Visibility Notifier

Knows when the camera sees a rectangle: screen_entered / screen_exited, and can pause, disable or remove its parent off screen (enemies wake up, bullets despawn).

Type: VisibilityNotifierNode · Category: Physics & Collision · Also found as: visibility, on screen, notifier

Properties

Property	Type	Default	Description
size	vec2	(64, 64)	The rectangle (centred on the node, scaled with it) the camera has to see. Range 1 to 4096.
margin	number	0	Grows the camera’s view by this many pixels: fires a little before it really shows. Range 0 to 1024.
action	enum: None, Pause_Parent, Disable_Parent, Remove_Parent	None	What happens to the parent off screen: Pause (stops updating, resumes when seen), Disable (also stops drawing), Remove (freed once it was seen and left).
onScreen	boolean	false	The camera sees it now (runtime, read-only). Runtime state: read-only, not saved.

Plus the common properties every node has.

Lua methods

Call them on the node (self.node in its script, or self.node:get_node("path")). Every node also has the Node methods.

VisibilityNotifierNode:connect(event, handler)

Connects a handler to one of this node’s events: screen_entered (The camera started seeing it), screen_exited (The camera stopped seeing it); the tree events; custom ones.

self.node:connect("screen_entered", function(value, source) Log.info("screen_entered") end)

• event VisibilityNotifierNodeEvent|string
• handler fun(value: any, source: VisibilityNotifierNode)

Returns integer id Connection id for disconnect

VisibilityNotifierNode:get_property(path)

Reads an Inspector property by its path (vectors and colours as tables); “script.” reads a field of the node’s script.

local value = self.node:get_property("size")

• path VisibilityNotifierNodeProperty|string

Returns any

VisibilityNotifierNode:set_property(path, value, y)

Sets an Inspector property by its path: vectors as {x, y} or x, y; colours as {r, g, b[, a]} 0..1 or “#rrggbb[aa]”; enums by name; “script.” a field of the node’s script.

self.node:set_property("size", 100, 50)

• path VisibilityNotifierNodeProperty|string
• value any
• y? number

In a scene file

{
  "type": "VisibilityNotifierNode",
  "name": "VisibilityNotifier",
  "position": [
    0,
    0
  ],
  "properties": {
    "size": [
      64,
      64
    ],
    "margin": 0,
    "action": "None"
  }
}