Events

An event is one sentence: when this happens, do these things.

WHEN  someone taps the door
THEN  play the creak sound
      swing it open over 600 ms
      disable the "locked" sign

The when is a trigger. The then is a list of steps. That is the whole idea — and it covers a surprising amount of what a project needs.

An object can hold as many events as you like, and each one runs independently.

These are the names you see in the editor

If you also write scripts or build patches, each one has a short code name too — the trigger and step references list both side by side. Building in the editor, you never need it.

Two generated lists to keep open

Every trigger you can react to: triggers. Every action you can take: steps. Both come straight from the engine, so they are never out of date.

Every trigger, and what it is for

The generated trigger reference has each one's parameters. This is what they mean, and where they surprise people.

Input

In the editor	Fires when
Mouse button	a tap or click — branches for click, press and release
Hover	the cursor enters or leaves the object
Double click	two clicks on the same object within 300 ms
Long press	held for 450 ms without moving
Key	a key — branches for press and release
Scroll	the wheel turns; filterable by direction
Drag	placed AR content is dragged
Pinch	placed AR content is pinched to scale
Rotate	placed AR content is twisted

The three gesture triggers only exist on surface scenes — they are about content the visitor placed. They repeat continuously while the finger moves, so treat them as a stream rather than a single moment.

Lifecycle

In the editor	Fires when
Launch	the scene starts — reaches every object
Resize	the window or viewport changes size
Pause	the app or tab goes to the background
Resume	it comes back

on-pause is where you stop things politely

Sounds keep playing when a visitor switches apps unless you stop them. Pausing audio and timers on on-pause and restoring them on on-resume is a small touch people notice.

Tracking

In the editor	Fires when
Detect	the marker or surface is found
Tracking lost	tracking is lost
Placed	the visitor placed the content
VPS ready	positioning started up
VPS localized	the visitor's real position was found
VPS localization failed	it was not — this is normal, not an error
VPS error	positioning could not run at all

Each is offered only on scenes whose anchor could produce it. Detection is reported on the edge, when tracking starts, not every frame.

A missed VPS localisation is expected

on-vps-not-localized fires routinely while the visitor walks around looking for a spot the map recognises. Treat it as "keep trying", not as a failure to announce.

Time and proximity

In the editor	Fires when
Delay	once, after a delay
Every N seconds	repeatedly — a repeat count of 0 means forever
Distance	something comes within a distance, or leaves — two branches
Visibility	the object is shown or hidden
Variable change	a variable's value changes

on-distance has a "check at start" option. Without it, an object that is already close when the scene opens will not fire until something moves.

State, physics and interface

In the editor	Fires when
State active	this object enters the state you picked
State inactive	it leaves that state
Collision	this object touches another — optionally only specific ones
UI action	a button on an interface card was pressed
Signal	another event emitted a signal
Game controls	the character changed state

One event, both directions

Some triggers have branches, so a single event handles every outcome. Set a distance once, and answer both approaching and leaving:

Trigger	Branches
Distance	entered · left
Key	pressed · released
Hover	entered · left
Mouse	click · pressed · released
Visibility	shown · hidden
Game control	idle · moving · jumping · running

You get one section per branch in the editor. Triggers without branches have a single section, "on activation".

Which objects a step affects

Every step has targets.

Leave them empty and the step acts on the object holding the event — the usual case. Fill them in and it acts on those objects instead, which is how one event on a button opens three doors.

Taps travel up to parents

A tap, a hover or a card action reaches the object and its parents.

This saves a lot of repetition: put one event on a group and it catches taps on anything inside it, instead of copying the same event onto forty objects.

Two pleasant side effects:

• "tap anywhere in this panel" is one event on the panel;
• sliding between two children of the same parent does not fire hover/blur on the parent, because you never actually left it.

Collisions are the exception — they fire only where they happened. And keyboard, scroll, resize and scene-start are not about any single object, so they reach everything.

