Revit X- files

Mechanical and Electrical Reflected Ceiling Plan (RCP) Strangeness

There is a strange behavior, when a RCP’s Discipline parameter is set to either Mechanical or Electrical, that has caused a problem for us on a couple of occasions.

Normally the view parameter Underlay Orientation is grayed out and not available when there is no Underlay selected. However, when a view (any view) is set to Mechanical or Electrical, that parameter becomes active and can be changed. This hasn’t caused a problem with floor plans yet. But I see how it could.

While it’s bad enough that a user could change this parameter to plan in a RCP (or to RCP in plan even) what makes this truly sinister is that the default for a NEW REFLECTED CEILING PLAN is PLAN for this parameter (that’s why it hasn’t caused issues for plans, it’s the default there as well.)

We have had occasions where the ceiling just no longer shows (as expected when set to plan) or in a linked model it was just showing the ceiling grid in the wrong place. Which is far worse, as we found when we went to coordinate light fixtures, air terminals and ceilings. YIKES!!!!!

So, it’s imperative that anyone who makes a new ceiling plan that is to be used for one of these disciplines needs to change that parameter to read Reflected Ceiling Plan.

To make matters more difficult, Revit has decided that this parameter is not something that you would want to set as part of a view template, even though you can set it’s Underlay (hmmmmm, that makes sense. I can’t count the times I’ve wanted to have multiple view have the same Underlay. Well only because it hasn’t happened.)

And to really confuse the user, when the same view (with the incorrect value for Underlay Orientation) is set to COORDINATION or ARCHITECTURAL for it’s Discipline… of course it displays correctly (exactly as you expected, right?) Now, don’t be silly and think that it has somehow magically changed the incorrect value. No, Revit has just decided to ignore it.'

Have I logged this as a support request? No. I probably should, but I’ve been busy fixing my own issues…

The Revit X-Files

The truth is out there... I think.

So this is a new category of posts here at Big Bad BIM. Reminiscent of Revit OpEd's Department of Unfair. This will be the repository for all the freaky,weird, off-the-wall Revit stuff that just drives me CRAZY!!!


I think Autodesk calls these "service requests." Ok, ok, I'll try to log those too.


First installment comes from our Mechanical Engineering department. One of our user's was trying to use the "Tag All Not Tagged" tool to tag all of the ceilings in a view. He just couldn't get it to work. He could tag them one at a time, but not all.


Wondering if it was something related to that particular project, I tried it in a view that was set to the Architetural discipline as opposed to the Mechanical discipline. Sure enough, no problem. I changed the view in question to an Architetual discipline. Tagged All Not Tagged and changed it back. Worked great. Work-around? You bet, but we have lots of those.

Back at my desk, I wanted to make sure I hadn't missed something. So I compared the element properties of a couple of views.Here are the results (notice in particular the "underlay orientation"):


Architectural Discipline:



Mechanical Discipline:




Note: the Mech view didn't default to "Plan" for the Underlay Orientation. I changed it. I CHANGED IT!!! You shouldn't be able to do that. That parameter allows you to underlay a ceiling plan in a plan view (so you can coordinate overhead information with your floor plan.) I don't think we were meant to access this in a ceiling plan.

Are these two conditions related. Is it a programming bug? Aliens that have it in for HVAC designers? Who knows, but it sure is weird (not to mention frustrating.)


Here a couple of ceiling related videos. First is a video that shows the workaround mentioned above. The second is a video that shows how to apply filters (powerful little buggers, those filters) that make "non-standard" ceiling heights really "pop," which really helps when coordinating information in the model.