Node Reference
Nodes are the building blocks of your LLMRT game. They form a hierarchical tree structure that defines your game's visual and interactive elements.
Base Node Properties​
All nodes share these common properties:
interface Node {
id: string // Unique identifier for the node
type: NodeType // The type of node (see types below)
transform: Transform2D // Position, scale, rotation, etc.
visible: boolean // Whether the node is rendered
children: Node[] // Child nodes
actions: Action[] // Actions to execute
triggers: Trigger[] // Event triggers
}
interface Transform2D {
position: [number, number] // [x, y] coordinates
scale: [number, number] // [scaleX, scaleY] multipliers
rotation: number // Rotation in degrees
skew: [number, number] // [skewX, skewY] in degrees
alpha: number // Opacity (0.0 to 1.0)
}
Core Node Types​
Group​
A container node that groups other nodes together. Useful for organizing and transforming multiple nodes as a unit.
{
"id": "playerGroup",
"type": "Group",
"transform": {
"position": [100, 200],
"scale": [1, 1],
"rotation": 0,
"skew": [0, 0],
"alpha": 1
},
"visible": true,
"children": [
// Child nodes here
],
"actions": [],
"triggers": []
}
Use Cases:
- Grouping related sprites (player + weapon)
- Creating composite objects
- Applying transforms to multiple nodes
- Organizing UI elements
Sprite​
Displays a 2D image or texture.
{
"id": "player",
"type": "Sprite",
"sprite": "player_idle", // Asset ID
"frame": 0, // Animation frame (optional)
"flipX": false, // Horizontal flip (optional)
"flipY": false, // Vertical flip (optional)
"tint": "#ffffff", // Color tint (optional)
"transform": {
"position": [400, 300],
"scale": [1, 1],
"rotation": 0,
"skew": [0, 0],
"alpha": 1
},
"visible": true,
"children": [],
"actions": [],
"triggers": []
}
Properties:
sprite: Asset ID of the image to displayframe: Current animation frame (for sprite sheets)flipX/flipY: Mirror the sprite horizontally/verticallytint: Color overlay (hex color)
Use Cases:
- Player characters
- Enemies and NPCs
- Background elements
- UI icons
Text​
Renders text using the theme's font settings.
{
"id": "scoreText",
"type": "Text",
"text": "Score: 0",
"fontSize": "medium", // Theme font size key
"color": "text", // Theme color key
"align": "center", // left, center, right
"baseline": "middle", // top, middle, bottom
"maxWidth": 200, // Text wrapping width (optional)
"transform": {
"position": [400, 50],
"scale": [1, 1],
"rotation": 0,
"skew": [0, 0],
"alpha": 1
},
"visible": true,
"children": [],
"actions": [],
"triggers": []
}
Properties:
text: The text content to displayfontSize: Theme font size key or pixel valuecolor: Theme color key or hex coloralign: Horizontal alignmentbaseline: Vertical alignmentmaxWidth: Maximum width before wrapping
Use Cases:
- Score displays
- Menu text
- Dialog boxes
- Instructions
Button​
An interactive text or sprite element that responds to clicks/taps.
{
"id": "startButton",
"type": "Button",
"text": "Start Game", // Text content (if text button)
"sprite": "button_bg", // Background sprite (optional)
"fontSize": "large",
"color": "text",
"hoverColor": "accent", // Color when hovered
"pressedColor": "secondary", // Color when pressed
"padding": [16, 8], // [horizontal, vertical] padding
"transform": {
"position": [400, 300],
"scale": [1, 1],
"rotation": 0,
"skew": [0, 0],
"alpha": 1
},
"visible": true,
"children": [],
"actions": [],
"triggers": [
{
"event": "on.pointer",
"button": 0,
"actions": [
{
"type": "gotoScene",
"scene": "game"
}
]
}
]
}
Properties:
text: Button text (for text buttons)sprite: Background sprite asset IDfontSize,color: Text stylinghoverColor,pressedColor: Interactive state colorspadding: Internal spacing
Use Cases:
- Menu buttons
- UI controls
- Interactive elements
Camera2D​
Defines the viewport and camera controls for 2D scenes.
{
"id": "mainCamera",
"type": "Camera2D",
"zoom": 1.0, // Zoom level
"bounds": { // Camera movement bounds (optional)
"left": -1000,
"right": 1000,
"top": -1000,
"bottom": 1000
},
"follow": "player", // Node ID to follow (optional)
"followSpeed": 0.1, // Follow interpolation speed
"shake": { // Screen shake parameters
"intensity": 0,
"duration": 0
},
"transform": {
"position": [0, 0],
"scale": [1, 1],
"rotation": 0,
"skew": [0, 0],
"alpha": 1
},
"visible": true,
"children": [],
"actions": [],
"triggers": []
}
Properties:
zoom: Camera zoom level (1.0 = normal)bounds: Movement constraintsfollow: Node ID to automatically followfollowSpeed: How quickly to follow (0-1)shake: Screen shake effect parameters
Use Cases:
- Following the player
- Cinematic camera movements
- Screen shake effects
- Zoom effects
Particles2D​
A particle system for visual effects.
