Compendium

3D / AR / VR / XR Scene-Description DSLs Family Index

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3D / AR / VR / XR Scene-Description DSLs Family Index

type: language-family-index family: 3d-scene languages_catalogued: 33 tags: [language-reference, family-index, 3d-scene, openusd, gltf, x3d, materialx, openxr, webxr, ktx2, gaussian-splatting, openexr, openvdb, alembic, fbx, collada, obj, ply, stl, vrml]

3D / AR / VR / XR Scene-Description — Family Index

Family overview

The languages in this family describe 3D scenes, assets, materials, textures, volumetrics, and XR sessions as structured text or schema-defined binary — the class of formats meant to portably interchange a scene across engines (Unity, Unreal, Blender, Houdini, Three.js, Godot, RealityKit, Omniverse) rather than to drive a single engine internally. The 2023–2026 arc has been defined by the rise of OpenUSD as the de facto cross-vendor standard. After Pixar open-sourced USD in 2016, the Alliance for OpenUSD (AOUSD) was founded under the Linux Foundation Joint Development Foundation in August 2023 by Pixar, Adobe, Apple, Autodesk, and NVIDIA, with the explicit charter of making USD “the PDF of 3D.” The Apple/NVIDIA collaboration here is notable — these two companies are in active platform conflict almost everywhere else, but on USD they ship in lockstep. The current release line is OpenUSD 26.05 (April 24, 2026), with quarterly releases on the calendar-versioned cadence Pixar adopted in 2024.

The runtime delivery sibling is glTF 2.0 (Khronos, originally 2017), which has matured through a long wave of KHR_* material extensions — KHR_materials_anisotropy, KHR_materials_specular, KHR_materials_clearcoat, KHR_materials_sheen, KHR_materials_transmission, KHR_materials_volume, KHR_materials_iridescence, KHR_materials_dispersion — collectively positioned as “PBR Next” in 2023–2025 and now largely settled. Textures inside glTF use KTX 2.0 with Basis Universal supercompression (KHR_texture_basisu, ratified August 2020, KTX 2.0 spec Revision 4 approved February 2025). The newest entrant is KHR_gaussian_splatting, announced February 2026 and at release-candidate status, which embeds 3DGS point sets directly in glTF — the format ecosystem responding to neural-3D in real time.

The materials layer is now anchored by MaterialX (originally Industrial Light & Magic, donated to the Academy Software Foundation in July 2021, current release MaterialX 1.39.4 September 15, 2025), which has been adopted as the canonical material-definition language inside OpenUSD. Around it sits the rest of the ASWF/ILM heritage: OpenColorIO 2.4 (October 1, 2024, base for CY2025 VFX Reference Platform, headline feature ACES 2 Output Transform); OpenEXR 3.3.x (3.3.0 Sep 2024 through 3.3.8 March 2026); OpenVDB 12.0 with embedded NanoVDB for GPU volumetrics; Alembic 1.8.8 (December 2024) for cached point/mesh animation. The legacy zoo — OBJ/MTL (1990s), FBX (Autodesk, proprietary but ubiquitous), Collada DAE (Khronos, now largely retired in favour of glTF), X3D 4.0 (W3C ratified ISO/IEC December 2023, VRML’s modern successor with glTF/PBR integration), PLY, STL — all remain alive in production pipelines because real studios cannot afford to retire 30 years of asset archives.

The XR session layer is split cleanly: OpenXR 1.1 (Khronos, April 15, 2024) is the cross-platform runtime API consolidating Meta Quest, Apple Vision Pro (via OpenXR-on-visionOS), Microsoft HoloLens, ByteDance Pico, Valve Index, Sony PSVR2, HTC, Magic Leap, XREAL, Varjo, and the Monado open-source runtime; WebXR Device API (W3C, Candidate Recommendation track) is its web-platform counterpart. Apple’s Reality Composer Pro ships with Xcode and authors visionOS scenes as .usda files, cementing USD as the visionOS native format via USDZ. The emerging neural-3D wave — NeRF checkpoints and 3D Gaussian Splatting (3DGS) — entered production in 2025–2026 with PLY-as-container (Inria’s original output, often 300MB–1GB), the WebGL .splat binary format (60–70% size reduction via SH-stripping and quantisation), Niantic’s SPZ, and PlayCanvas’s KSPLAT all competing — and OpenUSD 26.03 (March 2026) added native 3DGS support, foreshadowing where the consolidation lands. This family is one of the few corners of computing where Apple and NVIDIA actively co-engineer a spec.

In our deep library

None catalogued individually. 3D-scene description languages do not have standalone deep-library notes; they sit alongside the host languages and APIs already catalogued.

