Lack of Enum Support in Cesium Native

[rqassimi]

Hello,

We're encountering an issue with the lack of Enum support in Cesium Native.
We're generating tiles and we've added the property type CesiumGltf::ClassProperty::Type::ENUM using the StructuralMetadata glTF extension.
When loading the tiles in Unreal (with the Cesium Unreal Plugin) and trying to read this property using the Blueprint/C++ API, we're getting an ErrorInvalidProperty because CesiumGltf::PropertyTableView::getPropertyView in Cesium Native does not support Enums.
Could you add the support of Enums in getPropertyView?

Thanks for any help you can provide on this.

[j9liu]

Thanks for opening this issue @rqassimi ! 😄

It's true that we don't support enums in EXT_structural_metadata. I imagine we'd need to wrap them in something like a MetadataEnum class that can handle the custom mapping between arbitrary names and values.

It probably comes down to taking the scalar values of the enum, and translating them to the name of that value, right? Perhaps a function like FString MetadataEnum.GetValue(int scalar) that returns the name associated with the number. Open to other implementation ideas of course, or suggestions about expected behavior.

[rqassimi]

@j9liu Sounds good to me, but we'd probably be fine just getting the scalar value at least.

[lilleyse]

CC CesiumGS/cesium-native#728