The KHR_materials_volume extension specifies that attenuationDistance is an optional number, with the default being infinity. But if a gltf_json::extensions::material::Volume is serialized with attenuation_distance: AttenuationDistance::default(), the output contains JSON null instead of omitting the field. This is rejected by gltf::import() and other glTF validators.
The
KHR_materials_volumeextension specifies thatattenuationDistanceis an optional number, with the default being infinity. But if agltf_json::extensions::material::Volumeis serialized withattenuation_distance: AttenuationDistance::default(), the output contains JSONnullinstead of omitting the field. This is rejected bygltf::import()and other glTF validators.