Making a RigidBody2D act like a homing missle

[PizzaGuy]

Godot Version

4.6.1

Question

Hey guys! I’m attempting what the title says and came up with this code":

func _process(_delta: float) -> void:
	linear_velocity = Vector2(randf_range(150, 250), 0).rotated(rotation)
	look_at(get_tree().get_first_node_in_group("player").global_position)

My RigidBody will face towards the player but won’t move. Without the look_at() line, it’ll manage to move. Not sure why. (Gravity scale is zero)

[hyvernox]

If you want full control over the velocity and rotation, consider using a CharacterBody (or even just an Area) for the missile. When using a RigidBody, you should use apply_central_force() instead of directly changing linear_velocity.

About the rotation: Its usually enough to just rotate the visual representation (the Sprite2D or whatever you are using). To constantly rotate the whole RigidBody you should use _integrate_forces():

If you only need to place a rigid body once, for example to set its initial location, you can use the methods provided by the Node3D node, such as set_global_transform() or look_at(). However, these methods cannot be called every frame or the physics engine will not be able to correctly simulate the body’s state. As an example, consider a rigid body that you want to rotate so that it points towards another object. A common mistake when implementing this kind of behavior is to use look_at() every frame, which breaks the physics simulation. Below, we’ll demonstrate how to implement this correctly.

This is from the Using RIgidBody page in the docs. The example on that page is for a RigidBody3D, but you could adjust it for a RigidBody2D.

[normalized]

Don’t. Making it act like a missile would require implementing some sort of PID controller, which is probably not something you’d want to get into.

Just use some plain 3d node and script the homing movement.

[PizzaGuy]

I realized that I shouldn’t have used a RigidBody. I was initially following the Your First 2D Game tutorial in the docs, and it uses that for some reason. Making it a CharacterBody2D solves it.