How to add acceleration to character body2d

[gnarlak_bones]

Godot Version

4

Question

How do I add acceleration to the character body2d, I don't know how to code acceleration

[paintsimmon]

Acceleration is a change in velocity over time. You will need to multiply the change by delta to take time into account. So something like this:

func _physics_process(delta):
    velocity.x = move_toward(velocity.x, target_velocity, acceleration * delta)

[gnarlak_bones]

what do you mean by acceleration here and is target_vleocity just example 0, 500?

[gnarlak_bones]

Can you please get back to me with this?

[paintsimmon]

I think I already explained what acceleration is in a different question you asked.

How do I add movement impulse to a character body2d! please help!

Godot Version 4 Question How do I add movement impulse to a character body2d

[gnarlak_bones]

that was drag, you helped me with drag

[gertkeno]

It’s a similar concept. Read the docs on move_toward

You take your current velocity, and move it towards a target velocity, by an acceleration amount per second (* delta).

target_velocity is how fast (and in what direction) you want the player to move, usually this is calculated with inputs times a max speed.

var target_velocity = Input.get_axis("Left", "Right") * SPEED

acceleration is how fast you want the player to reach that max speed, in pixels per second so it may require a very large number, I recommend around eight times the max speed.

[gnarlak_bones]

can you fill this is with example numbers

func _physics_process(delta):
velocity.x = move_toward(velocity.x, target_velocity, acceleration * delta)

cause right now my brains like

func _physics_process(delta):
velocity.x = move_toward(velocity.x, 0, 500 , 1 * delta)

but that doesn’t work

[gnarlak_bones]

I get all the target_velocity now but I’m not sure about the acceleration, how do I make acceleration because I know what acceleration itself is

[gertkeno]

@gnarlak_bones

how do I make acceleration

It’s a number, like speed only higher.

const acceleration: float = 4000

[gnarlak_bones]

I know its a number, but I can’t figure out how to put it into code

[gnarlak_bones]

I kinda got it into code but its so damm weird is doesn’t feel right,

[gertkeno]

Could you paste your code? In what ways does it feel weird? Make sure to tweak the numbers

[gnarlak_bones]

var acceleration = 0

func _physics_process(delta):

if acceleration > 0:
	acceleration += -150 * delta
	velocity.x += 1000 * delta
else:
	if acceleration < 0:
		acceleration += 70 * delta
		velocity.x += -400 * delta

whenever I do a punch:
acceleration += -10

[gertkeno]

Yeah that does seem wildly different from the other code posted. Do you use move_toward anywhere in your code? Do you use Input or is this not a player controlled object?

Based only on what you pasted acceleration would have no affect on your speed or how quickly you gain speed.

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[gnarlak_bones]

When I posted that other code, I was in a rush so here is my acceleration code, it stinks so I want to make acceleration code that doesn’t stink

var acceleration = 0

func _physics_process(delta):

   if acceleration > 0:
	   acceleration += -150 * delta
	   velocity.x += 1000 * delta
   else:
   	   if acceleration < 0:
		   acceleration += 70 * delta
		   velocity.x += -1000* delta

   velocity.x = move_toward(velocity.x, 0, 300 * delta)

whenever I do a punch:
   acceleration += 10
   velocity.x += 10

this kinda works by the way ( I have move_and_slide too)
I don’t use input, it is a player controlled object but Is basically the same as input

[gertkeno]

Your pasted code does not use acceleration to calculate speed, I have no idea what unit it’s supposed to be. Your move_toward should use acceleration as a constant like in the examples provided

@paintsimmon

const acceleration: float = 4000
func _physics_process(delta):
    velocity.x = move_toward(velocity.x, target_velocity, acceleration * delta)

---

You will need to recieve input somewhere for this to be a player controlled object, make a target_velocity and define a maximum speed however you must. It seems like you are trying to use acceleration for a Input substitute, but it also interacts with punching.

[gnarlak_bones]

input as in a key being pressed to do the punch? I pretty much have that so don’t worry unless unput is something else

are you saying if I copy and pasted this code it just works acceleration and drag in together. const acceleration: float = 4000 func _physics_process(delta): velocity.x = move_toward(velocity.x, target_velocity, acceleration * delta)
Is target_velocity just how much I want the player to accelerate to? should the punch set target_velocity to something? should target_velocity be a var, is target_velocity just a number that never changes? by adding to the velocity.x does that just work with acceleration and drag now instead of only drag. how course I have copyed this code poorly so please take note that I’m referring to code you had in you last post by tomato

[gertkeno]

Input as in pressing a button yes, a function like Input.get_axis will give you a positive number for moving right, and a negative number for moving left.

@gertkeno

target_velocity is how fast (and in what direction) you want the player to move, usually this is calculated with inputs times a max speed.

var target_velocity = Input.get_axis("Left", "Right") * SPEED

@gnarlak_bones

1. Is target_velocity just how much I want the player to accelerate to?
2. should the punch set target_velocity to something?
3. should target_velocity be a var, is target_velocity just a number that never changes?

1. Yes, it will be the player’s desired speed
2. I assume not, I still do not know how you want punching to interact with speed
3. target_velocity should be a var, it will change. for example changing between a negative number to go left, a positive number to go right, and zero to stay still

[gnarlak_bones]

ok so in here move_toward(velocity.x, target_velocity, acceleration * delta)
went I make target_velocity = to a value, it just keeps moving and doesn’t slow down to start to stop. what makes the target_velocity go to 0 after it got the move_towards makes it go to the target_velocity? should I make it so when the velocity.x is equal to what I set target_velocity to than set target_velocity to 0.