Cross-reference:

  • game-engine-scripting — sibling family; covers engine-internal asset formats (Unity .prefab/.unitypackage, Unreal .uasset/Blueprint, Quake .map, Source FGD). This family covers cross-engine portable formats.
  • geospatial — sibling; covers georeferenced 3D (CityGML, OpenDRIVE, 3D Tiles, GeoPackage). 3D Tiles in particular bridges into this family because it can carry glTF tiles.
  • construction-bim — sibling; covers building-information 3D (IFC, STEP, gbXML, BCF). IFC↔USD bridges are active research.
  • gpu-and-shaders — adjacent; GLSL, HLSL, WGSL, MSL, SPIR-V, OSL. Shaders are the content materials and effects compile to; MaterialX targets all of these via shader-generation.
  • visual-dataflow — adjacent; Houdini VEX/VOPs, Blender Geometry Nodes, Grasshopper. These author the assets that USD/glTF then transport.
  • api-description — adjacent; glTF schemas are JSON-Schema-defined, and KTX2/USD have formal binary schemas.
  • notation-spec — adjacent; the USD prim/property model is a formal scene-graph grammar in the same spirit as schema-definition languages.
  • scientific — adjacent; OpenVDB and OpenEXR are heavily used in scientific visualisation and simulation pipelines.

Tier 3 family table — OpenUSD ecosystem

FormatFirst appearedOriginTypeStatus (2026)URL
OpenUSD (USDA text)2016 OSS (Pixar internal since ~2012)Pixar Animation Studios → AOUSD (Aug 2023)Composable scene-graph DSL; prim/property/layer model; LIVRPS compositionVery active, current 26.05 (Apr 24, 2026); AOUSD is the governing alliance with Pixar/Apple/NVIDIA/Adobe/Autodesk as founding membershttps://openusd.org/
USDC (crate binary)2017PixarMemory-mappable binary crate encoding of USD; fast load, smaller than USDAStandard production encodinghttps://openusd.org/release/api/usd_page_front.html
USDZ (zipped)2018Apple + PixarUncompressed zip container of USD + textures, designed for AR delivery (Quick Look, visionOS)Active, the visionOS native asset formathttps://openusd.org/release/spec_usdz.html
USD Composition Arcs (LIVRPS)2016PixarThe composition algebra inside USD: sublayers, inherits, variants, references, payloads, specializes; the actual DSL inside USDCore spec, formalised in AOUSD working groupshttps://openusd.org/release/glossary.html#livrps-strength-ordering
Hydra Render Delegate API2018PixarC++ API for plugging renderers (Storm, Karma, Arnold, RenderMan, Cycles, Omniverse RTX) into USDActive; the standard render-bridge interfacehttps://openusd.org/release/api/_page__hydra.html
Reality Composer Pro .usda2023 (visionOS preview)AppleApple’s Xcode-bundled USD authoring environment; outputs USDA scenes for RealityKit/visionOSActive, visionOS canonical authoring toolhttps://developer.apple.com/augmented-reality/tools/
Houdini USD HDA2019+ (Solaris)SideFXHoudini Digital Assets that author USD via the Solaris context (LOPs)Active, common DCC entry point to USDhttps://www.sidefx.com/products/houdini/solaris/
MX-USD (MaterialX in USD)2022+ASWF + AOUSDMaterialX node graphs embedded as USD prims; canonical material model in modern USDActive, the standard since MaterialX 1.38+https://materialx.org/
OpenUSD ProcedurallyGenerated Schema2024+ proposalAOUSD WGEmerging schema for procedurally-defined USD prims (run-time evaluation, neural assets)Emerging / draft in AOUSD working groupshttps://aousd.org/

Tier 3 family table — glTF / Khronos runtime delivery

FormatFirst appearedOriginTypeStatus (2026)URL
glTF 2.0 (JSON)2017 (2.0); 1.0 in 2015Khronos GroupJSON-schema-defined runtime 3D asset format; PBR metallic-roughness coreVery active, the runtime delivery standard for web/ARhttps://www.khronos.org/gltf/
GLB (binary container)2017KhronosSingle-file binary container wrapping glTF JSON + buffers + texturesStandard binary formhttps://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#glb-file-format-specification
KHR_materials_* (PBR Next)2020–2025Khronos 3D Formats WGMaterial extension family: anisotropy, specular, clearcoat, sheen, transmission, volume, iridescence, dispersion, emissive_strengthStable, the “PBR Next” wave is largely settled by 2026https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos
KHR_texture_basisu2020KhronosBinds KTX2 + Basis Universal textures into glTFStandard, near-universal for compressed textureshttps://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_texture_basisu/README.md
KHR_gaussian_splattingFeb 2026 (RC)KhronosEmbeds 3DGS attributes (SH coeffs, opacity, anisotropic covariance) into glTF mesh primitivesRelease candidate, full ratification expected Q2 2026https://www.khronos.org/gltf/

