glTF

Samples for glTF extensions

The following is a list of samples for different glTF extensions that are supported by Cesium. Each directory contains a dedicated .gltf file that contains the actual glTF asset. Additionally, each directory also contains a simple tileset.json file that is a 3D Tiles tileset which just contains the respective glTF asset as its only content. These tilesets can be viewed in CesiumJS, by hosting the base directory of this repository on a local server.

EXT_mesh_features

The EXT_mesh_features extension is a glTF 2.0 extension that allows identifying geometry or subcomponents of geometry in glTF 2.0 assets as individual 'features', by associating them with a feature ID.

The sandcastle code for viewing the EXT_mesh_features samples is shown in glTF-Mesh-Features-Samples-Sandcastle.js

Sample	Screenshot
FeatureIdAttribute Uses an attribute of a mesh primitive to assign feature IDs to vertices
FeatureIdTexture Uses a feature ID texture to assign feature IDs to texels on the surface of the geometry

EXT_structural_metadata

The EXT_structural_metadata extension is a glTF 2.0 extension that allows storing structured metadata in glTF 2.0 assets in the form of property tables. Together with the EXT_mesh_features extension, the metadata can be looked up in these tables, using the feature IDs.

The sandcastle code for viewing the EXT_structural_metadata samples is shown in glTF-Structural-Metadata-Samples-Sandcastle.js

Sample	Screenshot
FeatureIdAttributeAndPropertyTable Vertices that are associated with properties that are stored in a property table
FeatureIdTextureAndPropertyTable Texels that are associated with properties that are stored in a property table
MultipleFeatureIdsAndProperties Multiple feature ID sets that are associated with metadata containing multiple properties
SharedPropertyTable Two mesh primitives that define feature IDs, where both refer to the same property table
MultipleClasses A mesh primitive that contains two feature IDs that are used for looking up the values for two different metadata classes
ComplexTypes Features that contain properties with more complex types
SimplePropertyTexture Properties that are stored in a texture
PropertyAttributesPointCloud Properties that are stored in vertex attributes, contained in a 3D Tiles tileset that contains statistics for the metadata values.

Other glTF extensions

Sample	Screenshot
GpuInstancesMetadata An example that uses EXT_mesh_gpu_instancing to create GPU instances that are associated with feature IDs, which are used for looking up metadata in a property table
BoxPrimitiveOutline An example that uses the CESIUM_primitive_outline extension to enable outline rendering for the edges of a unit cube.