pong bouncing ball

Question

I'm trying to figure out how to make a ball bounce in Godot 4.1, but I cant find anything that works. most are for Godot 3 and some are just how to add effects to ball bouncing. I did find something in the Godot engine Q&A but I cant understand what they are saying and the code doesn't work. I have a ball scene that's a CharacterBody2D with a Sprite2D and a CollisionShape2D. this is my code:
`extends CharacterBody2D

func _ready():
set_velocity(Vector2(100, 0))

func _physics_process(delta):
var collision_info = move_and_collide(velocity * delta)
if collision_info:
velocity = velocity.bounce(collision_info.get_normal())
`

Unscientific

Answer 1

Try smaller steps. With the "print" function you can have your code print a message in the "output" tab (at the bottom of the Godot window). This is a great way to check that your program is doing what you think it's doing.

As a first step I would recommend adding a "print" inside your "if collision_info" so you can make sure the collision is detected. This should narrow down your problem.

Galilean

Answer 2

thanks! ill try it!

Unscientific

Answer 3

i noticed you didn't have a SPEED calculation in there.
A movement script should go in this order:

• Get direction

• Normalize (if needed)

• Multiply vector times speed and delta

• Then move_and_collide(velocity)
  Generally a movement calculation looks like this:

  var velocity = Vector2.ZERO()
  export var speed = 200
  
  func _ready():
         set_velocity(Vector2(100,0))
  
  func _physics_process(delta):
        var collision_info = move_and_collide(velocity * speed * delta)
        if collision_info:
              velocity = velocity.bounce(collision_info)

Seiber

Answer 4

so apparently the _ready function isn't starting. i put a print there and it didn't print anything

Unscientific

Answer 5

I tried to do that but i got errors because of the "export" before the "var speed" so i removed it and then another error because apparently you can redifine it because its used in characterBody2d.

Unscientific

Answer 6

You are using Godot 3 code in Godot 4. The export needs to be prefixed with a @. And delete the global velocity declaration (velocity is a member of CharacterBody2D now).

Timorous

Answer 7

thanks i was following SnapCraklins post. i guess he was confused

Unscientific