How to use IFC

[lygking]

Dear people,

Please find attachments.

I have 2 question.

First, when I linked IFC model from civil3d, it isn't working well. Scale and coordinates are changed (1st page).

I couldn't find any options for unit and coordination (2nd page).

So, I made DGN file which referred original DWG model. 

And then, exported to IFC file. But it did not appear in the Revit after the link (3rd page).

Why changed scale and coordination?

Second, If the IFC model would be bound to the Revit project, it is a generic model.

But, I cannot give any parameter. And not appear in the family category (4th page).

How can I use IFC model as ordinary Revit family?

[RmsMali · Accepted solution]

Quick Info on IFC Files:

• IFC files contains data which can be read, interpreted and used in whatever ways we wish.
• Revit uses the data from ".ifc" files and create the elements as "DirectShape"  (Directshape is an object type used by Revit to store external geometry)

Understanding ".ifc" files structure:

Please note that below exercise is just to understand how ".ifc" files work

• Right click any ".ifc" file and open up in Notepad or Notepadd++ (Preferred), you can see something similar to below image.
•  You could see that each object has a name , such as "IFCPLATE" and some properties attached to it.
• Revit (or any other software) reads these data and use them in their own way to display the model or data.

Changing Categories for ".ifc" Imports:

• Accordingly, Revit has a category mapping to data from ".ifc" files. You can change them as shown below.
• You can play with the settings here and make your own  desired settings.

Adding Parameters to the DirectShape Elements.

• Adding parameters to the objects are same as applying parameters in Project.
• Under "Manage - Project Parameters", add desired parameter to the category that you have set.
• Add values as desired.

Editing Geometry and Limitations of Imported IFC Files.

• It should be understood that geometry of any imported file cannot be edited.
  
• Imported files are just blocks which you can place inside Revit. You can attach some additional parameters to them. However, these parameters are only text data which have no connection to the dimensional or other geometry properties of the imported models.
• You can add materials and assign object styles, though.

Using IFC files as Revit Family

• No inbuilt features are available (not that I know of) in Revit for importing ".ifc" files as Revit Families.
• ".ifc" files are created as Family Instances inside Project Environment.
• Alternative Approach (If you are exposed to Revit API): You can read the ".ifc" data and create the elements as "FreeFormELements" and save them as "Revit Families". This can be re-used inside your projects.

[RmsMali · Accepted solution]

Further Study into the files that you have attached:

• The reason for the dimensional value change is that, In your DWG File, the units are set as "FEET". When imported, Revit has converted these values to "MM"; thus explains the 8.5 feet shown as 2590 mm.
• Adjust the settings inside the CAD file before exporting it as ".ifc". See below video to understand further.