How to build a controllable ball in Godot?
Creating motion dynamics for your characters and objects is essential to develop an interactive and engaging game. In this tutorial, I will guide you on how to bring a ball to life in Godot using a 2D Kinematic Body. Through these steps, you will be able to control and direct the ball in your game.
What are 2D Kinematic Body nodes?
Kinematic Body 2D nodes allow you to have full control over objects, as they are not affected by external physics such as forces or shocks. This is especially useful for objects that require precise control, like our ball in this example.
- Why use Kinematic Body?
- Absolute control without influence of external physics.
- Allows to steer the ball as desired.
- Avoids unexpected variations due to the environment.
How to create the scene and add sprites and images?
Let's create the ball scene from scratch, starting by giving it a visual representation and setting up collisions.
-
Create the scene:
- Start a new node from
Kinematic Body 2D
and name it Ball
.
-
Add image to the ball:
- Import an image in PNG format, preferably a ball, into the file system.
- Use a
Sprite
node to display it and drag the image to the Texture
property inside the sprite.
-
Set up collisions:
- Use a
Collision Shape 2D
node with a CircleShape2D
.
- Set the radius of the circle to half the size of your image (if the image measures 64x64 pixels, the radius would be 32).
How to program the motion logic?
A suitable script will control the behavior and reaction of the ball to the environment:
var speed = 0var direction = Vector2.ZEROvar isMoving = false
func _ready(): randomize() speed = 600 direction.x = [-1, 1][randi() % 2] direction.y = [-0.8, 0.8][randi() % 2] isMoving = true
func _physics_process(delta): if isMoving: var collide = move_and_collide(direction * speed * delta) if collide: direction = direction.bounce(collide.normal)
How to implement the collision system?
The move_and_collide
function handles interactions with colliding objects. In case of collision, the bounce()
method is used to reflect the direction of the ball:
- Collisions:
- Detects collisions and changes the direction using
collide.normal
.
- Collisions are reflected creating realistic bounces.
Once the code is executed, you should see the ball move and bounce correctly, interacting dynamically with the game elements. Although you may encounter some bugs, such as a "floating floor", this is part of the learning and development process in the world of game programming, so keep exploring and improving! Coming soon, we will be developing the opponent to complete the game experience - don't miss it!
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