{
"id": "explosion",
"type": "Particles2D",
"maxParticles": 100,
"emissionRate": 50, // Particles per second
"lifetime": 2.0, // Particle lifetime in seconds
"sprite": "particle", // Particle sprite asset
"startColor": "#ff0000",
"endColor": "#ffff00",
"startSize": 1.0,
"endSize": 0.0,
"velocity": {
"min": [-50, -100],
"max": [50, -50]
},
"acceleration": [0, 98], // Gravity
"emitting": false, // Start emitting immediately
"transform": {
"position": [400, 300],
"scale": [1, 1],
"rotation": 0,
"skew": [0, 0],
"alpha": 1
},
"visible": true,
"children": [],
"actions": [],
"triggers": []
}
Properties:
maxParticles: Maximum number of active particlesemissionRate: Particles spawned per secondlifetime: How long each particle livessprite: Particle texture asset IDstartColor/endColor: Color animationstartSize/endSize: Size animationvelocity: Initial velocity rangeacceleration: Constant acceleration (gravity)emitting: Whether actively spawning particles
Use Cases:
- Explosions
- Fire effects
- Magic spells
- Environmental effects
Module Node Types​
These nodes are available when their respective modules are included:
Mode7Plane (Mode-7 Module)​
Creates a fake-3D ground plane using Mode-7 perspective transformation.
{
"id": "ground",
"type": "Mode7Plane",
"texture": "ground_texture",
"horizon": 0.5, // Horizon line position (0-1)
"scale": 1.0, // Texture scale
"offset": [0, 0], // Texture offset
"transform": {
"position": [0, 0],
"scale": [1, 1],
"rotation": 0,
"skew": [0, 0],
"alpha": 1
},
"visible": true,
"children": [],
"actions": [],
"triggers": []
}
Use Cases:
- Racing game tracks
- Flying over terrain
- Retro 3D effects
RaycastMap (Raycast Module)​
Creates a fake-3D environment using raycasting (like Wolfenstein 3D).
{
"id": "level",
"type": "RaycastMap",
"map": [
[1, 1, 1, 1],
[1, 0, 0, 1],
[1, 0, 0, 1],
[1, 1, 1, 1]
],
"textures": ["wall1", "wall2"],
"billboards": [
{
"position": [1.5, 1.5],
"sprite": "enemy",
"scale": 1.0
}
],
"fov": 60, // Field of view in degrees
"renderDistance": 10, // Maximum render distance
"transform": {
"position": [0, 0],
"scale": [1, 1],
"rotation": 0,
"skew": [0, 0],
"alpha": 1
},
"visible": true,
"children": [],
"actions": [],
"triggers": []
}
Use Cases:
- First-person shooters
- Dungeon crawlers
- Maze games
TilemapIso (Isometric Module)​
Renders an isometric tilemap for fake-3D environments.
{
"id": "isoMap",
"type": "TilemapIso",
"tileset": "iso_tiles",
"map": [
[1, 2, 1],
[2, 3, 2],
[1, 2, 1]
],
"tileSize": [64, 32], // Tile dimensions
"elevation": [
[0, 1, 0],
[1, 2, 1],
[0, 1, 0]
],
"transform": {
"position": [400, 200],
"scale": [1, 1],
"rotation": 0,
"skew": [0, 0],
"alpha": 1
},
"visible": true,
"children": [],
"actions": [],
"triggers": []
}
Use Cases:
- Strategy games
- RPG environments
- City builders
PostChain (Post-FX Module)​
Applies post-processing effects to the rendered scene.
{
"id": "effects",
"type": "PostChain",
"effects": [
{
"type": "vignette",
"intensity": 0.5,
"color": "#000000"
},
{
"type": "bloom",
"threshold": 0.8,
"intensity": 0.3
},
{
"type": "colorGrade",
"brightness": 1.1,
"contrast": 1.2,
"saturation": 0.9
}
],
"transform": {
"position": [0, 0],
"scale": [1, 1],
"rotation": 0,
"skew": [0, 0],
"alpha": 1
},
"visible": true,
"children": [],
"actions": [],
"triggers": []
}
Use Cases:
- Atmospheric effects
- Visual polish
- Retro CRT simulation
Node Hierarchy Best Practices​
Organization​
{
"id": "root",
"type": "Group",
"children": [
{
"id": "background",
"type": "Group",
"children": [/* background elements */]
},
{
"id": "gameplay",
"type": "Group",
"children": [/* game objects */]
},
{
"id": "ui",
"type": "Group",
"children": [/* UI elements */]
},
{
"id": "effects",
"type": "Group",
"children": [/* particles, post-fx */]
}
]
}
Transform Inheritance​
- Child nodes inherit their parent's transform
- Use groups to apply transforms to multiple objects
- Position children relative to their parent
Performance Tips​
- Keep the node tree shallow when possible
- Use
visible: falseto hide nodes instead of removing them - Group static elements together
- Limit the number of active particles
Common Patterns​
Animated Sprites​
{
"id": "player",
"type": "Sprite",
"sprite": "player_walk",
"triggers": [
{
"event": "on.tick",
"actions": [
{
"type": "playSprite",
"target": "player",
"animation": "walk",
"loop": true
}
]
}
]
}
Interactive UI​
{
"id": "menu",
"type": "Group",
"children": [
{
"id": "title",
"type": "Text",
"text": "Game Menu",
"fontSize": "large"
},
{
"id": "playButton",
"type": "Button",
"text": "Play",
"triggers": [
{
"event": "on.pointer",
"actions": [{"type": "gotoScene", "scene": "game"}]
}
]
}
]
}
Following Camera​
{
"id": "camera",
"type": "Camera2D",
"follow": "player",
"followSpeed": 0.1,
"bounds": {
"left": -500,
"right": 500,
"top": -300,
"bottom": 300
}
}
This reference covers all the node types available in LLMRT. Each node type is designed to be simple yet powerful, allowing you to create complex games through composition and the action/trigger system.