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@sjvnnings
Last active April 17, 2025 20:26
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An easy to work with jump in Godot
extends KinematicBody2D
export var move_speed = 200.0
var velocity := Vector2.ZERO
export var jump_height : float
export var jump_time_to_peak : float
export var jump_time_to_descent : float
onready var jump_velocity : float = ((2.0 * jump_height) / jump_time_to_peak) * -1.0
onready var jump_gravity : float = ((-2.0 * jump_height) / (jump_time_to_peak * jump_time_to_peak)) * -1.0
onready var fall_gravity : float = ((-2.0 * jump_height) / (jump_time_to_descent * jump_time_to_descent)) * -1.0
func _physics_process(delta):
velocity.y += get_gravity() * delta
velocity.x = get_input_velocity() * move_speed
if Input.is_action_just_pressed("jump") and is_on_floor():
jump()
velocity = move_and_slide(velocity, Vector2.UP)
func get_gravity() -> float:
return jump_gravity if velocity.y < 0.0 else fall_gravity
func jump():
velocity.y = jump_velocity
func get_input_velocity() -> float:
var horizontal := 0.0
if Input.is_action_pressed("left"):
horizontal -= 1.0
if Input.is_action_pressed("right"):
horizontal += 1.0
return horizontal
@Intrivus
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Figure out I changed project settings for the ticks, if I unlock fps by turning off Vsync it still occur even when I have more FPS, I think there is a problem with the math or Godot 4

@sjvnnings
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Author

Physics framerate and rendering framerate are different in Godot. You can render the scene at a higher FPS with Vsync off, but Godot will still update the physics at a fixed interval depending on the project settings

@Intrivus
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Ik that Godot run at a fixed interval, anyways thanks for replying I will check out the RK method

@Zuhyy
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Zuhyy commented Nov 2, 2024

How would I implement this jump script into my player script with state machine in godot v4.3?

@makeryangcom
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I found an issue in version 4.4. Everything looks normal if no actual jump animation is associated. However, when the animation is added, there is always a delay, causing the player to stay in the air for a while before the animation appears.

class_name Player extends CharacterBody3D

@onready var player_collision: CollisionShape3D = $Collision
@onready var player_body: Node3D = $Body
@onready var player_skin: Node3D = $Body/Skin
@onready var player_camera: PlayerCamera = $Camera
@onready var animation_player: AnimationPlayer = $AnimationPlayer
@onready var animation_tree: AnimationTree = $AnimationTree
@onready var move_state_machine = $AnimationTree.get("parameters/MoveStateMachine/playback")

@export var player_data: Dictionary
@export var body_height: float = 1.7
@export var walk_speed: float = 4.0
@export var run_speed: float = 6.0
@export var jump_height: float = 1.6 
@export var jump_time_to_peak: float = 0.4 
@export var jump_time_to_descent: float = 0.3 
@export var jump_velocity : float = ((body_height * jump_height) / jump_time_to_peak) * -1.0
@export var jump_gravity : float = ((-(body_height) * jump_height) / (jump_time_to_peak * jump_time_to_peak)) * -1.0
@export var fall_gravity : float = ((-(body_height) * jump_height) / (jump_time_to_descent * jump_time_to_descent)) * -1.0

func _ready() -> void:
	print("[player]:_ready")

func _process(_delta: float) -> void:
	pass

func _physics_process(_delta: float) -> void:
	move_logic(_delta)
	jump_logic(_delta)
	move_and_slide()

func set_move_state(state_name: String) -> void:
	move_state_machine.travel(state_name)

func move_logic(_delta: float) -> void:
	var input_direction := Input.get_vector("left", "right", "forward", "backward").rotated(-player_camera.camera_main.global_rotation.y)
	var player_direction = Vector3(input_direction.x, 0, input_direction.y)
	var is_running: bool = Input.is_action_pressed("shift")
	var speed = run_speed if is_running else walk_speed
	if input_direction != Vector2.ZERO:
		velocity.x = player_direction.x * speed
		velocity.z = player_direction.z * speed
		var target_angle = -input_direction.angle() + PI/2
		player_skin.rotation.y = rotate_toward(player_skin.rotation.y, target_angle, 6.0 * _delta)
		set_move_state("default_men_run_loop" if is_running else "default_men_walk_loop")
	else:
		velocity.x = move_toward(velocity.x, 0, speed)
		velocity.z = move_toward(velocity.z, 0, speed)
		set_move_state("default_men_stand_idle_loop")

func jump_logic(_delta: float) -> void:
	if is_on_floor():
		if Input.is_action_just_pressed("jump"):
			velocity.y = -jump_velocity
	else:
		set_move_state("default_men_stand_jump_start")
	var gravity = jump_gravity if velocity.y > 0.0 else fall_gravity
	velocity.y -= gravity * _delta

@LiamTheMagician
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There something I just can't figure out, my implementation looks fine, but jump height seems to be disregarded completely, in Godot 4.3:

extends CharacterBody2D

@export var speed = 300.0

@export var jump_height : float = 0.5
@export var jump_time_to_peak : float = 1.0
@export var jump_time_to_descent : float = 0.5

@onready var jump_velocity : float = ((2.0 * jump_height) / jump_time_to_peak) * -1.0
@onready var jump_gravity : float = ((-2.0 * jump_height) / (jump_time_to_peak * jump_time_to_peak)) * -1.0
@onready var fall_gravity : float = ((-2.0 * jump_height) / (jump_time_to_descent * jump_time_to_peak)) * -1.0

func get_input():
	return Input.get_axis("player_left", "player_right")

func get_gravity_2D():
	return jump_gravity if velocity.y < 0.0 else fall_gravity

func jump():
	velocity.y = jump_velocity

func _physics_process(delta):
	velocity.y += get_gravity_2D() * delta
	velocity.x = get_input() * speed
	
	if Input.is_action_just_pressed("player_jump") and is_on_floor():
		jump()
	
	move_and_slide()
	

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