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Akari is a realtime render engine for Hydra, focused on speed and visual fidelity at game frame rates while rendering PBR materials. Akari can be used on every platform Swift reaches: macOS, iOS, visionOS, Linux, Windows, and Android.
Akari is a Hydra Render Delegate that exists as a renderer plugin, like Storm. Where Storm is USD's reference rasterizer, Akari is a modern PBR viewport renderer meant to look good by default and to evolve toward a realtime game engine's needs.
Modern PBR render engines look the way they do because of a stack of realtime techniques over a good rasterizer:
- Rasterization. Forward+/deferred PBR, image based lighting, light probes/irradiance volumes, soft & contact shadows.
- Screen space. GTAO, SSR, screen space GI, TAA.
- Color pipeline. AgX, Filmic, etc.
- Opt-in hardware ray tracing. RT reflections, shadows, and GI via acceleration structures.
Akari is deliberately not a full path tracer like Pixar's RenderMan or Arnold. Akari is designed for speed and interactivity at game framerates, and aims to match the visual fidelity of other realtime render engines such as Blender's EEVEE and Google's Filament.
Akari builds on LabGL for its high level graphics interface API.
| Platform | Backend |
|---|---|
| macOS / iOS / visionOS | Metal |
| Linux / Android / Windows | OpenGL (now) - Vulkan (later) |
All files copyright (c) 2026 Wabi Foundation, and released under a BSD 3-Clause License. Certain files as noted are covered by their own licenses.
Akari builds on the following third-party frameworks, libraries, and fonts.
LabGL/LabFX — an immediate-mode graphics library with a classic GL 1 API surface, by Nick Porcino https://codeberg.org/meshula/LabGL License: BSD 3-Clause Credit is required if the code is distributed.
OpenUSD/Hydra — an efficient, scalable system for authoring, reading, and streaming time-sampled scene description, by Pixar Animation Studios https://github.com/PixarAnimationStudios/OpenUSD License: Tomorrow Open Source Technology License 1.0 Credit is required if the code is distributed.
Slug — GPU font rendering algorithm by Eric Lengyel Reference shaders: https://github.com/EricLengyel/Slug Paper: https://jcgt.org/published/0006/02/02/ (JCGT 2017) License: dual MIT / Apache 2.0. The patent has been dedicated to the public domain. Credit is required if the code is distributed.
AgX — filmic tone mapping algorithm, by Troy Sobotka and EaryChow's AgXBaseRec2020 matrices, used as the default view transform in Blender and adapted from Google Filament's minimal AgX implementation. Reference shaders: https://github.com/google/filament/blob/main/filament/src/ToneMapper.cpp Original AgX: https://github.com/sobotka/AgX EaryChow's AgX: https://github.com/EaryChow/AgX_LUT_Gen Blender: https://www.blender.org License: Apache 2.0 Credit is required if the code is distributed.
ACES — ACES RRT+ODT tone mapping is adapted from Filament's ACES implementation, by Google Reference shaders: https://github.com/google/filament/blob/main/filament/src/ToneMapper.cpp ACES: https://github.com/aces-aswf/aces-core License: Apache 2.0 Credit is required if the code is distributed.
Guy ACES, Hill ACES, Narkowicz ACES — additional ACES curve fits, by Tizian Zeltner https://github.com/tizian/tonemapper License: MIT
Filmic Tonemap Operators — filmic tonemapping operators, by Tizian Zeltner https://github.com/tizian/tonemapper License: MIT
Khronos PBR Neutral — neutral tone mapper, by the Khronos Group Reference shaders: https://github.com/KhronosGroup/ToneMapping/tree/main/PBR_Neutral License: Apache 2.0 Credit is required if the code is distributed.
