Ceiling grid orientation and exporting

[TheChad3CI]

Reflected ceiling plans in Revit do not export in the most efficient fashion for coordination purposes specifically.  1. The grid pattern is not the same on the top of the geometry as it is on the bottom, creating confusion by modelers as to what pattern is correct depending on how they look at the model.  2. When exporting the ceilings, even drop-in ceilings with grids come through as solids.  This is far from helpful when trying to determine who is in the correct location between trade partners (think diffuser, lay-in lighting and fire protection heads). 
Currently, someone has to go into Revit, find the proper view, export it, then open the DWG in AutoCAD and explode the ceilings.  From there, I have to group the ceilings back into their respective rooms and save the DWG.  One issue with this option is that I also need to then elevate the grids to the proper elevation.  Probably more importantly, the grids are only 2D.  Having 3D extrusions of the grids would be very helpful in visualizing the placement of systems in the coordination model.

[firas007noori]

Greetings, can you share the file?

[TheChad3CI]

Good morning Firas.  Unfortunately I can't share the model due to confidentiality agreements.  

I did a lot of research online though and everything I found says the "models are acting as expected" and that this is a known topic.  Autodesk says the model is acting as it should, but it makes coordination with ceilings with grids a pain to find other ways of getting an accurate grid system for coordination.

[Simon_Weel]

To what kind of file do you export the ceiling plans?

This I don't get: The grid pattern is not the same on the top of the geometry as it is on the bottom, As far as I know, a Reflected Ceiling Plan shows the ceiling top-down, where the surface pattern is shown as if the ceiling construction is transparent.

[firas007noori]

Good afternoon, dear. I wish I had more details to search and develop an answer for such a case. I hope you get a clear answer for it soon. Please keep me updated when you get one.

Cheers,

FN

[bhavani_sankuratri]

Hello @TheChad3CI 

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[TheChad3CI]

Good morning.  I was able to clean up the file I was referring to enough to share.  I also created a couple views from above and from below, showing that the grid pattern of the ceilings do not match.  The views exist in the Revit model as well.

[firas007noori]

Greetings, dear. I am trying to add an elevation or dimension to the document, but Revit does not allow me. Most local views have been deleted. What exactly have you done to the file? The plans you provided are rendered images!
You can simply make a copy of your file, delete all the rooms, and keep this room with its ceiling and native views. You can purge the Revit Family to prevent sharing it, which will leave you with four walls and a ceiling, and the two views, one above and below the ceiling.

One more question, do you want the red and blue to match? right? If yes, then notice that the dims legs are not aligned with the ceiling grids. OR you want the top and bottom to match

Second, the grid lines are not matched in location between the bottom and top, which I believe is your primary concern

I have done this example _ 2 RCP plans: one to see under the ceiling object and the other is to at the RCP and it is above it (not the four squares are not showing as they are under the ceiling), look at the RCPs view range, they might help you, and the grid lines are the same

 

 

 

Try these settings, mate, and I am sorry I could not understand the Revit file you sent me, as it has pictures instead of the actual ceiling object in the 2D plan.

I am starting to suspect that you have a corrupted Revit file or template, as it sometimes causes such errors. Or your Dim legs were not accurately aligned to the ceiling grids, because I got in the file I built, both top and bottom are matching, and also both right and left grid ceiling lines are matching too (at the same view and in top and bottom).

Another suggestion, is to go ahead start the "Metric Default.RTE" build four walls and a ceiling, test the settings and see how the ceiling grids should act, if the same setting used in both files (the one you are working one, and the new one) then, you either has a curruted file, or you have added two ceiling in the same place, same location, each has different ceiling grids (so may be delete the ceiling itself and see if you still can see the ceiling grids), and finally check your dim legs are correctly placed and aligned with the ceiling grids.

Good Luck and all the best,

Firas Noori

[RLY_15 · Accepted solution]

Unfortunately, the top/bottom hatch mismatch is typical (likely unexpected) Revit behavior. I don't generally see it as a problem, but it's been noted when viewing ceilings in 3D views as, honestly, annoying.

I don't recall the grid placement being exposed in the Revit API, so you can't even attempt to programmatically align the top/bottom to each other. And physically modelling the tiling for accuracy is resource-intensive.

Not a solution, but confirmation that you're not alone on this one.

[TheChad3CI]

Hi Firas.
I "purged" almost everything from the model I received from the design team in order to share the geometry in question but keep the project confidential.  I left the 3D geometry of the ceiling in the model and create 2 views, one from the top and one from the bottom, both dimensioned to show the difference in the top and bottom faces of the ceiling.  Ideally, I want the top and bottom faces to match as far as the grid pattern is concerned.  I would also like the geometry to be exported in a fashion where my coordination team can snap to the grid lines, but the process needed to accomplish this is long and drawn out, requiring work in AutoCAD to make the linework export match the grid pattern illustrated on the issued documents.
Sorry, I should have been clearer on my first request, I get these models from design teams and the information that comes from the models is inconsistent.

[TheChad3CI]

Thank you.  I've seen it over and over again, and I honestly do not understand the reason behind it.  For a coordination team, it does cause a bit of a hurdle for it to be useful for aligning systems such as lights and diffusers.

[RLY_15]

The reason is just that hatch patterns are surface-dependent, and that it's a miracle we can even adjust the one responsible for the RCP view alignment (hyperbole).