Geometry requirements for Mass to create By Face elements

[divanciucova]

Hi,

Plenty of times when creating a Roof by Face or Wall by Face elements, there's an error (ex. 'can't create roof') without any guidance of what went wrong.

Testing plenty of examples of success and failure I wasn't able to figure what Revit wants.

Having an explanation would help make workflows more stable instead of hitting a dead end after long hours of work.

Thanks in advance,

Daria

[constantin.stroescu · Accepted solution]

you have to take in consideration when you choose to make Wall by Face or Roof by Face , the following:

• Wall by Face works for almost all surfaces except the Horizontal ones ( you have to use Roof by Face for them)
• Roof by face works for most of close to horizontal but not for vertical or close to vertical surfices. As you can see in my screenshot, when the Surface tends to vertical the Rafter Cut (Plumb Cut )grows and tends to infinite..and that is impossible to be calculated

So , Wall by Face has more chances to work...

[divanciucova]

thanks for a prompt response.

- is there a check that I can perform to test if the surface is 'horizontal enough' for a roof?

Revit doesn't let me even select the roofs that are 'too vertical', I'm guessing the selection filter is based on some calculation.

- these two shapes are based on the same geometry but coming from different sources (left is Rhino Inside Direct Shape, right is a revit family built manually). Why would one work and the other one - not?

upd. sorry, realized the second part of the question is too vague, will come back with more details.