Godot 4 Bezier Plugin

An editor plugin to create and manipulate bezier cubic curves in Godot. Tested in vcersion v4.2.2.stable.mono.official.

Controls

• Shift + Left click: add point at mouse position.
• Ctrl + Left click: remove mouse under cursor.

API Reference

Variable	Type	Description
points	PackedVector2Array	Points that form the curve (curve points + control points)
flip_h	bool	When set to true, points will be flipped horizontally
flip_v	bool	When set to true, points will be flipped horizontally
force_c1	bool	If enabled, control points adjust automatically to ensure $C^1$ continuity
allow_sharp_corners	bool	If enabled, control points are not forced to stay aligned
reset	bool	When set to true, sets the curve to its initial state
draw_arrows	bool	Whether arrows should be drawn over the curve
dash_amount	int	Number of divisions on each segment. If set to 0, the curve will be filled
rotate_speed	float	Speed rotation animation
animation	bool	Whether animations should take effect
pathColor	Color	Color of the curve main path
arrowColor	Color	Color of the arrows
draw_width	float	Width of subdivisions

Method	Parameter	Returns	Description
add_point	position: Vector3	void	Add a new point to the spline at position and control points
move_point	idx: int, position: Vector2	void	Move the point at index idx to position
get_point	idx: int	void
delete_point	idx: int	bool: could delete point	Remove a curve point at index idx position and its control points
set_points	points: PackedVector2Array	void
set_points_circle	radius: float	void	Arrange the points to form a circunference of the specified radius
move_node_along_path	node: Node2D time: float on_finish_action: Callable = func() : return align_rot: bool = false	void	node will tarverse the curve in the specified time while being aligned with it if align_rot = true. When finished, on_finish_action will be called
eval	t: float	Vector2	Evaluates the spline for $t\in [0,1]$
eval_deriv	t: float	Vector2	Evaluates the spline derivative for $t\in [0,1]
cubic_bezier	p0: Vector2, p1: Vector2, p2: Vector2, p3: Vector2, t: float	Vector2	Evaluates a cubic bezier defined by p0,p1,p2,p3 for $t\in [0,1]
n_segments		int	Number of segments of cubic beziers that build the whole curve.
eval_segment	segment_idx: int,t: float	Vector2	Evaluates an individual segment for $t\in [0,1]
eval_segment_deriv	segment_idx: int, t: float	Vector2	Evaluates an individual segment dewrivative for $t\in [0,1]
cubic_bezier_deriv	p0: Vector2, p1: Vector2, p2: Vector2, p3: Vector2, t: float	Vector2	Evaluates a cubic bezier derivative defined by p0,p1,p2,p3 for $t\in [0,1]
in_curve	idx: int	bool	Check if point at idx is a curve point (not a control point)
is_control	idx: int	bool	Check if point at idx is a control point
get_opposite_control	idx: int	int: -1 if not valid point found	Given a control point index, return the index of the one that shares curve point
get_affected_curve_point	idx: int	int	Given a control point index, return the index of the curve point that it affects
make_controls_equidistant		void	Arrange pairs of control points to ensure $C^1$ continuity arrang
make_controls_aligned		void	Arrange pairs of control points to avoid sharp corners continuity
draw_segment	segment_idx: int	void	Draws an individual segment on screen
draw_arrow	t: float	void	Draws an arrow over the curve at $t\in [0,1]$ moves

Installation

1. Copy the addons folder to the root of your project.

2. Build the project.

3. Go to Project -> Project Settings -> Plugins to enable the plugin.

4. Now you can add the bezier node within Godot UI.

   

Tip

If you don't need the node to appear as a new node type, you can just add the script bezier.gd to any node.

Usage/Examples

C#

[Export] Nvode2D path;

private void ShootTNT(){
  if (Velocity.X != 0)
    path.Set("flip_h", spriteNode.FlipH);

  Vector2 spawnPos = (Vector2)path.Call("eval", 0.0f);
  Enemy target = visionCone.GetNodeInside<Enemy>();
  Vector2 targetPos = IsInstanceValid(target) ? target.GlobalPosition : GlobalPosition + RandomVector(50);
  Projectile p = tntPrefab.Instantiate<Projectile>();
  GetTree().CurrentScene.AddChild(p);
  p.GlobalPosition = GlobalPosition + spawnPos;
  p.rotateSpeed = (float)GD.RandRange(7.0, 15.0);

  Vector2 last_ctrl_point = (Vector2)path.Call("get_point", 2);
  last_ctrl_point.X = Mathf.Abs(last_ctrl_point.X) * (targetPos.X < GlobalPosition.X ? -1 : 1);
  last_ctrl_point.Y = Mathf.Abs(last_ctrl_point.Y) * (targetPos.Y < GlobalPosition.Y ? -1 : 1);

  Action stop_rotating = () => {
      p.Explode();
  };

  path.Call("move_point", 3, targetPos - GlobalPosition);
  path.Call("move_node_along_path", p, 1.0, Callable.From(stop_rotating));
}

References

• Sebastian Lague