billboardifier.gd

extends VisualInstance3D

var subworld : World3D = null
var subviewport : SubViewport = null
var texture : ViewportTexture = null
var billboard : Sprite3D = null
var clone : VisualInstance3D = null
var camera : Camera3D = null
var directions = []
var angles = """
[
	[0.0, 0.447509765625, 0.0],
	[0.0, -0.447509765625, 0.0],
	[0.447509765625, 0.0, 0.0],
	[-0.447509765625, 0.0, 0.0],
	[0.0, 0.0, 0.447509765625],
	[0.0, 0.0, -0.447509765625],
	[0.3134765625, 0.3134765625, 0.0],
	[0.3134765625, -0.3134765625, 0.0],
	[-0.3134765625, 0.3134765625, 0.0],
	[-0.3134765625, -0.3134765625, 0.0],
	[0.0, 0.3134765625, 0.3134765625],
	[0.0, -0.3134765625, 0.3134765625],
	[0.3134765625, 0.0, 0.3134765625],
	[-0.3134765625, 0.0, 0.3134765625],
	[0.0, 0.3134765625, -0.3134765625],
	[0.0, -0.3134765625, -0.3134765625],
	[0.3134765625, 0.0, -0.3134765625],
	[-0.3134765625, 0.0, -0.3134765625],
	[0.140625, 0.427734375, 0.0],
	[0.427734375, 0.140625, 0.0],
	[0.140625, -0.427734375, 0.0],
	[0.427734375, -0.140625, 0.0],
	[-0.140625, 0.427734375, 0.0],
	[-0.427734375, 0.140625, 0.0],
	[-0.140625, -0.427734375, 0.0],
	[-0.427734375, -0.140625, 0.0],
	[0.0, 0.427734375, 0.140625],
	[0.0, 0.140625, 0.427734375],
	[0.1875, 0.345703125, 0.1875],
	[-0.1875, 0.345703125, 0.1875],
	[0.0, -0.427734375, 0.140625],
	[0.0, -0.140625, 0.427734375],
	[0.1875, -0.345703125, 0.1875],
	[-0.1875, -0.345703125, 0.1875],
	[0.427734375, 0.0, 0.140625],
	[0.140625, 0.0, 0.427734375],
	[0.345703125, 0.1875, 0.1875],
	[0.345703125, -0.1875, 0.1875],
	[0.1875, 0.1875, 0.345703125],
	[0.1875, -0.1875, 0.345703125],
	[-0.427734375, 0.0, 0.140625],
	[-0.140625, 0.0, 0.427734375],
	[-0.345703125, 0.1875, 0.1875],
	[-0.345703125, -0.1875, 0.1875],
	[-0.1875, 0.1875, 0.345703125],
	[-0.1875, -0.1875, 0.345703125],
	[0.0, 0.427734375, -0.140625],
	[0.0, 0.140625, -0.427734375],
	[0.1875, 0.345703125, -0.1875],
	[-0.1875, 0.345703125, -0.1875],
	[0.0, -0.427734375, -0.140625],
	[0.0, -0.140625, -0.427734375],
	[0.1875, -0.345703125, -0.1875],
	[-0.1875, -0.345703125, -0.1875],
	[0.427734375, 0.0, -0.140625],
	[0.140625, 0.0, -0.427734375],
	[0.345703125, 0.1875, -0.1875],
	[0.345703125, -0.1875, -0.1875],
	[0.1875, 0.1875, -0.345703125],
	[0.1875, -0.1875, -0.345703125],
	[-0.427734375, 0.0, -0.140625],
	[-0.140625, 0.0, -0.427734375],
	[-0.345703125, 0.1875, -0.1875],
	[-0.345703125, -0.1875, -0.1875],
	[-0.1875, 0.1875, -0.345703125],
	[-0.1875, -0.1875, -0.345703125]
]
"""

@export var observer : Node3D = null
@export var size : Vector2i = Vector2i(640, 640)
@export var distance : float = 10.0
@export_range(1, 20) var layer : int = 20

func get_descendants(node : Node):
	var descendants = []
	for child in node.get_children():
		var grandchildren = get_descendants(child)
		descendants.append(child)
		descendants += grandchildren
	return descendants

# Called when the node enters the scene tree for the first time.
func _ready():
	if (observer == null):
		return
	var json = JSON.parse_string(angles.strip_edges())
	for i in range(len(json)):
		var direction = json[i]
		if (len(direction) < 3):
			continue
		directions.append(Vector3(direction[0], direction[1], direction[2]).normalized())
	subworld = World3D.new()
	subviewport = SubViewport.new()
	subviewport.world_3d = subworld
	subviewport.size = size
	subviewport.transparent_bg = true
	#subviewport.render_target_clear_mode = SubViewport.CLEAR_MODE_ALWAYS
	#subviewport.render_target_update_mode = SubViewport.UPDATE_ALWAYS
	texture = ViewportTexture.new()
	billboard = Sprite3D.new()
	billboard.flip_h = true
	billboard.set_name(name+"_billboard")
	camera = Camera3D.new()
	camera.set_name(name+"_camera")
	for i in range(20):
		billboard.set_layer_mask_value(i+1, get_layer_mask_value(i+1))
		camera.set_cull_mask_value(i+1, false)
		set_layer_mask_value(i+1, false)
	var descendants = get_descendants(self)
	for descendant in descendants:
		if (is_instance_of(descendant, Light3D)):
			descendant.set_layer_mask_value(layer, true)
	camera.set_cull_mask_value(layer, true)
	set_layer_mask_value(layer, true)
	add_child(subviewport)
	subviewport.add_child(camera)
	clone = duplicate()
	clone.set_name(name+"_clone")
	clone.set_script(null)
	subviewport.add_child(clone)
	texture.set_viewport_path_in_scene(get_tree().root.get_path_to(subviewport))
	#await RenderingServer.frame_post_draw
	billboard.texture = subviewport.get_texture()
	billboard.transparent = true
	add_child(billboard)

# Called every frame. 'delta' is the elapsed time since the previous frame.
func _process(delta):
	#position += Vector3(randf()-0.5, 0.0, randf()-0.5)*delta*PI
	#rotate(Vector3(0.0, 1.0, 0.0), (randf()-0.5)*delta*PI*PI*PI)
	if (billboard == null):
		return
	if (observer != null):
		var index = -1
		var dot = -1.0
		var direction = (observer.position-position).normalized()
		for i in range(len(directions)):
			var temp = direction.dot(directions[i])
			if ((index < 0) || (temp > dot)):
				dot = temp
				index = i
		if (index > -1):
			direction = directions[index]
			if (direction.dot(Vector3(0.0, 1.0, 0.0)) < 0.999):
				billboard.look_at(observer.position)
				camera.position = direction*distance
				camera.look_at(Vector3())
		if (clone != null):
			var angle = deg_to_rad(rotation.y)
			index = -1
			dot = -1.0
			direction = Vector3(cos(angle), 0.0, sin(angle))
			for i in range(len(directions)):
				var temp = direction.dot(directions[i])
				if ((index < 0) || (temp > dot)):
					dot = temp
					index = i
			if (index > -1):
				direction = directions[index]
				if (direction.dot(Vector3(0.0, 1.0, 0.0)) < 0.999):
					clone.look_at(direction)