Godot Engine - Shake 3D camera script

shake_camera.gd

# usage example:
# curr_camera.shake(0.25, 40, 0.2)

extends Camera

var duration = 0.0
var period_in_ms = 0.0
var amplitude = 0.0
var timer = 0.0
var last_shook_timer = 0
var prev_x = 0.0
var prev_y = 0.0
var prev_z = 0.0
var last_offset = Vector3(0,0,0)

var original_translation = Vector3()

func _ready():
	original_translation = get_translation()

func _process(delta):
	if timer == 0:
		set_translation(original_translation)
		set_process(false)
		return
	last_shook_timer = last_shook_timer + delta
	while last_shook_timer >= period_in_ms:
		last_shook_timer = last_shook_timer - period_in_ms
		# Lerp between [amplitude] and 0.0 intensity based on remaining shake time.
		var intensity = amplitude * (1 - ((duration - timer) / duration))
		# Noise calculation logic from http://jonny.morrill.me/blog/view/14
		var new_x = rand_range(-1.0, 1.0)
		var x_offset = intensity * (prev_x + (delta * (new_x - prev_x)))
		var new_y = rand_range(-1.0, 1.0)
		var y_offset = intensity * (prev_y + (delta * (new_y - prev_y)))

		var new_z = rand_range(-1.0, 1.0)
		var z_offset = intensity * (prev_z + (delta * (new_z - prev_z)))

		prev_x = new_x
		prev_y = new_y
		prev_z = new_z
		# Track how much we've moved the offset, as opposed to other effects.
		var new_offset = Vector3(x_offset, y_offset, z_offset)
		#set_offset(get_offset() - _last_offset + new_offset)
		set_translation(get_translation() - last_offset + new_offset)
		last_offset = new_offset
	# Reset the offset when we're done shaking.
	timer = timer - delta
	if timer <= 0:
		timer = 0
		set_translation(get_translation() - last_offset)

func shake(duration, frequency, amplitude):
	# Don't interrupt current shake duration
	if(timer != 0): return

	randomize()

	self.duration = duration
	timer = duration
	period_in_ms = 1.0 / frequency
	self.amplitude = amplitude
	prev_x = rand_range(-1.0, 1.0)
	prev_y = rand_range(-1.0, 1.0)
	last_offset = Vector3(0, 0, 0)

	set_translation(original_translation)
	set_process(true)