missing objects (IFCSPACE) in model derivative api with endpoint :urn/metadata/:guid/properties

Question

I want to access all objects contained in a model, which was translated from a IFC file. I use the API endpoint :urn/metadata/:guid/properties with optional parameter forceget set to "true". The result in json format is 17 MB in sum, so below the limit of 20 MB. The problem is, that all objects of type IFCSPACE are missing in the response. Next I used the :urn/manifest/:derivativeurn endpoint to download the properties.db SQlite database which was generated by the file translation job and I am wondering, why this database contains the missing room objects. In detail my endpoint is https://developer.api.autodesk.com/modelderivative/v2/designdata/:urn/metadata/:guid/properties?forceget=true

I saw in another post, that room information got lost from some objects. But here the problem is different as complete objects are missing in the response.

Do you have any hints?

Answer 1

Note that the sqlite database typically contains more information, also including "property flags" which may be marked as hidden. With that, it's possible that the IFCSPACE objects are marked as hidden and therefore do not appear in the JSON response.

Btw. if you request the "scene tree" (using the https://forge.autodesk.com/en/docs/model-derivative/v2/reference/http/urn-metadata-guid-GET/ endpoint), do you see the IFCSPACE objects there, or are they also missing?

Either way, if you believe that the IFCSPACE elements are not included due to an error, feel free to submit a bug report to forge (dot) help (at) autodesk (dot) com. If possible, please include a sample file that can reproduce the issue (we will not share it with anyone outside of Autodesk).

Answer 2

Are you using the legacy pipeline to translate the IFC model? The IFCSPACE elements will available when the modern IFC translation pipeline is used. i.e. either of conversionMethod: modern or switchLoader: true is set in your POST job payload.

curl --location --request POST 'https://developer.api.autodesk.com/modelderivative/v2/designdata/job' \
--header 'Authorization: Bearer ' \
--header 'x-ads-force: true' \
--header 'Content-Type: application/json' \
--data'{
   "input": {
     "urn": "{YOUR_MODEL_URN}"
   },
   "output": {
     "formats": [
       {
         "type": "svf",
         "views": [
           "3d"
         ],
         "advanced": {
            "conversionMethod": "modern"
         }
       }
     ]
   }
 }'

See field description of SVF output or SVF2 output here for references: https://forge.autodesk.com/en/docs/model-derivative/v2/reference/http/job-POST/#body-structure