall tiles to enable collision detection.​

The true parameter sets the tile as a wall, enabling collision detection.

Handling Collisions

To prevent the sprite from falling through the ground, implement collision detection.​

1. Stop Falling on Collision: When the sprite overlaps a wall (ground tile), set its vertical velocity to zero and position it just above the ground.​

This ensures the sprite lands properly and doesn't sink into the ground.

 

Implementing Jumping

To allow the sprite to jump, you'll need to apply an upward velocity when a jump input is detected.​

1. Detect Jump Input: Use a controller event to detect when the jump button (e.g., A button) is pressed.​

The condition if (player.vy == 0) ensures the sprite can only jump when it's on the ground, preventing double jumps.

2. Adjust Jump Height: Modify the negative value assigned to player.vy to control the jump height. A larger negative value results in a higher jump.

Adding Horizontal Movement

To enable the player to move left and right, apply velocity to the sprite based on button inputs.

1. Set Left and Right Controls: In MakeCode Arcade, movement is controlled using velocity. Assign a speed value when pressing left or right and reset it when released. This ensures smooth movement.

2. Adjust Speed: The higher the value, the faster the movement. A lower value makes the movement feel more controlled.

 

Refining Gravity and Physics

To enhance realism, fine-tune gravity settings:

• Friction: This helps prevent the player from sliding when movement stops. Adjusting friction improves overall control.

• Jump Control: In a platformer, jumping should feel natural. Gravity should pull the character down naturally, and jumps should be controlled by button presses.

• Double Jump (Optional): Some games allow a second jump while mid-air. This is useful for increasing difficulty and flexibility in gameplay.

 

Optimizing Performance

• Limit Frame Rate: A steady frame rate ensures smooth gameplay.

• Reduce Collision Checks: Too many calculations can slow down the game. Only check for necessary collisions.

• Use Efficient Sprites: Large, high-resolution images can slow down performance, so optimize sprite sizes.

 

Final Thoughts

By applying these gravity mechanics in MakeCode Arcade, you create a more dynamic and realistic platformer game. Adjust values as needed to achieve the desired gameplay feel. With these techniques, you can develop engaging games with jumping, falling, and smooth movement mechanics!