GLTF: Next steps

Enhancement Request

#4605 is a refactored that preserve the existing behavior. This is a running list of changes or enhancements for the GLTF facilities we provide that are in addition.

Detailed Description

Changes we should implement:

• Improper use of json object in the extras (instead of an Array):

  • on the GLTF Nodes, airLoopHVACHandles, airLoopHVACMaterialNames, airLooppHVACNames are individual json object with a key that is a string representation of an integer. Instead we should make a Json Array of objects
  **See Diff**

  "extras": {
  -  "airLoopHVACHandles": {
  -    "0": "00611a5f-76dc-46bb-962e-dd46ade0a5cc",
  -    "1": "8ec55b5d-de0f-4f30-b572-7d963b121c06"
  -  },
  -  "airLoopHVACMaterialNames": {
  -    "0": "AirLoopHVAC_Air Loop HVAC 1",
  -    "1": "AirLoopHVAC_Air Loop HVAC 2"
  -  },
  -  "airLoopHVACNames": {
  -    "0": "Air Loop HVAC 1",
  -    "1": "Air Loop HVAC 2"
  -  },
  +  "airLoopHVACs": [
  +    {
  +      "Handle": "00611a5f-76dc-46bb-962e-dd46ade0a5cc",
  +      "MaterialName": "AirLoopHVAC_Air Loop HVAC 1",
  +      "Name": "Air Loop HVAC 1"
  +    },
  +    {
  +      "Handle": "8ec55b5d-de0f-4f30-b572-7d963b121c06",
  +      "MaterialName": "AirLoopHVAC_Air Loop HVAC 2",
  +      "Name": "Air Loop HVAC 2"
  +    }
  +  ],
     "airWall": false,
     "boundaryMaterialName": "",
     [.. etc..]
  }
  

  • on the GLTF Scene, modelObjectMetaData is also using a std::to_string(i) indexed object instead of an array as well
  **Example**

      "modelObjectMetaData": {
        "0": {
          "color": "#F5B3DE",
          "handle": "0154d9bd-9cd4-4702-be7d-d27ec3be041f",
          "iddObjectType": "OS:BuildingStory",
          "multiplier": 0,
          "name": "Building Story 1",
          "nominal_floorCeiling_Height": 0.0,
          "nominal_z_coordinate": 0.0,
          "open_to_below": false
        },
        "1": {
          "color": "",
          "handle": "b7954df7-87eb-4f80-87df-2896df12479c",
          "iddObjectType": "OS:Space",
          "multiplier": 0,
          "name": "Space 1",
          "nominal_floorCeiling_Height": 0.0,
          "nominal_z_coordinate": 0.0,
          "open_to_below": false
        },
  }
  

• openstudio::model::Model& is passed by const, but Rendering Colors are created and assigned to ModelObjects. While this is not terribly scary, it is incorrect. https://github.com/NREL/OpenStudio/blob/68b0787df780df813c49ba0c6cc709769b7d8771/src/gltf/GltfMaterialData.cpp#L227-L228

• Loads of .GLTF files have been commited to the resources/utilities/Geometry folder, yet we're doing nothing with them.

• The protected members toExtras() should probably return directly a tinygltf::Value or tinygltf::Node instead of a std::map<std::string, tinygltf::Value) (you then need to just wrap into a tinygltf::Value object at the point of use)

• Extras bear a bunch of xxxMaterialName (eg: buildingStoryMaterialName), yet these are not present in the tingygltf materials key

• Braces are sometimes removed from the "handle" fields (eg: buildingStoryHandle) and sometimes not (eg: the 'handle' field of the modelObjectMetaData). 1) I don't think it's necessary. 2) I think it should be consistent.

• Should maybe expose the

Enhancement requests:

• Write a GltfReverseTranslator? (is this needed/wanted?)

• Schema validation

• During the refactor in #4605, I removed some of the callback params std::function<void(double)> updatePercentage. Either put that back, or completely remove that.

Possible Implementation

Begin by reviewing the GLTF changes from #4605 and the referenced rendering-color code in src/gltf/GltfMaterialData.cpp. Inspect the GLTF resources in resources/utilities/Geometry and identify which listed enhancement can be scoped independently; completion would require an agreed subset of changes plus corresponding validation, though no specific tests are named.