glTF Reader

The glTF Reader provides access to visualization data stored within a particular glTF file. A file does not need to have a particular extension to be read correctly by HOOPS Exchange; however, the file extensions of glTF files that you can expect to be loaded by HOOPS Exchange are:

.gltf
.glb

Physically-Based Rendering Material

As of version 2019 HOOPS Exchange now supports physically based rendering (PBR) materials with A3DGraphMaterialData structure. PBR related information are read from glTF formats.

Miscellaneous

Supported

Version 2.0 files only (tinygltf limitation; only “asset” data is correctly parsed from 1.0 files)
Vertex position, normal, color, texture coordinate sets 0 and 1
Triangles
Full texture support and material data: normal, occlusion, emissive
Physically Based Rendering (PBR) textures and constants: base color, metallness, roughness
Texture file formats: JPEG, PNG, BMP, GIF (handled by tinygltf)
Cameras

Unsupported

Version 1.0 files
Vertex tangents
Animations
Skins
Extensions
Shaders
Sparse accessors (currently not supported by tinygltf)
Byte-swapping for Big-Endian platforms

Assembly

This concept is not supported by glTF.

B-rep

This concept is not supported by glTF.

Visualization

The triangle information is parsed and provided via HOOPS Exchange.

Views

This concept is not supported by glTF.

PMI

This concept is not supported by glTF.

The detailed description of the material data format is included in the documentation of the A3DGraphMaterialData structure. For more information about accessing textures and attributes, please read the documentation for the A3DGlobalData, A3DGraphMaterialData, A3DGraphTextureApplicationData and A3DMiscAttributeData structures.

Restrictions

Compressed .glb files are currently unsupported.
Reading glTF is not available on iOS and Android.