Concepts

This section gathers the big ideas behind IWSDK — how the engine is structured and how to build XR apps that feel great and run smoothly. Jump into a topic below.

ECS (Entity–Component–System)

• Start here for the core programming model.
• How entities, components, and systems fit together; config signals; queries; lifecycle; patterns.
• Begin: /concepts/ecs

Three.js Basics for IWSDK

• Practical Three.js concepts in the context of IWSDK: transforms, scene graph, cameras, lights, geometry/materials, raycasting, and rendering performance.
• Begin: /concepts/three-basics

XR Input

• Controllers and hands with a unified model: visuals, pointers (ray/grab), XR origin spaces, and the StatefulGamepad helper.
• Begin: /concepts/xr-input
  • Highlights: Input Visuals, Pointers, Stateful Gamepad, XR Origin

Spatial UI

• High‑performance 3D UI using UIKit (Yoga‑based layout, MSDF text) with familiar authoring via UIKitML, compiled by a Vite plugin.
• Begin: /concepts/spatial-ui
  • Highlights: UIKit, UIKitML, UIKitDocument, Flow

Locomotion

• Comfort‑first movement: slide with vignette, arc‑based teleport, snap/smooth turn — all powered by a lightweight physics engine that can run in a Worker.
• Begin: /concepts/locomotion
  • Highlights: Slide, Teleport, Turn, Performance

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Suggested Path

1. ECS → 2) Three Basics → 3) XR Input → 4) Spatial UI → 5) Locomotion

You can dip into any section as needed, but this order builds intuition steadily: data model → rendering basics → input → UI → movement.