Tier 3 family table — Materials / textures / color / volumetrics

FormatFirst appearedOriginTypeStatus (2026)URL
MaterialX2012 (ILM internal); 1.39.4 (Sep 15, 2025)Industrial Light & Magic → ASWF (Jul 2021)XML-based material/shader graph DSL; shader-generation targets GLSL/HLSL/MSL/WGSL/OSL/MDLVery active, canonical material spec in OpenUSDhttps://materialx.org/
KTX 2.0Aug 2020 (ratified); Rev 4 Feb 2025Khronos GroupGPU-ready container with Basis Universal supercompression (ETC1S + UASTC modes)Standard, default texture format in modern glTF pipelineshttps://www.khronos.org/ktx/
Basis Universal2019Binomial LLCTranscodable supercompressed texture codec; transcodes at load to native GPU formats (BCn, ETC, ASTC, PVRTC)Standard, embedded in KTX 2.0https://github.com/BinomialLLC/basis_universal
OpenColorIO (OCIO)2010 (Sony Imageworks) → ASWFSony Pictures Imageworks → Academy Software FoundationColor-management config DSL (YAML), color-space transforms; ACES integrationVery active, current 2.4 (Oct 1, 2024); CY2025 VFX Reference Platform base; ACES 2 Output Transform previewhttps://opencolorio.org/
OpenEXR1999 (ILM)Industrial Light & Magic → ASWFHigh-dynamic-range floating-point image format; tiled, deep, multi-part imagesVery active, 3.3.8 (Mar 1, 2026); industry-standard HDR film formathttps://openexr.com/
OpenSubdiv2012Pixar Animation StudiosSubdivision-surface evaluation library + interchange; Catmull-Clark/Loop schemesStable, embedded in Maya/Houdini/Blender/USDhttps://graphics.pixar.com/opensubdiv/
OpenVDB2012 (DreamWorks) → ASWFDreamWorks Animation → Academy Software FoundationSparse hierarchical volumetric data structure + serialised formatVery active, OpenVDB 12.0 with NanoVDB GPU acceleration (CUDA/OptiX/OpenCL/OpenGL/DirectX)https://www.openvdb.org/
Alembic (.abc)2011 (1.0)Sony Pictures Imageworks + Industrial Light & MagicBaked geometric-cache format; primary use is animation interchange between DCCsActive, current 1.8.8 (Dec 2024)https://www.alembic.io/

Tier 3 family table — Legacy / interchange (OBJ/FBX/X3D/PLY/STL)

FormatFirst appearedOriginTypeStatus (2026)URL
Wavefront OBJ + MTL1990s (Wavefront Technologies)Wavefront Technologies → AutodeskASCII vertex/face/UV format with companion .mtl material fileUbiquitous legacy, still the universal lowest-common-denominatorhttp://paulbourke.net/dataformats/obj/
FBX (Filmbox)1996 (Kaydara) → Autodesk (2006)Kaydara → AutodeskProprietary binary + ASCII interchange format; rich animation, rigging, materialsActive but proprietary; ubiquitous in game/film pipelines despite open-format pressure from glTF/USDhttps://www.autodesk.com/products/fbx/overview
Collada DAE2004 (Sony) → KhronosSony Computer Entertainment → Khronos GroupXML-based interchange format; predecessor in spirit to glTFLegacy / mostly retired, superseded by glTF for runtime and USD for authoringhttps://www.khronos.org/collada/
X3D 4.0Dec 2023 (ISO/IEC ratified)Web3D ConsortiumXML/JSON/VRML-syntax 3D scene format with HTML integration, PBR, Web Audio, MIDI 2.0, HAnim2Active, ISO/IEC IS published Dec 2023; X3D 4.1 draft adds MAR (Mixed AR) capabilitieshttps://www.web3d.org/x3d4
VRML (Virtual Reality Modeling Language)1995 (1.0); 1997 (97)SGI (Mark Pesce, Tony Parisi) → Web3DText-based 3D scene description; the original Web 3DLegacy, superseded by X3D and glTF; still supported by X3D ClassicVRML encodinghttps://en.wikipedia.org/wiki/VRML
PLY (Polygon File Format)1994Stanford UniversityASCII or binary point-cloud + mesh format; minimal but extensible propertiesActive and resurgent, the de facto container for 3D Gaussian Splatting checkpoints in 2025–2026https://en.wikipedia.org/wiki/PLY_(file_format)
STL (Stereolithography)19873D Systems (Chuck Hull)ASCII/binary triangle-soup mesh; original 3D printing formatUbiquitous legacy, dominant in 3D printing, manufacturing, and CAMhttps://en.wikipedia.org/wiki/STL_(file_format)

