Tag: datums

When and how to neutralize Survey coordinates for IFC export from Revit

Luke Johnson

When exporting to IFC, you may find that Revit feeds the Survey Coordinates (or shared coordinates) to the resulting IFC file, when in fact you want it to be based on Project Coordinates.

If your project team is using origin-to-origin linking, it will be almost vital that you neutralize the Revit survey coordinates immediately prior to exporting to IFC.

This is quite easy:

  1. Make a new file based on a blank template
  2. Insert a origin locator dwg and draw a couple of model lines over the top (this is purely to give you something to “pick”)
  3. Save and close this blank RVT file (and keep it for future use)
  4. Link it into your live Revit project
  5. Use Acquire Coordinates and select the new, fresh, blank RVT file
  6. Save As this temporary RVT with neutralized survey coordinates to somewhere
  7. Now Export your IFC

Your resulting IFC file won’t be confused about which coordinate system to use – it should now Append to Navisworks and other software using the same origin-to-origin coordinate system as that in the originating Revit project.

How to Show Linked Scope Boxes and Grids in a Host Plan View by Default

Luke Johnson

The standing rule with linked datums is that if they intersect the view cutting plane, they should show up in the host. However, Matthew Nelson discovered an interesting inconsistency – for Plan Views, this doesn’t seem to apply when Scope Box has been added to Grids.

In other words, the Grids in the Linked project, when applied to a Scope Box, do not seem to show in the Host project, even if the Host plan view range intersects the Grid elements.

After some experimentation, including testing on Revit 2013, 2014 and 2015, I think I have found the solution:
If the Scope Box in the Link intersects the Level in the Link with the lowest Z value (the lowest level), then that Scope Box and any associated Datum (Grids and Reference Planes) WILL appear by default in the Host.

Got it? So this won’t work:

 But this will:

Download this to see it in action

There are 3 other ways to show linked Grids in a plan representation, even if you can’t modify the linked Scope Box as I describe above:

  • Make a Detail View with Plan Orientation that intersects the linked Scope Box
  • Copy / Monitor the Grids (which will automatically bring in the linked Scope Box too)
  • Use “By Linked View” setting in the Host

Here are those workarounds:

Copy / Monitor

Detail View

By Linked View