/aframe-webxr

name: aframe-webxr
description: Declarative web framework for building browser-based 3D, VR, and AR experiences using HTML and entity-component architecture. Use this skill when creating WebXR applications, VR experiences, AR experiences, 360-degree media viewers, or immersive web content with minimal JavaScript. Triggers on tasks involving A-Frame, WebXR, VR development, AR development, entity-component-system, declarative 3D, or HTML-based 3D scenes. Built on Three.js with accessible HTML-first approach.

A-Frame WebXR Skill

When to Use This Skill

• Build VR/AR experiences with minimal JavaScript
• Create cross-platform WebXR applications (desktop, mobile, headset)
• Prototype 3D scenes quickly with HTML primitives
• Implement VR controller interactions
• Add 3D content to web pages declaratively
• Build 360° image/video experiences
• Develop AR experiences with hit testing

Core Concepts

1. Entity-Component-System (ECS)

A-Frame uses an entity-component-system architecture where:

• **Entities** are containers (like `<div>` in HTML)
• **Components** add functionality/appearance to entities
• **Systems** provide global functionality

<!-- Entity with components -->
<a-entity
  geometry="primitive: box; width: 2"
  material="color: red; metalness: 0.5"
  position="0 1.5 -3"
  rotation="0 45 0">
</a-entity>

**Primitives** are shortcuts for common entity + component combinations:

<!-- Primitive (shorthand) -->
<a-box color="red" position="0 1.5 -3" rotation="0 45 0" width="2"></a-box>

<!-- Equivalent entity-component form -->
<a-entity
  geometry="primitive: box; width: 2"
  material="color: red"
  position="0 1.5 -3"
  rotation="0 45 0">
</a-entity>

2. Scene Setup

Every A-Frame app starts with `<a-scene>`:

<!DOCTYPE html>
<html>
  <head>
    <script src="https://aframe.io/releases/1.7.1/aframe.min.js"></script>
  </head>
  <body>
    <a-scene>
      <!-- Entities go here -->
      <a-box position="-1 0.5 -3" color="#4CC3D9"></a-box>
      <a-sphere position="0 1.25 -5" radius="1.25" color="#EF2D5E"></a-sphere>
      <a-cylinder position="1 0.75 -3" radius="0.5" height="1.5" color="#FFC65D"></a-cylinder>
      <a-plane position="0 0 -4" rotation="-90 0 0" width="4" height="4" color="#7BC8A4"></a-plane>
      <a-sky color="#ECECEC"></a-sky>
    </a-scene>
  </body>
</html>

The scene automatically injects:

• Default camera (position: `0 1.6 0`)
• Look controls (mouse drag)
• WASD controls (keyboard movement)

3. Camera Systems

**Default Camera** (auto-injected if none specified):

<a-entity camera="active: true" look-controls wasd-controls position="0 1.6 0"></a-entity>

**Custom Camera**:

<a-camera position="0 2 5" look-controls wasd-controls="acceleration: 50"></a-camera>

**Camera Rig** (for independent movement and rotation):

<a-entity id="rig" position="0 0 0">
  <!-- Camera for head tracking -->
  <a-camera look-controls></a-camera>

  <!-- Movement applied to rig, not camera -->
</a-entity>

**VR Camera Rig with Controllers**:

<a-entity id="rig" position="0 0 0">
  <!-- Camera at eye level -->
  <a-camera position="0 1.6 0"></a-camera>

  <!-- Left hand controller -->
  <a-entity
    hand-controls="hand: left"
    laser-controls="hand: left">
  </a-entity>

  <!-- Right hand controller -->
  <a-entity
    hand-controls="hand: right"
    laser-controls="hand: right">
  </a-entity>
</a-entity>

4. Lighting

**Ambient Light** (global illumination):

<a-entity light="type: ambient; color: #BBB; intensity: 0.5"></a-entity>

**Directional Light** (like sunlight):

<a-entity light="type: directional; color: #FFF; intensity: 0.8" position="1 2 1"></a-entity>

**Point Light** (radiates in all directions):

<a-entity light="type: point; color: #F00; intensity: 2; distance: 50" position="0 3 0"></a-entity>

**Spot Light** (cone-shaped beam):

<a-entity light="type: spot; angle: 45; intensity: 1.5" position="0 5 0" rotation="-90 0 0"></a-entity>

5. Materials and Textures

**Standard Material**:

<a-sphere
  material="color: #FF0000; metalness: 0.5; roughness: 0.3"
  position="0 1 -3">
</a-sphere>

**Textured Material**:

<a-assets>
  <img id="woodTexture" src="wood.jpg">
</a-assets>

<a-box material="src: #woodTexture" position="0 1 -3"></a-box>

**Flat Shading** (no lighting):

<a-plane material="shader: flat; color: #4CC3D9"></a-plane>

6. Animations

**Property Animation**:

<a-box
  position="0 1 -3"
  animation="property: rotation; to: 0 360 0; loop: true; dur: 5000">
</a-box>

**Multiple Animations** (use `animation__*` naming):

<a-sphere
  position="0 1 -3"
  animation__position="property: position; to: 0 3 -3; dir: alternate; loop: true; dur: 2000"
  animation__rotation="property: rotation; to: 360 360 0; loop: true; dur: 4000"
  animation__scale="property: scale; to: 1.5 1.5 1.5; dir: alternate; loop: true; dur: 1000">
</a-sphere>

**Event-Based Animation**:

<a-box
  color="blue"
  animation__mouseenter="property: scale; to: 1.2 1.2 1.2; startEvents: mouseenter"
  animation__mouseleave="property: scale; to: 1 1 1; startEvents: mouseleave"
  animation__click="property: rotation; from: 0 0 0; to: 0 360 0; startEvents: click">
</a-box>

7. Assets Management

Preload assets for better performance:

<a-scene>
  <a-assets>
    <!-- Images -->
    <img id="texture1" src="texture.jpg">
    <img id="skyTexture" src="sky.jpg">

    <!-- Videos -->
    <video id="video360" src="360video.mp4" autoplay loop></video>

    <!-- Audio -->
    <audio id="bgMusic" src="music.mp3" preload="auto"></audio>

    <!-- Models -->
    <a-asset-item id="tree" src="tree.gltf"></a-asset-item>

    <!-- Mixins (reusable component sets) -->
    <a-mixin id="redMaterial" material="color: red; metalness: 0.7"></a-mixin>
  </a-assets>

  <!-- Use assets