At this time the managed API does not provide direct access to element linear and volumetric properties. We will file a enhancement request to get the functionality added. Until that time, here are a couple work-arounds to consider as options.
- EC API - extract EC property values
- COM API - extract using available methods
- MDL API - extract using available (wrapped) native methods
I will update reply once the enhancement request has been filed.
[UPDATE] Enhancement 614245 has been filed to address this request
HTH,
Bob