glTF-Validator

Tool to validate glTF assets.

Validation is performed against glTF 2.0 specification.

Validator writes a validation report (in JSON-format) with all found issues and asset stats.

Live drag-n-drop tool: https://github.khronos.org/glTF-Validator

NPM package: https://www.npmjs.com/package/gltf-validator

NuGet package [Third-party contribution]: https://www.nuget.org/packages/GltfValidator/

Implemented features

• JSON syntax check and GLBv2 file format correctness.
• Asset description validation
  • All properties and their types from JSON-Schemas (including implicit limitations on valid values).
  • Validity and compatibility of internal references.
  • Correctness of Data URI encoding.
• Binary buffers validation
  • Forbidden or incorrect accessor values (e.g., NaN, invalid quaternions, indecomposable matrices, etc).
  • accessor.min and accessor.max values.
  • Sparse accessors encoding.
  • Animation inputs and outputs.
• Images validation
  • Warning on non-power-of-two dimensions.
  • Warning on unsupported image features (like animations or custom color spaces).
• Extensions validation
  • EXT_texture_webp
  • KHR_animation_pointer (partial)
  • KHR_lights_punctual
  • KHR_materials_anisotropy
  • KHR_materials_clearcoat
  • KHR_materials_dispersion
  • KHR_materials_emissive_strength
  • KHR_materials_ior
  • KHR_materials_iridescence
  • KHR_materials_pbrSpecularGlossiness
  • KHR_materials_sheen
  • KHR_materials_specular
  • KHR_materials_transmission
  • KHR_materials_unlit
  • KHR_materials_variants
  • KHR_materials_volume
  • KHR_mesh_quantization
  • KHR_texture_transform
• Full list of detectable issues.

Usage

You can use hosted web front-end tool. It works completely in the browser without any server-side processing.

Command Line Tool Usage

Usage: gltf_validator [<options>] <input>

Validation report will be written to `<asset_filename>.report.json`.
If <input> is a directory, validation reports will be recursively created for each *.gltf or *.glb asset.

Validation log will be printed to stderr.

Shell return code will be non-zero if at least one error was found.
-o, --[no-]stdout                Print JSON report to stdout instead of writing it to a file. This option cannot be used with directory input.
-r, --[no-]validate-resources    Validate contents of embedded and/or referenced resources (buffers, images).
                                 (defaults to on)
-t, --[no-]write-timestamp       Write UTC timestamp to the validation report.
-p, --[no-]absolute-path         Write absolute asset path to the validation report.
-m, --[no-]messages              Print issue messages to stderr. Otherwise, only total number of issues will be printed.
-a, --[no-]all                   Print all issue messages to stderr. Otherwise, only errors will be printed. Implies --messages.
-c, --config                     YAML configuration file with validation options. See docs/config-example.yaml for details.
-h, --threads                    The number of threads for directory validation. Set to 0 (default) for auto selection.

Building

Prerequisites

1. Download and install Dart SDK for your platform.
2. Add Dart SDK bin directory to your PATH.
3. From the repository root directory, run dart pub get to get dependencies.

Fetching dependencies from behind a corporate firewall

dart pub get downloads dependencies from Google's pub.dev server over HTTPS. If you need to specify a proxy, follow these steps:

1. Set https_proxy or HTTPS_PROXY environment variable in form hostname:port.
2. If the proxy requires credentials, use this syntax: username:password@hostname:port.

dart pub get validates server's SSL certificate. If your corporate network interferes with SSL connections, follow these steps to get it running.

1. Save your corporate self-signed root certificate as X.509 file.
2. (Linux only) Try to add your cert to /etc/pki/tls/certs/ca-bundle.crt or /etc/ssl/certs.
3. If that doesn't work or if you're on Windows, add environment variable DART_VM_OPTIONS with value --root-certs-file=<cert_file>.

After doing this, dart pub get should be able to download dependencies successfully.

Clearing Caches

In rare cases, you may encounter various build issues usually caused by previously cached artifacts and/or packages. To clear all caches and re-download the dependencies, do the following steps:

1. Remove the .dart_tool directory and the pubspec.lock file from the project root directory.
2. Run dart pub cache clean --force.
3. Run dart pub get.

Drag-n-Drop Web Tool

To build the drag-n-drop online validation tool (as hosted here), follow these steps after installation:

1. Run dart run grinder web.
2. All needed files will be written to build/web directory.

To build and package the drag-n-drop online validation tool, follow these steps after installation:

1. Run dart run grinder web-archive.
2. An archive will be written to the build/gltf_validator-VERSION-web.zip file.

CLI tool

To build the CLI tool, follow these steps after installation:

1. Run dart run grinder exe.
2. Native executable file will be written to build/bin/gltf_validator (Linux and macOS) or build/bin/gltf_validator.exe (Windows).

To build and package the CLI tool, follow these steps after installation:

1. Run dart run grinder exe-archive.
2. An archive will be written to the build/gltf_validator-VERSION-PLATFORM.tar.xz (Linux and macOS) or build/gltf_validator-VERSION-PLATFORM.zip (Windows) file.

NPM Package

To build an npm package for use in Node.js environment, follow these steps after installation:

1. Run dart run grinder npm.
2. gltf-validator npm package will be written to build/node.

Refer to the npm package documentation for additional information.

Publishing

To publish an npm package, follow these steps after installation:

1. Run dart run grinder npm-publish.
2. gltf-validator npm package will be built to build/node and published to npm registry using npm publish.

Validation Issues List

To generate ISSUES.md, follow these steps after installation:

1. Run dart run grinder issues.
2. ISSUES.md file will be written to the repo root.

Contributing

Before making a pull request do the following steps:

1. Run dart format . (note the dot) to format all source files.
2. Run dart analyze to check that there are no analyzer issues.
3. Run dart test to check that the tests pass.
4. Run dart run grinder all to check that all targets build.