Tier 3 family table — Web / XR / engine-specific

FormatFirst appearedOriginTypeStatus (2026)URL
WebXR Device API2018+W3C Immersive Web WGJavaScript API for AR/VR sessions in browsers; not an asset format but a session/configuration DSLActive, ongoing Candidate Recommendation work; supported in Chromium/Edge/Quest Browser, partial in Safarihttps://www.w3.org/TR/webxr/
OpenXR2019 (1.0); Apr 15, 2024 (1.1)Khronos GroupCross-platform XR runtime C API; consolidates Meta, Apple, Microsoft, ByteDance, Valve, Sony, HTC, Magic Leap, XREAL, Varjo runtimesVery active, 1.1.59 with 13 new interaction profiles consolidated; the de facto cross-vendor XR standardhttps://www.khronos.org/openxr/
A-Frame HTML DSL2015Mozilla (Diego Marcos, Kevin Ngo)HTML/JSX-style declarative VR/AR scenes; built on Three.js + WebXRActive (aframe.io), used widely for prototyping web VRhttps://aframe.io/
Three.js JSON scene2010+Ricardo Cabello (Mr.doob)JSON scene format for Three.js scenes; adjacent / engine-specificActive, library-specifichttps://threejs.org/docs/#api/en/loaders/ObjectLoader
Babylon.js scene (.babylon)2013Microsoft (David Catuhe) → communityJSON scene serialization for Babylon.js engineActive, engine-specifichttps://www.babylonjs.com/
Krpano XML2007+Klaus LeidorfXML-based panorama/360 viewer DSL; tour and hotspot scriptingActive, niche to panorama VRhttps://krpano.com/
Unreal .uasset2014 (UE4); UE5 (2022)Epic GamesProprietary engine-internal binary asset containerVery active, engine-bound — cross-listed to game-engine-scriptinghttps://docs.unrealengine.com/
Unity .unitypackage / YAML scenes2005+Unity TechnologiesUnity YAML scene/prefab + zipped package formatVery active, engine-bound — cross-listed to game-engine-scriptinghttps://unity.com/
Blender .blend1994+Ton Roosendaal → Blender FoundationProprietary self-describing binary scene file (DNA-driven schema)Very active, the default authoring format for the dominant open-source DCChttps://www.blender.org/

Tier 3 family table — Emerging (NeRF / 3DGS / volumetric)

FormatFirst appearedOriginTypeStatus (2026)URL
NeRF checkpoints2020UC Berkeley (Mildenhall et al.)Neural network weights representing a radiance field; per-implementation file formats (TensorFlow SavedModel, PyTorch .pt, INGP .ingp)Research-to-production, largely overtaken by 3DGS for real-time usehttps://www.matthewtancik.com/nerf
3D Gaussian Splatting PLY2023 (Inria SIGGRAPH paper)Inria / Université Côte d’Azur / MPIPLY container storing per-Gaussian SH coefficients, opacity, scale, rotation; 300MB–1GB typicalProduction format for training/editing 3DGS in 2025–2026https://repo-sam.inria.fr/fungraph/3d-gaussian-splatting/
3DGS .splat (raw binary)2023 (WebGL viewer ecosystem)Antimatter15 + Mark Kellogg + communityRaw binary GPU dump for rapid web ingestion; quantised + SH-stripped for 60–70% size reductionStandard for web 3DGS, until KHR_gaussian_splatting consolidateshttps://github.com/antimatter15/splat
3DGS SPZ2024Niantic (Niantic Spatial)Compact compressed 3DGS format; targets mobile/web deliveryEmerging, predicted default web 3DGS format by late 2026https://github.com/nianticlabs/spz
3DGS KSPLAT2024PlayCanvasPlayCanvas’s compressed 3DGS container; LOD-awareEmerging, engine-specifichttps://playcanvas.com/

Notable threads

  • AOUSD as the unprecedented Apple+NVIDIA alliance. The Alliance for OpenUSD, founded August 1, 2023 under the Linux Foundation’s Joint Development Foundation by Pixar, Apple, NVIDIA, Adobe, and Autodesk, is one of the very few open standards where Apple and NVIDIA — direct competitors on virtually every other technology axis — actively co-engineer the spec. Apple needs USD because visionOS uses USDZ as its native asset format and Reality Composer Pro outputs .usda; NVIDIA needs USD because Omniverse is built on it as the foundational collaboration layer. The result is that USD has corporate gravitational pull no prior open 3D format ever had. By OpenUSD 26.05 (April 24, 2026) the cadence is quarterly calendar releases (year.month) and the spec is genuinely standardised through AOUSD working groups rather than living solely as Pixar’s internal-tool-released-to-OSS.

