Go, Go, Godot!
  • 0

Projectiles going through collision objects

October 27, 2022

Ever had the problem where you’re firing a bullet or some kind of projectile at high speeds, and it just goes right through the collision object, instead of hitting it?

Here’s a weapon that fires a bullet at random velocities, to demonstrate the issue:

The bullets impact the character in various places, rather than at the first point of contact. I haven’t found a way to enable any kind of continuous contact option, outside of playing with the safe_margin setting. I ended up adding a raycast:

The ray cast looks somewhat like this:

func _physics_process(delta):
	ttl -= delta
	match state:
		STATES.FIRED:
			var collision: KinematicCollision2D = move_and_collide(velocity * delta)
			if collision: _on_collision(collision.get_collider(), collision.get_position())
			
			var rq = PhysicsRayQueryParameters2D.create(_last_pos, position, collision_mask)
			rq.collide_with_areas = true
			var res: Dictionary = get_world_2d().direct_space_state.intersect_ray(rq)
			if res.has("collider"):
				_on_collision(res.collider, res.position)
				position = res.position
			elif ttl <= 0:
				state = STATES.EXPIRED
		# ...

It’s definitely a hack, though. The move_and_collide should be replaced by the ray query. Using both instructions together could result in an even weirder situation; move_and_collide could skip a collision object (the issue we’re trying to fix with the ray query), but then still collide with a different collision object. Then the ray query redoes the same movement and collides with the first object that was missed by move_and_collide . Depending on the game, that could mean something like randomly shooting through shields or walls under specific circumstances.

The current approach is essentially a two-pass solution, where the first pass is sloppy, and the second pass works as intended, but doesn’t move the projectile.

Posted in Godot.
Share
PreviousMaking videos for the web with Godot 4’s Movie Writer
NextAudio Manager to handle the loading of sound effects in bulk

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Related Posts

  • Strings
    December 17, 2022

    When not all strings are Strings. Detect bugs in your GDscript more easily with static typing

    One of the benefits of working with Godot Engine is that GDScript allows one to operate high level. GDScript is dynamically typed, so not even variable types have to be specified, but I would strongly recommend using static typing wherever possible. It can help with performance but primarily adds clarity when trying to follow the …

  • February 16, 2024

    Inventory System v1.8.1 available

    A quick update to yesterday’s release with a few fixes:

  • October 9, 2023

    The Godot Jungle Demo

    It’s not Far Cry, nor Crysis, but it could be. The Realistic Jungle Demo demonstrates that Godot is capable of impressive visuals. If you want to run it yourself, download it from https://wrobot.itch.io/jungledemo. It was announced in this Reddit post. Update: The source code was released (with the commercial assets removed).

  • February 17, 2025

    Inventory System 2 Alpha 2 available

    This release contains the new Godot editor integrations. It offers an Item Library bottom panel that makes it easier to manage your inventory item types, and an inspector plugin that lets you edit items in a GGItemCollection. This also reduces the need for manually creating GGItemData resources, which simplifies item management at design time significantly. …

    © 2025 GoGoGodot.io. All rights reserved.