Revit RCP Demo Issues - Am I crazy?

[cmroz]

After searching on the forums all morning, I decided this was worth asking.

My Goal: Switch out (demo) an existing light fixture and replace with a new one.

Here was my test: Create a brand new project with the (non-modified) Arch template. Create an existing room (4 generic walls) with a stock 2x4 grid ceiling. Place an existing stock 2x4 fixture in the ceiling. Set light to be demo'd in the new construction phase. Duplicate RCP and set phase to new construction. Try to place a new light in the same location. For me, this resulted in all kinds of errors. "Cannot cut host", "Circular references".

Even inserting an existing recessed light in the grid, demoing it, and then trying to put a new recessed light in the same ACT panel results in these same errors.

I have found an odd work around, but it is not at all convenient or consistent. Not working on most projects.

Any ideas?

Sorry for the long screencast, messed up the first time through, skip to 2:45 for the issue (no way to trim the video after uploading).

Thanks,

Chris

[kmfuhrman]

When you place the "new" fixture, is the phase of the family set to New Construction (check after you load, but before you click to place it)?

[cmroz]

Unfortuanlety I cannot change the phase before placeing the fixture. However, I am placing it with the view set to the New Construciton phase, so it defaults to the correct phase (checking the phase after placement).

[RDAOU]

I have noticed the same issue; I cannot explain why the architectural fixtures behave like that but if you use the same fixtures from Lighting>MEP>Internal instead of Architectural>Internal it will solve this issue. (At least it did for me)

Couple of more differences noted between architectural lighting behavior vs MEP

1. (On Existing Plan) Phase the Architectural Fixture to be demolished in New construction - Now switch to new construction view and hover the cursor over the ceiling grid (Result: Its invisible but it still resides there - you can see the mouse over tip)

    - MEP not - it gets completely cut out in New Construction

2. Architectural Lighting Family is hosted by ceiling ... MEP hosted by Face (There is something in this I believe that explains the above behavior) The can't cut host when using architectural fixture is because host is another lighting fixture. part of the ceiling...If you demolish whole ceiling (not just the arch lighting fix) then in new construction you can insert a new ceiling and new light ... this works

Haven't given it much thought than that  cuz I thought it was only me but now I see you got the same issue.

[cmroz]

Thanks RDAOU - that's interesting that the MEP fixtures seem to work. I'm using a handful of fixtures from manufactures, and those all seem to be Architectural as opposed to Mech because they do not work in this test either.

It seems like a bug in the behavior of the ceiling element (or phasing) - not necessarily a limitation of the software... certainly demo'ing a light fixture and replacing it with a new one is a pretty common procedure.

[RDAOU]

@cmroz It is indeed the family behavior Ceiling hosted (Architectural) Vs. Face Hosted (MEP) ... It surely have an explanantion and one should be able to tweek it but need some time to look into it.

Unfortunatly not many know this and one definitly wont find it in a book or tutorial; hence its quite a shock for those reading up on phasing...I hope you can mark it as solution so others may find there way to this post easily. I am adding also a screencast showing this difference in behavior (Just incase my words failed me when I tried to explain above)

[chrisplyler]

I suspect this behavior may be due to the demolition of the Architectural fixture resulting in a ceiling infill element being created. Then, unless the new fixture is placed such that it overlaps the boundry between the ceiling and its infill element, it can't figure how to mount itself.

Honestly, I don't understand why there even is such a thing as an Architectural light fixture. Why not use proper MEP fixtures all the time?

[RDAOU]

Because Architects are architects and Engineers are engineers :)... They are two different family templates one is face hosted (MEP)  and one Ceiling Hosted (Arch) which makes sense...If one thinks from the architect's perspective!

Anyhow:  another fix of this behavior is to open the Architectural lighting fixture in Family editor and then go to Family Category and Parameters and check Cut with Voids when loaded and reload into the project...This seems to solve this issue

[cmroz]

Thanks for the responses everyone. I thought I was overlooking some basic functionality of phasing or the software - but I guess not.

I'm being prompted by a member to select one of these responses as a "solution", but I don't really see a valid solution. Using MEP components in the Arch template makes little sense, and given (outside of this basic example I used here to illustrate the point) most manufacturer's fixture files are not MEP fixtures...

That being said I do really appreciate people taking the time to respond.

If I should select one of these answers as a possible temporary workaround, I can do that. Not sure if that's how the forums usually work?

[RDAOU]

I don't think its MEPvs Architectural... its about using different type of family template or more to say the right template for the right purpose. As mentioned above Arch and MEP are base on two different templates which behave differently and that is not a glitch that's for a specific purpose.

Manufacturers files can be called anything it's the family template they are using and the behavior of that template what makes the difference... It's same probably the same answer for the question "why can't I place that library door on a face element, if I can do it with the curtain wall door then why not with other doors families" hence, using the right family is not a workaround.

yet again 🙂 I might be wrong...right?

[chrisplyler]

I still don't see the need for Architectural fixtures separate from the MEP fixtures. Why can't an architect as easily load an MEP one from the library as an Arch one?

Even if they - or the manufacturers - don't want to go to the trouble to create connectors and all the electrical parameter info, they could still model the 3D form in an MEP family just as easily as they could in an Arch family. Would solve the headache of copy/monitor too. And I can't fathom any way in which ceiling based is better than face based.

[RDAOU]

I'm just going to give up lol

I just thought I would clarify the difference but you can even use an orange monkey with red ears and purple tail if it suits the purpose and gets you model to work

Sent from my iPhone

[kmfuhrman]

I'll agree with you on the ceiling vs. face based. I think it's just what the architectural side is used to with Revit. As far as not using MEP fixtures, there used to be some issues with the way the MEP fixtures rendered...again probably a carryover from previous releases. The MEP fixtures are also geared toward MEP schedules and have a lot of extraneous information and parts that the architects just don't need. The architectural fixtures aren't as hefty and keep the model size smaller. JMHO. Can't we all just get along? 

[chrisplyler]

I'm sure it's a holdover from before Revet had any electrical funtionality.

I get along with everybody...

...everybody who does things my way.

HA!