Jump with Snap

In the first experiment about moving on slopes, I mentioned that with the move_and_slide_with_snap jumping would become a tricky feature. This is because since the character will stay snapped to the floor as long as the snap_vector touches the floor, it would be impossible to apply a force that would push the character upwards.

But…guess what? There is a simple workaround to handle those situations.

Download the Jump with Snap experiment:

Zeroing the snap vector

I don’t want to waste your time with fancy approaches. Neither I’ll go through the implementation of a normal jump, you can check other tutorials for that or just read the Player.gd file is quite simple.

The way you can enable the jump in KinematicBody2Ds that move with move_and_slide_with_snap is by passing a snap_vector with no length. This ensures that the snap_vector never touches the floor, thus the character won’t be snapped.

func jump():
	if is_on_floor():
		snap_vector = Vector2.ZERO
		velocity.y = -jump_strength

We first check if the character is_on_floor() because we don’t want to jump in middle air, then we set the snap_vector to Vector2.ZERO and only after that we apply the jump force using jump_strength note it’s negative because to move up we need negative values.

Turning on the snap again

Note that with only the above implementation, after the first jump the character would never snap to the floor again and would not move on slopes properly.

Remember in the move on slopes experiment that we had two constants for the SNAP_DIRECTION and the SNAP_LENGTH? Now is time to fall back to them.

Whenever we jump and touch the floor again we want to enable snapping again when the character moves, for that as soon as we touch the floor, i.e. is_on_floor() == true, we set the snap_vector back to its defaults using those constants.

func move(delta):
	velocity.y += gravity * delta
	velocity.y = move_and_slide_with_snap(velocity, snap_vector, FLOOR_NORMAL, true).y

	if is_on_floor() and snap_vector == Vector2.ZERO:
		reset_snap()

func reset_snap():
	snap_vector = SNAP_DIRECTION * SNAP_LENGTH

With that our character is ready to jump like a kangaroo!

If you have any questions or if something wasn’t clear, please leave a comment below. Don’t forget to join the community to discuss this and more topics as well. You can also make requests for more experiments you’d like me to do.

That’s it for this experiment, thank you a lot for reading. Keep developing and until the next time!