Khronos 3D Commerce glTF Certification Criteria

This article outlines the core technical standards, asset optimization rules, and validation checks required for 3D e-commerce assets to achieve official Khronos 3D Commerce certification. Passing certification ensures that glTF and GLB models display consistently, perform efficiently, and render photorealistically across diverse retail platforms, web engines, and augmented reality devices.

glTF 2.0 Validation and Schema Compliance

The baseline requirement for certification is absolute adherence to the core glTF 2.0 specification. The asset must pass the official Khronos glTF Validator with zero errors. Any warnings generated during validation must be reviewed and resolved unless explicitly permitted by the certification guidelines. The model must utilize standard .glb or .gltf formatting with correctly declared Khronos-approved extensions (such as KHR_materials_* or KHR_texture_basisu). Proprietary or vendor-specific extensions that break interoperability across standard render engines are prohibited.

Real-World Scale, Orientation, and Pivot Points

To ensure seamless integration into web viewers and AR experiences, the asset must reflect accurate real-world physical dimensions:

  • Units: Scene units must strictly represent meters (1 unit = 1 meter).
  • Orientation: Assets must follow the glTF coordinate standard: Y-axis is up, Z-axis is forward, and X-axis is right-handed.
  • Alignment: The model's origin (pivot point) must be centered horizontally (X=0, Z=0) and placed at the lowest physical boundary of the object (Y=0), ensuring the asset rests flush on ground surfaces in AR placement.

Geometry and Mesh Efficiency

Geometry must be optimized to balance visual fidelity with mobile performance and fast network delivery:

  • Topology: All geometry must consist of clean, manifold polygonal meshes, predominantly using standard triangles.
  • Polygon Budget: Models must stay within designated triangle budgets set for real-time commerce, avoiding redundant edge loops and unoptimized high-poly density.
  • Draw Calls: Meshes should be consolidated where practical to minimize draw calls without sacrificing essential functionality.
  • Transforms: Scale transformations on individual nodes must be normalized to (1, 1, 1), and rotational transforms should be baked into the geometry where possible.

PBR Material Standards and Extension Compliance

Certified models must adhere to the Physically Based Rendering (PBR) Metallic-Roughness workflow:

  • Material Model: Standard core rendering must use the pbrMetallicRoughness model.
  • Texture Channels: Metallic and roughness values must be packed correctly into a single texture map (Occlusion in Red, Roughness in Green, Metalness in Blue).
  • Advanced Extensions: If simulating complex materials, models must use approved Khronos extensions—such as KHR_materials_clearcoat, KHR_materials_transmission, KHR_materials_sheen, KHR_materials_ior, and KHR_materials_volume—rather than custom shaders.
  • Normal Mapping: Normal maps must follow standard tangent-space conventions (OpenGL format: Green channel = Y+).

Texture Optimization and Performance Budgets

Textures constitute the largest portion of a 3D file's data footprint and must meet strict performance parameters:

  • Dimensions: All textures must follow power-of-two (POT) dimensions (e.g., 512x512, 1024x1024, 2048x2048). Textures exceeding 4096x4096 are typically restricted.
  • Compression: For optimal bandwidth consumption, textures may be compressed using KTX 2.0 / Basis Universal (KHR_texture_basisu) or standard compressed formats (JPG, PNG) without noticeable compression artifacts.
  • UV Layout: UVs must be laid out efficiently within the 0 to 1 UV space, avoiding unnecessary overlaps on unique textured areas while maximizing texel density.

Cross-Renderer Visual Consistency

Beyond programmatic syntax validation, the Khronos 3D Commerce certification process evaluates visual parity. Assets are tested across multiple standard web and mobile rendering engines—such as Babylon.js, Three.js, and Google Filament—against a baseline reference render. The asset passes visual certification only when lighting response, surface roughness, transparency, and color fidelity remain visually consistent and true to the physical product across all tested target environments.