# Hilo3D

> Hilo3D is a strict TypeScript, ESM-only graphics engine for 2D and 3D browser applications. One
> shared renderer uses a Render Graph, portable RHI and WebGPU/WebGL2 backends.

This index describes the current source documentation, which may include Unreleased features. For
the 2.0 alpha install `hilo3d@next`, resolve an exact version, and use that package's declarations.
The unqualified `latest` channel may select 1.x. Optional particle/physics addons must match the
core. DDGI currently belongs to Unreleased development; do not infer availability from package.json
alone.

Build: development; package version 2.0.0-alpha.8; source 5ae1f37d6be2405e72640bf44b966f18fc77f92b. [Build provenance](documentation/build.json).

Create Stage and Renderer asynchronously. `auto` prefers compatible WebGPU; explicit WebGPU and
WebGPU-only feature requirements fail clearly on unsupported devices. Ordinary rendering follows the
shared graph/RHI path. Portable raster uses GLSL ES 3.00; compute uses validated Direct WGSL;
readonly storage raster uses constrained GLSL ES 3.10 and the common Naga translation chain.

## Start here

- [Versions](documentation/VERSIONS.md): Release channels, installed API and development-build
  boundaries.
- [Getting started](documentation/GETTING_STARTED.md): Install, 3D scene, OrbitControls, resize
  and teardown.
- [Checked recipes](documentation/RECIPES.md): Public package examples for 2D/3D, assets, effects
  and addons.
- [Documentation index](documentation/README.md): Current contracts and task-oriented navigation.
- [API reference](https://hilo3d.js.org/docs/modules/Hilo3d.html): Hosted development API; match its
  build to your package.

## Application features

- [2D rendering](documentation/2D_RENDERING.md): Top-left camera, centered default anchors,
  sprites, text and composition.
- [Animation](documentation/ANIMATION_SYSTEM.md): Clip/layer mixing, events and time units.
- [PBR and effects](documentation/PBR_AND_POST_PROCESSING.md): Materials, linear HDR, Bloom,
  filmic and WebGPU auto exposure.
- [Particles](documentation/PARTICLE_SYSTEM.md): Optional addon, CPU/GPU/stateless plans and
  authoring contracts.
- [Physics](documentation/PHYSICS_ARCHITECTURE.md): Optional Stage Systems and independent Rapier
  2D/3D adapters.
- [Example catalog](documentation/EXAMPLE_CATALOG.md): Focused examples and backend requirements.
- [Game skill](skills/hilo3d-game/SKILL.md): Independent game scaffolding and implementation
  workflow.

## Rendering contracts

- [Architecture](documentation/RENDERING_ARCHITECTURE.md): Frame, graph/RHI, resources and
  recovery.
- [SRP](documentation/SCRIPTABLE_RENDER_PIPELINE.md): Pipeline factories, features and synchronous
  pass phases.
- [Compute and storage](documentation/COMPUTE_AND_STORAGE.md): WebGPU requirements, shaders,
  indirect work and lifetime.
- [Materials](documentation/MATERIAL_SYSTEM.md): Definition/Instance, semantic passes and GPU data
  ABI.
- [Temporal rendering](documentation/TEMPORAL_RENDERING.md): Motion, TAA/TAAU and isolated
  transparent histories.
- [GTAO](documentation/GROUND_TRUTH_AMBIENT_OCCLUSION.md): Portable ambient visibility.
- [SSR](documentation/SCREEN_SPACE_REFLECTIONS.md): WebGPU Clustered reflections and miss
  fallback.
- [SSGI](documentation/SCREEN_SPACE_GLOBAL_ILLUMINATION.md): Portable screen-space diffuse
  lighting.
- [DDGI](documentation/DYNAMIC_GLOBAL_ILLUMINATION.md): Unreleased WebGPU world-space diffuse GI
  and hybrid SSGI.
- [Volumetrics](documentation/VOLUMETRIC_LIGHTING.md): WebGPU Clustered fog and froxels.
- [Atmosphere](documentation/PHYSICAL_ATMOSPHERE_AND_WEATHER.md): LUTs, clouds, shadows and
  exposure.

## Optional

- [Contributor instructions](AGENTS.md): Rules for changing the engine repository, not consumer
  applications.
- [Engineering](documentation/ENGINEERING.md): Toolchain, testing, packaging and CI.
- [Roadmap](documentation/ROADMAP.md): Implemented slices, pending evidence and future work; not
  available API.
- [Changelog](CHANGELOG.md): Unreleased changes and published version history.