Devices
Devices are Fusion's no-code building pieces. Put one in the world, change its settings, and it does its job: show a message, count down, react when you walk somewhere, drop props, keep score, give a quest, or tie things together with a rule.
Every Device is a short Lua script (godot/devices/<type>.lua) with settings. Nothing a Device does is out of reach of a Lua addon: press View as Lua to see exactly what runs, and copy it into your own addon to go further.
Using them¶
While playing any scenario, press F5:
- Place … puts a Device where you're looking (the first thing the crosshair hits, or 4 m ahead on the ground). A marker with its number and name shows where it is.
- Pick a placed Device to change its settings (press Enter after typing), View as Lua, or Remove it. A Device restarts with its new settings at once.
- Save Devices into the scenario writes them into the scenario's file, so they're there the next time it's played (and in the scenario when it's shared).
- A Device with an area (Trigger Zone, Quest Giver) shows it as a glowing column. In an Experience (step 4.9) only those columns show, without numbers or names; its Devices start when the player presses Start, and its maker can lock the F5 panel.
In the scenario file they are [[device]] entries; only settings that differ from the defaults are written:
[[device]]
type = "quest_giver"
at = [10.0, 0.0, 6.0]
settings = { goal = "Break a box", kind = "prop.box", count = 1 }The Devices¶
| Device | Does | Settings (defaults) |
|---|---|---|
| Message | shows a message when the scenario starts, or when a signal arrives | text "Welcome!", seconds 5, delay 1, on_signal "" |
| Timer | counts down on the screen; at zero shows a message and sends a signal | seconds 60, label "Time left", done_text, signal "timer_done", start_on "" |
| Trigger Zone | when the player walks into it, shows a message and sends a signal | radius 3, text, signal "zone_entered", once true |
| Spawner | drops physics props, one every few seconds, up to a count | shape "box", color "orange", count 5, every 2, start_on "" |
| Scoreboard | counts entities that die (any game's, or one kind) | title "Score", kind "", points 1 |
| Quest Giver | when the player comes close, gives a quest to defeat some entities; says when it's done and sends a signal | radius 3, goal, kind "", count 3, done_text, signal "quest_done" |
| Rule | when something happens (a signal, the player near, an entity dying), do something (a message, a signal, call entities here, put a game to sleep or wake it) | when "signal", when_value "quest_done", radius 3, action "message", action_value "Well done!", once true |
Signals tie Devices together: a Trigger Zone's signal can start a Timer (start_on), a Quest Giver's signal can fire a Rule, and so on. Lua addons can send and hear them too (Fusion.signal(name), the Fusion.Signal hook).
Making a Device¶
A Device template is a Lua file in godot/devices/. Its first lines describe it:
--- device: Message
--- about: Shows a message on the screen when the scenario starts.
--- setting: text = "Welcome!"
--- setting: seconds = 5--- device:its name (required, first line);--- about:one sentence for the panel;--- area: radius(optional): the number setting that is the radius of the area it works in; Fusion draws that area as a glowing column;--- setting: key = value: a setting and its default. Values are written like TOML: text in quotes, numbers,true/false.
When a Device is placed, Fusion puts one line in front of the template:
local Device = { id = "device_1", type = "message", pos = Vector(0, 0, 6), settings = { text = "Welcome!", seconds = 5 } }So the script reads Device.settings.text, Device.pos, and uses Device.id as its hook name. Everything else is the normal Lua API (docs/lua-api.md), with the same sandbox and limits. Each placed Device runs as an addon of its own: if one breaks, the others keep going, and its error shows in the addon log.