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Use the Category selector to determine which object you want dRofus to read from the IFC file
Press Synchronize with model
Select All Items in the filter drop-down menu and select Ok
By following these steps dRofus will import/synchronize all occurrences in the IFC file and all the systems in the IFC file. dRofus will also set system component (system owner) for the systems. For more details on how dRofus determines which occurrence to set as system component please refer to