  • glTF 2.0’s “PBR Next” extension wave has settled. Between 2020 and 2025 Khronos shipped a tightly-coupled wave of material extensions — KHR_materials_anisotropy, _specular, _clearcoat, _sheen, _transmission, _volume, _iridescence, _dispersion, _emissive_strength — that closed the visual gap between glTF and offline-renderer materials. By 2026 these are stable, broadly supported (Blender 5.1, Three.js, Babylon.js, model-viewer, Filament, Khronos Sample Viewer), and the design space has moved from “more PBR knobs” to embedding neural assets (the Feb-2026-announced KHR_gaussian_splatting) and tighter MaterialX bridges.

  • MaterialX as the canonical material layer in OpenUSD. MaterialX joined the Academy Software Foundation in July 2021 and has since been integrated into OpenUSD as the standard material spec (“MX-USD”). The current release 1.39.4 (September 15, 2025) added WebGPU Shading Language support, hex-tiled and lat-long images, NanoColor spaces, 2D fractals, and animated materials. MaterialX’s killer feature remains that the same material graph can be shader-generated to GLSL, HLSL, MSL, WGSL, OSL, and MDL — making it the closest thing the industry has to a write-once-render-everywhere material spec.

  • OpenXR’s quiet success in XR-runtime portability. Unlike historical XR fragmentation (separate SDKs for Oculus, Vive, WindowsMR, MagicLeap, Pico), OpenXR 1.1 (April 15, 2024) is now genuinely cross-platform: Meta Quest, Apple Vision Pro (via OpenXR-on-visionOS), Microsoft HoloLens, ByteDance Pico, Valve Index, Sony PSVR2, HTC, Magic Leap, XREAL, Varjo, and the open-source Monado runtime all ship conformant implementations. The 1.1 release notably consolidated 13 interaction profiles into the core spec (rather than leaving them as vendor extensions), which is the inflection point where OpenXR became “good enough” for engine vendors to drop their bespoke abstractions.

  • The FBX dominance problem. FBX is the format almost everyone hates and almost everyone uses. Originally Kaydara’s 1996 interchange format, acquired by Autodesk in 2006, it became the de facto game/film pipeline interchange despite being proprietary, version-fragmented (FBX 2014 vs 2019 vs 2020 byte layouts differ enough to break round-tripping), and licensed under terms that constrain open-source tooling. glTF and USD were both explicitly designed to displace FBX — and both partially have, but FBX persists because Maya, 3ds Max, MotionBuilder, and the Autodesk product family still treat it as native. The 2025–2026 reality is that production pipelines run USD as the source of truth + FBX as the lossy interchange when legacy demands it + glTF as the runtime delivery.

  • Reality Composer Pro and the visionOS-driven USD authoring wave. When Apple shipped Reality Composer Pro alongside Xcode for visionOS in 2023–2024, it gave USD its first mass-market authoring tool aimed at app developers rather than VFX TDs. RCP outputs .usda (text USD) scenes that load into RealityKit. Combined with Apple’s choice of USDZ as the AR Quick Look format on iOS (since 2018) and the visionOS native format, this is the channel by which USD has crossed from the film/VFX world into mainstream developer awareness. Every visionOS app ships USD assets.

  • 3D Gaussian Splatting as a real production format in 2026. The Inria 3DGS paper (SIGGRAPH 2023) moved from research curiosity to production format inside ~18 months. By 2026, the format ecosystem has stabilised around: PLY as the training/editing container (Inria’s original output, 300MB–1GB), .splat as the WebGL delivery format (60–70% smaller via SH-stripping and quantisation), SPZ (Niantic) and KSPLAT (PlayCanvas) as competing compressed mobile/web formats, and the Khronos KHR_gaussian_splatting glTF extension (announced February 2026, RC, full ratification expected Q2 2026) as the cross-vendor consolidation. OpenUSD 26.03 (March 2026) added native 3DGS support, foreshadowing where the asset pipeline lands. The interesting design tension is between neural representations (NeRF) and explicit-primitive representations (3DGS) — the latter won the production wars decisively because rasterisable Gaussian primitives slot into existing GPU pipelines, whereas NeRF requires per-frame ray-marching through an MLP.

Citations

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