how do i make a sprite 3d change sprites depending on which angle the camera is looking from

Help Programming
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1

Godot Version

godot 4

Question

so im new to godot and trying to make this 3d game with a 2d player character.i already know how to billboard the character but how do i change the sprite depending on the angle the camera is pointing at it?

2

Get the vector from sprite to camera by subtracting their positions. Convert it into 2d vector by eliminating the y component and get its angle using Vector2::angle(). Snap this angle to the angle step the sprite frames are rotated by using snapped(), divide that by the angle step and you’ll get the frame index.

3

maybe im just bad at coding but it’s not working for me

4

If you can share your code, you’ll get more help, as it’s too little info at the moment.

Make sure you post the code in proper formatting within triple backticks!

5

#billboarding stuff

@onready var sprite = AnimatedSprite3D
@export var camera: Camera3D

const TOTAL_DIRECTIONS = 9
const ANGLE_STEP = TAU / TOTAL_DIRECTIONS

func _process(delta):
var dir_3d = camera.global_position - global_position
var dir_2d = Vector2(dir_3d.x, dir_3d.z)

var angle = dir_2d.angle()

var snapped_angle = snapped(angle, ANGLE_STEP)

var frame = int(snapped_angle / ANGLE_STEP) % TOTAL_DIRECTIONS

if frame < 0:
	frame += TOTAL_DIRECTIONS

sprite.frame = frame

i wrote some code but i don’t think it works right

6

I could be wrong, but is TAU defined? Is this the whole script? Also the formatting is a bit off as you can see, and indents matter too. Does the editor throw you an error somewhere?

7

this is the script that just has to do with billboarding the object. i could also drop the whole script too? btw what do you mean by “is TAU defined”? and the editor throws me an error every time i run the code specifically these lines → E 0:00:01:729 _process: Invalid access to property or key ‘global_position’ on a base object of type ‘Nil’.
2d_player.gd:49 @ _process()
2d_player.gd:49 @ _process()

8

What is the script attached to? It’s telling you you’re trying to call global_position on nothing.

9

it’s attached to my character body 3d

10

Did you forget to assign camera in the inspector?

11

pretty sure i did

12

print(camera) in _process() to check its value.

13

I mean, the error informs us global_position is tried on base object nil.something is not connected correctly. Can you share some screenshots of your tree and editor perchance?

14

i think the problem here is a lack of understanding for godot so i’m gonna try and read up on the documentation to help me out here

15

I’ve done this in a shader before, it’s not super easy if you’re unfamiliar with shaders.

Technically thought the idea I use is the same in gdscript also. I use the dot product of a direction to know how aligned with a side of the character I am, and then pick the sprite based on that.