I get the error "Invalid operands 'float' and 'Nil' in operator '*'." when I try to run my game

[kyolwot]

Godot v4

I want to know why I’m getting this error: Invalid operands ‘float’ and ‘Nil’ in operator ‘*’.

I’ve been following multiple tutorials on creating movement for my game, I’m new to this and don’t really understand what I could do to fix this error, my game immediately closes, and I get the error notification every time I run it. I’ve looked and looked but I can’t find anything that even helps me a little on finding a fix.

The error happens at line : velocity.x = lerp(velocity.x, direction.x * speed, delta * 1.0)

My Full Code:

extends CharacterBody3D

var speed
const WALK_SPEED = 5.0
const SPRINT_SPEED = 8.0
const CROUCH_SPEED = 3.0
const JUMP_VELOCITY = 4.8
const SENSITIVITY = 0.004

const BOB_FREQ = 2.4
const BOB_AMP = 0.08
var t_bob = 0.0

const BASE_FOV = 75.0
const FOV_CHANGE = 0.5

var gravity = 9.8
var crouching_depth = -0.5
var lerp_speed = 10.0

@onready var head = $Head
@onready var camera = $Head/Camera3D
@onready var stand_collision = $Stand_collision
@onready var crouch_collision = $Crouch_collision
@onready var ray_cast_3d = $RayCast3D

func _ready():
Input.set_mouse_mode(Input.MOUSE_MODE_CAPTURED)

func _unhandled_input(event):
if event is InputEventMouseMotion:
head.rotate_y(-event.relative.x * SENSITIVITY)
camera.rotate_x(-event.relative.y * SENSITIVITY)
camera.rotation.x = clamp(camera.rotation.x, deg_to_rad(-40), deg_to_rad(60))

func _physics_process(delta):
if not is_on_floor():
velocity.y -= gravity * delta

if Input.is_action_just_pressed("Jump") and is_on_floor():
	velocity.y = JUMP_VELOCITY

	if Input.is_action_pressed("Crouch"):
		speed = CROUCH_SPEED
		head.position.y = lerp(head.position.y, 0.444 + crouching_depth, delta * lerp_speed)
		crouch_collision.disabled = true
		stand_collision.disabled = false
	elif !ray_cast_3d.is_colliding():
		crouch_collision.disabled = false
		stand_collision.disabled = true
		
		head.position.y = lerp(head.position.y, 0.444 + crouching_depth, delta * lerp_speed)
		
		if Input.is_action_pressed("Sprint"):
			speed = SPRINT_SPEED
		else:
			speed = WALK_SPEED


var input_dir = Input.get_vector("Left", "Right", "Up", "Down")
var direction = (head.transform.basis * Vector3(input_dir.x, 0, input_dir.y)).normalized()
if is_on_floor():
	if direction:
		velocity.x = direction.x * speed
		velocity.z = direction.z * speed
	else:
		velocity.x = lerp(velocity.x, direction.x * speed, delta * 4.0)
		velocity.z = lerp(velocity.z, direction.z * speed, delta * 4.0)
else:
	velocity.x = lerp(velocity.x, direction.x * speed, delta * 1.0)
	velocity.z = lerp(velocity.z, direction.z * speed, delta * 1.0)

t_bob += delta * velocity.length() * float(is_on_floor())
camera.transform.origin = _headbob(t_bob)

var velocity_clamped = clamp(velocity.length(), 0.5, SPRINT_SPEED * 2)
var target_fov = BASE_FOV + FOV_CHANGE * velocity_clamped
camera.fov = lerp(camera.fov, target_fov, delta * 8.0)

move_and_slide()

func _headbob(time) → Vector3:
var pos = Vector3.ZERO
pos.y = sin(time * BOB_FREQ) * BOB_AMP
pos.x = cos(time * BOB_FREQ / 2) * BOB_AMP
return pos

[zdrmlpzdrmlp]

speed is null, so somehow your speed defining code before this line doesnt have any value to begin with

add a default value to speed when you declared it very early on

var speed=1.0

[kyolwot]

When I add any value to the speed variable it breaks the related speed changes (the sprint and crouch), adding a value was a fix I had already tried but it broke other things so I came here

[zdrmlpzdrmlp]

try

	var direction = (head.transform.basis * Vector3(input_dir.x, 0, input_dir.y)).normalized()
	if not speed:
		return
	if is_on_floor():

[mrcdk]

The indentation of if Input.is_action_pressed("Crouch"): ... elif !ray_cast_3d.is_colliding(): blocks is wrong, it’s inside the jump logic. Move it outside of that.

[kyolwot]

Thank you so much! That’s exactly what I needed to fix everything