SVF2格式文件属性获取及原始单位问题的技术咨询

Great question! Let's break down your two options clearly, since you're working with SVF2 (no property.db available) and can't load the model into the Viewer:

1. Can we get a property.db for SVF2? #

Short answer: No. SVF2 uses a completely different structure than the original SVF format—there’s no standalone property.db file. Property data in SVF2 is embedded in JSON-based property chunks that are part of the derivative output, so this approach isn’t feasible for your use case.

2. Retrieving original units via the getProperties endpoint #

This is the viable path, and we can work around the unit conversion issue with a two-step API workflow:

• Step 1: Fetch the model’s original unit metadata
  Call the GET {urn}/metadata endpoint first. For Tekla-exported IFC files, you’ll find fields like lengthUnit, areaUnit, or volumeUnit in the response (e.g., "meters" for metric models). This metadata preserves the original unit assignment from the IFC’s IfcUnitAssignment entity, so you’ll know exactly what units the model was created in.

• Step 2: Convert getProperties values back to original units
  When you call GET {urn}/metadata/{guid}/properties, numeric values may be returned in imperial units (feet, inches, etc.). Use standard conversion factors based on the units you pulled from the metadata to reverse this:

  • For length: If original unit is meters, multiply feet-based values by 0.3048
  • For area: Multiply square feet values by 0.092903 to get square meters
  • For volume: Multiply cubic feet values by 0.0283168 to get cubic meters
  • For properties that include unit strings (e.g., "3.2 ft"), parse the numeric portion, apply the conversion, then reattach the original unit from the metadata.

This workflow stays entirely within REST APIs, no Viewer required, and reliably recovers the original metric units from your Tekla IFC-derived SVF2 model.

内容的提问来源于stack exchange，提问作者EsbenCN