Jitter on player followed by camera

Help Programming
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1

Godot Version

4.6

Question

Why is there so much jitter visible on the player in this?

Here are some notes and what I’ve already tried:

  • physics interpolation is ON. the jitter goes away if it is off, but of course then the player and camera both move at a very visible 60hz, which doesn’t feel great.
  • changing physics jitter fix doesn’t do much.
  • both the player and camera target move in _physics_process, with the camera itself updating position by doing global_transform = camera.target.get_global_transform_interpolated() during it’s _process. I previously tried moving the camera target in _process but the result was largely the same, with neither removing jitter.
  • both the camera and camera target have Top level on, so they don’t move when the parent characterbody3d moves.
  • removing the lerped camera movement does not remove the jitter.

Scene structure

image
image253×171 6 KB

Scripts

CameraTarget

extends Marker3D

@export var OFFSET := Vector3(0, 1, 6)
@export var CAMERA_SPEED := 5
@export var LOOKAROUND_RADIUS := 2
@export var MAX_DISTANCE:= 1

@onready var player = $".."

func _physics_process(delta: float) -> void:
	var current_pos = global_position
	
	var lookaround = Input.get_vector(
		"look_left",
		"look_right",
		"look_down",
		"look_up"
		) * LOOKAROUND_RADIUS
	
	var offset = Vector3(
		OFFSET.x + lookaround.x,
		OFFSET.y + lookaround.y,
		OFFSET.z
	)
	
	var target = player.global_position + offset

	target = current_pos.lerp(target, delta * CAMERA_SPEED)
	
	global_position = target

Camera3D

extends Camera3D

@onready var camera_target: Marker3D = $"../CameraTarget"

func _process(_delta: float) -> void:
	global_transform = camera_target.get_global_transform_interpolated()

Player

extends CharacterBody3D

const MAX_SPEED := 5;
const ACCELERATION := 100;
const JUMP_VELOCITY := 4;

var current_x_velocity: float

func _physics_process(delta: float) -> void:
	var move_dir := Input.get_axis("move_left", "move_right");
	var desired_x_velocity = move_dir * MAX_SPEED;
	
	current_x_velocity = lerp(current_x_velocity, desired_x_velocity, ACCELERATION * delta)
	
	var jump_modifier = 1;
	
	# cut gravity in half if jump is held to allow higher jumps
	if not is_on_floor() && velocity.y > 0 && Input.is_action_pressed("move_jump"):
		jump_modifier = 0.5;
	
	if Input.is_action_pressed("move_jump") && is_on_floor():
		velocity.y = JUMP_VELOCITY;
	
	velocity = Vector3(current_x_velocity, velocity.y, 0);
	
	# apply gravity
	velocity += get_gravity() * delta * jump_modifier;
	
	move_and_slide();
2

If you are setting the Camera’s global position anyways you shouldn’t child it to the Player physics object. I would bet the interpolation system does a bad job with Top Level, most thing do not like Top Level nodes.

3

Gave it a go, no luck. Having the camera script run in process or physics process, and with or without the player position being fetched with get_global_transform_interpolated(), there is jitter in all combinations :frowning:

However, when lerping is disabled, a new strange issue occurs – the camera lags behind the player object at a small fixed distance when moving. Not sure if this is relevant but worth throwing in there just in case!

4

Did you try playing with Camera’s physics process priority ?