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Attention | Topic was automatically imported from the old Question2Answer platform. |
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Asked By | adamGodot |
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Old Version | Published before Godot 3 was released. |
Hello!
I am implementing a camera shake in my game. In the script i need to wait one frame. I know you could achieve it by calling yield(get_tree(),"idle_frame") but I am getting this error “First argument of yield() is null”. Here is the whole script:
extends Camera2D
var magnitude = 0
var timeLeft = 0
var is_shaking = false
func _ready():
pass
func shake(new_magnitude, lifetime):
if magnitude > new_magnitude: return
magnitude = new_magnitude
timeLeft = lifetime
if is_shaking: return
is_shaking = true
while timeLeft > 0:
var pos = Vector2()
pos.x = rand_range(-magnitude, magnitude)
pos.y = rand_range(-magnitude, magnitude)
position = pos
timeLeft -= get_process_delta_time()
yield(get_tree(),"idle_frame")
magnitude = 0
is_shaking = false
position = Vector2(0,0)
pass
The camera is attached to the World node in the main/game scene. I am calling the shake function in other scripts (like enemy script)
Thank you
get_tree() returns SceneTree only when the node is added to scene tree.
is there any chance to call shake function before it’s added to scene?
volzhs | 2018-01-29 03:09
I have this same question. I’m following the same tutorial and the function shake needs to wait 1 frame. But the line yield(get_tree(),"idle_frame") is from godot 2.14. Is there something similar for godot 3??
Thanks!
arthurZ | 2018-02-20 22:18
Is there a way to solve this First argument of yield() is null error while trying to use yield(get_tree(),"idle_frame")?
arthurZ | 2018-02-21 00:10
I think you’re calling it too soon when it’s not inside the scene tree.
Where do you call it? Probably in a setter or getter?
Check is_inside_tree().
Dlean Jeans | 2018-02-21 03:09
@arthurZ I moved your answer to comment because it’s not an answer.
volzhs | 2018-02-21 06:02