Introduction to Traits

Welcome to Lesson 1.6! In this lesson, you'll learn about traits - the powerful system that adds behaviors and capabilities to your objects.

What are Traits?

Traits are HoloScript's way of adding reusable behaviors to objects. Instead of writing complex code, you simply add a trait with the @ symbol:

composition box {
  @grabbable    // Now this object can be grabbed in VR!
  geometry: "cube"
}

Core VR Traits

@grabbable

Allows users to pick up and hold the object:

composition ball {
  @grabbable
  geometry: "sphere"
  position: [0, 1.5, -1]
}

@throwable

Enables throwing with velocity based on hand movement:

composition throwingBall {
  @grabbable
  @throwable
  geometry: "sphere"

  onThrow: {
    // Called when released with velocity
  }
}

@pointable

Makes the object respond to pointing/laser pointer:

composition button {
  @pointable
  geometry: "cube"
  scale: [0.3, 0.1, 0.3]

  onPoint: {
    this.color = "#00ff00"  // Highlight when pointed at
  }
}

@hoverable

Detects when the user's hand or pointer is near:

composition hotspot {
  @hoverable
  geometry: "sphere"

  onHoverEnter: {
    this.scale = 1.2
  }

  onHoverExit: {
    this.scale = 1.0
  }
}

@clickable

Responds to click/trigger actions:

composition clickableButton {
  @clickable
  geometry: "cube"

  onClick: {
    console.log("Clicked!")
  }
}

Physics Traits

@physics

Adds realistic physics simulation:

composition fallingCube {
  @physics
  geometry: "cube"
  position: [0, 5, 0]  // Will fall due to gravity
}

With parameters:

composition heavyBall {
  @physics {
    mass: 5.0
    restitution: 0.8    // Bouncy
    friction: 0.3
  }
  geometry: "sphere"
}

@collidable

Enables collision detection:

composition wall {
  @collidable
  geometry: "cube"
  scale: [5, 3, 0.2]
}

@trigger

Creates trigger zones (no physical collision):

composition doorTrigger {
  @trigger
  geometry: "cube"
  scale: [2, 2, 1]
  opacity: 0.3

  onTriggerEnter: {
    openDoor()
  }

  onTriggerExit: {
    closeDoor()
  }
}

@gravity

Control gravity on individual objects:

composition floatingcomposition {
  @gravity { enabled: false }
  geometry: "sphere"
}

Visual Traits

@glowing

Makes the object emit light:

composition lamp {
  @glowing {
    color: "#ffffaa"
    intensity: 2.0
    distance: 10
  }
  geometry: "sphere"
  scale: 0.2
}

@animated

Auto-animates the object:

composition spinner {
  @animated {
    property: "rotation.y"
    speed: 45    // degrees per second
    loop: true
  }
  geometry: "cube"
}

@billboard

Always faces the camera:

composition label {
  @billboard
  geometry: "plane"
  material: { map: "textures/label.png" }
}

@reflective

Creates mirror-like surfaces:

composition mirror {
  @reflective
  geometry: "plane"
  scale: [2, 3, 1]
}

Networking Traits

@networked

Syncs object across multiple users:

composition sharedBall {
  @networked
  @grabbable
  geometry: "sphere"

  // Position and rotation sync automatically
}

@synced

Mark specific properties to sync:

composition scoreboard {
  @synced { properties: ["score", "playerName"] }
  score: 0
  playerName: ""
}

Combining Traits

Traits work together seamlessly:

composition interactiveBall {
  @grabbable         // Can pick it up
  @throwable         // Can throw it
  @physics {         // Realistic physics
    mass: 0.5
    restitution: 0.9
  }
  @collidable        // Collides with environment
  @networked         // Synced in multiplayer

  geometry: "sphere"
  color: "#ff6600"
  position: [0, 1.5, -1]
}

Trait Parameters

Many traits accept parameters:

// Simple trait (no parameters)
@grabbable

// Trait with parameters
@physics {
  mass: 2.0
  restitution: 0.5
}

// Short form for single parameter
@gravity false

// Alternative syntax
@animated(speed: 30)

All 1,800+ VR Traits

Here's the complete list organized by category:

Interaction (8)

@grabbable - Can be grabbed
@throwable - Can be thrown
@holdable - Must be held (like a tool)
@clickable - Responds to clicks
@hoverable - Detects hover
@draggable - Can be dragged on surfaces
@pointable - Responds to pointing
@scalable - Can be resized by user

Physics (6)

@collidable - Has collision
@physics - Full physics simulation
@rigid - Rigid body physics
@kinematic - Animated physics body
@trigger - Trigger zone
@gravity - Gravity control

Visual (6)

@glowing - Emits light
@emissive - Self-illuminated
@transparent - See-through
@reflective - Mirror surface
@animated - Auto-animation
@billboard - Faces camera

Networking (5)

@networked - Multiplayer sync
@synced - Property sync
@persistent - Saved state
@owned - Ownership control
@host_only - Host-only visibility

Behavior (5)

@stackable - Can be stacked
@attachable - Attaches to other objects
@equippable - Can be equipped
@consumable - Single-use item
@destructible - Can be destroyed

Spatial (5)

@anchor - AR world anchor
@tracked - Tracked object
@world_locked - Fixed in world space
@hand_tracked - Follows hand
@eye_tracked - Follows gaze

Audio (3)

@spatial_audio - 3D positioned sound
@ambient - Background audio
@voice_activated - Voice control

State (4)

@state - State machine
@reactive - Reactive updates
@observable - Observable pattern
@computed - Computed properties

Quiz

Test your understanding:

What trait makes an object grabbable in VR?
How do you add physics with custom mass?
What's the difference between @collidable and @trigger?
Which trait syncs an object across multiplayer?
Can you combine multiple traits on one object?

Answers

@grabbable
@physics { mass: 2.0 }
@collidable has physical collisions, @trigger only detects entry/exit
@networked
Yes, traits can be freely combined

Hands-on Exercise

Create a basketball that can be grabbed, thrown, bounces on the floor, and makes a sound on collision:

composition basketball {
  // Add your traits here

  geometry: "sphere"
  color: "#ff6600"

  // Add event handlers
}

Estimated time: 35 minutes
Difficulty: ⭐ Beginner
Next: Lesson 1.7 - Basic Interactivity

Introduction to Traits ​

What are Traits? ​

Core VR Traits ​

@grabbable ​

@throwable ​

@pointable ​

@hoverable ​

@clickable ​

Physics Traits ​

@physics ​

@collidable ​

@trigger ​

@gravity ​

Visual Traits ​

@glowing ​

@animated ​

@billboard ​

@reflective ​

Networking Traits ​

@networked ​

@synced ​

Combining Traits ​

Trait Parameters ​

All 1,800+ VR Traits ​

Interaction (8) ​

Physics (6) ​

Visual (6) ​

Networking (5) ​

Behavior (5) ​

Spatial (5) ​

Audio (3) ​

State (4) ​

Quiz ​

Hands-on Exercise ​