Several keys for one event

Jump on Space or W is one event, not two copies. The first combination lives in the trigger; the rest go in an "or" list, written as text:

ArrowUp        ctrl+KeyW        KeyA+KeyS        Space+double

Modifiers belong to the combination they are written in, and an alternative replaces the binding rather than adding to it. Mouse buttons use the same format (mouse:middle).

Better still: name a project binding instead of a key. Rebind "jump" once in project settings and every event that mentions it moves with it — which is what you want the day someone asks for left-handed controls.

Every step, and what it does

Parameters are in the generated step reference.

Navigation and the outside world

In the editor	Does
Scene transition	go to another scene
Space transition	go to another space, optionally to a specific scene
Open URL	open a link, in this tab or a new one
Open messenger	Facebook, VK, OK, Instagram, Telegram, WhatsApp or Viber
Call phone number	start a phone call
Compose email	start an email
File download	download a file from your project
Contact download	offer a contact card, built from the fields you fill in

The messenger step takes a page id for Facebook, VK and OK, a username for Instagram and Telegram, and a phone number for WhatsApp and Viber.

Changing the scene

In the editor	Does
Show / hide object	show or hide the targets — on a scene this activates it
Set state	switch into a named state, optionally easing over a duration
Override properties	apply a one-off set of values as a temporary state

Animation

In the editor	Does
Play animation	play a timeline preset — loop mode, repeats, speed, delay
Stop animation	stop one
Transformation	move, rotate or scale over time
Opacity	fade
Material	blend the targets' materials toward a saved one
Bone transform	move a single bone
Built-in animation	play a clip that came with a model

Play animation can start an animation belonging to any object, not just the one holding the event — which is how one button starts a sequence involving several things at once.

Movement

In the editor	Does
Follow object	follow continuously — distance, offset, smoothing and speed
Look at object	turn to face something without moving
Stop following	stop both
Fly along path	travel along a path
Stop path flight	stop that

Logic

In the editor	Does
If — otherwise	check a condition, then run one of two nested step lists
Set variable	set, add to, or toggle a variable
Send signal	fire a signal — to the targets, or to everyone
Wait, then	pause before running the steps nested inside

Pointer

Lock pointer and Release pointer hide the mouse cursor and hand its movement to your scene — what a first-person game needs so the pointer does not wander off the window.

Conditions

if_action is a step, not a property of the event — so conditions nest, and "if inside if" is how you get more than two outcomes.

What the condition looks at is set by its source:

Source	Checks	Using
always	nothing — always true	—
variable	a variable's value	variable, operator, value
distance	how far the event's object is from another	target, operator, threshold
state	which state another object is in	target, state
visible	whether something is visible	target, flag
random	chance	threshold, as a percentage

Values are read loosely: 3 becomes a number, true becomes a boolean, anything else stays text. == and != compare exactly; the other operators compare as numbers.

Variables, signals and timers

Variables last for the visit, not for the project — they start empty each time someone opens your experience. Give them their starting values from an event on scene launch. They are the same variables a script sees as globals.

Signals (emit_signal → on-signal) chain events without copying steps: several events listen for level-complete, and anything can emit it. A signal that re-emits itself stops after eight rounds rather than freezing the frame.

Timers start when their object becomes live and reset when it is disabled. Re-enabling restarts the count instead of firing a burst of missed ticks.

States

A state is a named snapshot of an object's settings: position, colour, visibility, whatever you like. Switching to a state applies the snapshot, and switching with a duration makes it ease smoothly.

States are the tidy way to build a switch, a highlight, a door that is open or closed — without animating anything by hand.

While a state is selected, your edits go into it

Change an object while one of its states is active and you are editing that state's snapshot, not the object. This is exactly what you want when building states, and thoroughly confusing when you did not realise a state was selected.

Re-tracking

For AR scenes, each event's re-tracking mode decides what happens when the marker is lost and found again: start over immediately, never restart, or restart once the current steps have finished.

If you also write scripts

Events, patches and scripts all share one vocabulary — the same tap reaches all three.

Handle each trigger in one place only

The same trigger on the same object, wired as both an event and a script, runs twice. If something fires double, this is almost always why.

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Next: Animation — making things move.