Model takeoff can be used for objects that have properties mapped in Navisworks. Quantification takes the object properties and GUID from the original publishing application, such as AutoCAD or Revit, and creates takeoff items in the workbook.
To carry out model takeoff, objects must be either a group, layer or model. If you try to takeoff a model object that is an instance, or if the object does not contain a GUID or properties, an error message is displayed.
A GUID (Globally Unique Identifier) is a 16-byte (128 bit number) that is associated with each object in a model. It is commonly split up into several fields of varying lengths and written in groups of 8-4-4-4-12 hexadecimal characters (32 characters to represent the 16 bytes or 128 bits). For example, GUIDs may look like:
When exporting files from their native application to use in Quantification, ensure the export settings include object and element property mapping.
An instance is a single object, which is referred to several times within a model, for example a tree. This has the advantage of cutting down on file size by not unnecessarily repeating an object. Quantification only supports model takeoff for objects that are at group level or above. For more about model objects, see Reference for Selection Tree Window.