Help! The bullet spawn position is inconsistent when I shoot while moving.

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Help! The bullet spawn position is inconsistent when I shoot while moving.

Oni

Hey guys!

As I said in the title, I'm prototyping an FPS but I'm having problems when spawning bullets while moving. It's like the bullets are getting the muzzle position from the last frame, not the current one.

I've uploaded a video to illustrate better what is happening:
Video

My code:

func shoot():
	var projectile = Projectile.instantiate() as ProjectileBase
	p.owner.add_child(projectile)
	projectile.global_transform.origin = Muzzle.global_transform.origin
	projectile.speed = 40
	projectile.direction = p.Camera.global_transform.basis.z * -1
	projectile.velocity = projectile.direction * projectile.speed

The Player and Bullet movement are being executed on _physics_process

Adding await get_tree().process_frame after add_child() and before setting the position fixes the problem but it doesn't feel like it's the best and most optimal way to approach it

Is there any other way to fix this?

JulianoBZ

Probably because its a rigid body, it may be interacting with the Player body, The following is code I use for a 2D shooter, it might be useful for you:

var b = bullet.instance()
b.position = $Bulletpoint.get_global_position()
b.rotation_degrees = rotation_degrees + tot_recoil
b.apply_impulse(Vector2(0,0),Vector2(bullet_speed,0).rotated(rotation + tot_recoil))

Instanciates the bullet, sets position in a Position2D node in front of the player, ajusts rotation and applies impulse.
Doing this might also help:

func _on_Bullet_body_entered(body):
	if not body.is_in_group("player") && !self && !self.get_parent() && !body.is_in_group("bullet"):
		queue_free()
	
	if body.is_in_group("bullet"):
		body.add_collision_exception_with(body) 
	
	if flag != body && body.is_in_group("player"):
		damage(flag,body)

verifies the group of the node and adds collision exception, in this case it asks if its another bullet, but you can ask if the body is the player who shot. The "flag" variable is the instance who shot the bullet in this code.

Again, 2D code, but I hope tou can use it