Where is the ceiling?!!? Check the Underlay Orientation

Fewer things in life are more frustrating then when you think you have all the bases covered, and yet you’ve overlooked the obvious.

Here’s a real-life example:  A friend of mine owned a lawn mower that would not start.  So after doing a little research online (as he was not a small engine mechanic by trade), he performed some basic maintenance:  cleaned fuel filter, carburetor and belts, checked the spark plug, and changed the oil.  Satisfied that he did everything by the book, he put the mower back together and gave the pull-cord a yank.  No dice.  He tried again.  Nothing.  Getting frustrated, he started the tried-and-true method of kicking the mower.   Still wouldn’t start.  Finally, after calling the (inanimate) mower a slew of bad names and threatening the (lifeless) mower with certain harm and even permanent injury, I….umm..I mean, my friend thought, ‘Hmmm.  I wonder if there’s enough gasoline in the tank’.

We all know how this story ends.  Gas was added and mower started on the second try.  Despite being so thorough, the obvious item (gas) was overlooked.  My buddy felt kinda silly, but you can bet that will be one of the first things he’ll check next time.

The same principle applies to resolving issues in Revit.  Sometimes, it’s the seemingly obvious things that we forget to check.  One specific issue that has come up several times from Revit MEP users is the inability to see the ceiling grid in their ceiling plan views, particularly when the ceiling is on a linked model.  In most of these cases, customers have done their due diligence and checked all the right things:

• Ceiling category is on in Visibility/Graphics
• Worksets are visible
• The view range settings are correct
• The view discipline is set properly
• The correct view template has been applied
• The linked model actually has a ceiling grid

Yet, after verifying all of this, the ceiling still does not appear.  Frustrating.  But, what is the one thing that these individuals often overlook?  It is the Underlay Orientation setting in the view properties.

In Revit MEP, Underlay Orientation can be set to either Plan or Reflected Ceiling Plan.  By default, this parameter is set to Plan when creating new reflected ceiling plan views.  As long as it is set to Plan, the ceiling grid will not be visible.  Seems so obvious, right?  Well, not necessarily.  With good reason, most users assume that applying a ceiling plan view template (i.e. Mechanical Ceiling), would cause the ceiling to appear.  Unfortunately, Underlay Orientation is not controlled by a view template; it has to be manually changed in the view to Reflected Ceiling Plan.  This is the part that is not so obvious, which is why I employed the formatting trifecta of bold, italics and underline to emphasize it (similar to:  Mower needs gas to start!!!)

Here is a brief video illustrating this.  In the video, you’ll note that new levels are copied/monitored from the link, and new reflected ceiling plans are created from these levels.  However, no ceiling grid appears in the view.  Applying the mechanical ceiling view template doesn’t work either. It’s not until the Underlay Orientation setting is changed in the properties window that the ceiling appears.

I hope that highlighting this not-so-obvious step will help our readers avoid the frustrating process of trying to do something as basic as displaying a ceiling grid in their Revit MEP project.  At the very least, this knowledge might help you avoid acting like this guy.  Screaming at inanimate, lifeless objects like Revit seldom works; it didn’t work for me……uhhhhh.…I mean….my friend.

Oh, and by the way, to answer your question:  Yes, a wish request has been logged to have Underlay Orientation automatically set to Reflected Ceiling Plan when creating a reflected ceiling plan view.

Comments

[Pvillella]

Hi Jeremy,

Nice post! You're right -- it really is as simple as making sure you've got gas in the mower, but it can sure be aggravating until it dawns on you. I wanted to make sure my readers were aware of this setting as well, so I've written a quick article myself and linked to your post.
You can check it out here: http://www.cadsoft-consult.com/blogs/architecture/2010/09/underlay-orientation-and-rcps-with-revit-especially-revit-mep/

Thanks for a very useful Revit blog site!

Patrick Villela, LEED AP

[Jeremy Smith]

Thank you for the comments and link, Patrick!

[Gus Talbadeur]

But using underlay causes ducts to be shown hidden in reverse. Lights are shown as if they're on top of ducts. Ducts above lights are shown dashed. That is not how a mechanical plan is done.