Edit Assembly and Compound Structure "Variable" Check Box

[Anonymous]

Hello!  I am a design student, in my first term with REVIT.  I am finally beginning to understand and enjoy the program.  I took to AutoCAD much quicker than REVIT and was able to not only navigate my way through the projects, but go above and beyond the requirements, as well as do extra research, which helped my colleagues with full time jobs on top of their full class loads and families.  REVIT is not as user friendly as AutoCAD, but now that I am beginning to figure out the quirks, I am enjoying playing with the different aspects of design REVIT offers, such as the Edit Assembly/Compound Structure feature that allows you to build your own Walls, Floors, or Roofs.  My instructor calls them 'sandwiches'!  However, there is a column (the last column) that we don't understand the purpose of, and I cannot find any reference to it in the help section or the videos.  It is titled "Variable".  From what I can tell, you can only check it once per assembly/sandwich, but it didn't do anything obvious to the floor assembly that I applied it to, so I can't figure out what it does.  Can anyone tell me what this means or what it is for?  Thanks everybody!

[L.Maas]

When you do a modify sub-elements on a floor and create a slope in there (e.g for drain) it use the settings of a variable layer (if set).

In this case you can assign which layer should be variable. In the screenshot I have three similar floors. The first instance has the first layer variable in the second instance has the third layer variable. In the third example it has no layers variable.

[Anonymous]

Thank you for responding to my question! You obviously have a level of knowledge in architecture and construction way beyond my own. I'm still unclear on what exactly the "variable" check box does, or maybe I just don't understand how to create a slope in a Compound Structure. Did the slope occur because of the drain, thereby the "variable" would be the location of the drain in the Compound Structure? If you click the "variable" box on a particular layer, you are specifying that the "variable", or object placed in the Compound Structure only effects said layer or layers, if you do not click "variable", the object effects all the layers? I'm taking Algebra this term, as well, so that may be causing a correlative association, which might be completely off base. I'm just trying to figure this all out! Thanks, again!

[L.Maas]

Basically what happens is that in the floor type you set if and and in that case which layer is 'potentially' variable.  So with this setting alone you will still have a flat floor. So this setting is only to indicate when something is happening to the floor how the floor should behave.

In my example I created a simple floor then I added a point. I followed by giving this point a vertical offset.

So now Revit is going to look how the floor should behave. Depending on the settings you made the floor will change according to those rules. So the whole floor might move or if a layer is set to variable only that layer is affected.

[Anonymous]

Thank you very much!  I'm sorry it took me so long to reply, but this was very helpful to all of us in the class, and we appreciate you explaining this to us so thoroughly!