kb_text_shape — single-header Unicode text segmentation and OpenType shaping, by Jimmy Lefevre
https://github.com/JimmyLefevre/kb (part of the kb single-header library collection)
License: zlib
FreeType — font loading and outline extraction https://freetype.org License: FreeType License (BSD-style) / GPLv2
Clay — immediate-mode UI layout library by Nic Barker https://github.com/nicbarker/clay License: zlib
RGFW — single-header cross-platform windowing by ColleagueRiley https://github.com/ColleagueRiley/RGFW License: zlib
glad2 — GL loader generator https://github.com/Dav1dde/glad License: generated code is WTFPL / CC0; loader itself is Apache 2.0
GLM — OpenGL Mathematics library https://github.com/g-truc/glm License: MIT
par_shapes — triangle mesh generation, by Philip Rideout https://github.com/prideout/par License: MIT
LabCamera — interactive camera controller, by Nick Porcino https://github.com/meshula/LabCamera License: MIT
LabText — text utilities, by Nick Porcino https://github.com/meshula/LabText License: MIT
OpenVDB — sparse volumetric data structure (used by the VoxTree demo) https://www.openvdb.org License: MPL 2.0
oneTBB — Intel Threading Building Blocks (OpenVDB dependency) https://github.com/oneapi-src/oneTBB License: Apache 2.0
Cascadia Mono — monospace programming font by Microsoft https://github.com/microsoft/cascadia-code License: SIL Open Font License 1.1
Latin Modern — TeX math serif family, derived from Computer Modern, by B. Jackowski & J.M. Nowacki / GUST https://www.gust.org.pl/projects/e-foundry/latin-modern License: GUST Font License (permissive, similar to LPPL)
STIX Two Math — mathematical OpenType font by the STIX Fonts Project https://github.com/stipub/stixfonts License: SIL Open Font License 1.1
Noto Sans Devanagari — Devanagari script font by Google https://github.com/google/fonts/tree/main/ofl/notosansdevanagari License: SIL Open Font License 1.1
Eigen https://github.com/libigl/eigen License: BSD 3-Clause
Draco https://github.com/google/draco License: Apache 2.0
ZStandard https://github.com/facebook/zstd License: BSD 3-Clause
ZLib https://www.zlib.net License: zlib
Yaml https://github.com/yaml/libyaml License: MIT
WebP https://github.com/webmproject/libwebp License: BSD 3-Clause
LZMA2 https://github.com/conor42/fast-lzma2 License: BSD 3-Clause
MiniZip https://github.com/zlib-ng/minizip-ng License: zlib
Blosc https://github.com/Blosc/c-blosc License: BSD 3-Clause
OpenVDB https://github.com/AcademySoftwareFoundation/openvdb License: Apache 2.0
OpenColorIO https://github.com/AcademySoftwareFoundation/OpenColorIO License: BSD 3-Clause
OpenImageIO https://github.com/AcademySoftwareFoundation/OpenImageIO License: BSD 3-Clause
MaterialX https://github.com/materialx/MaterialX License: Apache 2.0
LibPNG http://www.libpng.org/pub/png License: LibPNG
Boost https://github.com/boostorg/boost License: Boost Software License
Python https://python.org License: Python Software Foundation License
OpenSubdiv https://github.com/PixarAnimationStudios/OpenSubdiv License: Apache 2.0
OSL (Open Shading Language) https://github.com/AcademySoftwareFoundation/OpenShadingLanguage License: BSD 3-Clause
Ptex https://github.com/wdas/ptex License: Apache 2.0
ImGUI https://github.com/ocornut/imgui License: MIT
Embree https://github.com/RenderKit/embree License: Apache 2.0
Alembic https://github.com/alembic/alembic License: BSD 3-Clause
OpenEXR https://github.com/AcademySoftwareFoundation/openexr License: BSD 3-Clause
Imath https://github.com/AcademySoftwareFoundation/Imath License: BSD 3-Clause
HDF5 https://github.com/HDFGroup/hdf5 License: HDF5 License
TurboJPEG https://github.com/libjpeg-turbo/libjpeg-turbo License: MIT
TIFF https://github.com/libsdl-org/libtiff License: Apache 2.0