Hi,
I'm a little bit confused with the concept of Families, as I'm starting with Revit, and I have a question related to both API and Family Parameters in a more general context.
What I noticed : I created a small geometry in Architecture (4 walls), and exported it in IFC format. Then I reloaded it in Revit Architecture and played with the API to do some operations on that geometry. One thing I did while using the API on this geometry was to use the method "LookupParameter()" on walls, to access some parameters. And One of these parameters I accessed was 'IsExternal'.
Ok, but now, I downloaded an other IFC File I found on internet, which is a small house, and I wanted to do the same kind of operations on it. It all worked well until I tried to access this 'IsExternal' parameter on the walls... this parameter doesn't exist anymore for these walls.
I digged a little bit and realized that 'IsExternal' is actually an IFC parameter that Revit adds when exporting to IFC. I know that because I exported the house from Revit to IFC, then reloaded it, and ... 'IsExternal' is now there (except that it's set to 'True' everywhere... but no matter).
Now the question 
:
Can I add parameters to a family (in this case the 'wall' family, I guess) if I want to ? I think the answer is yes, but then, how ? Do I have to be in the 'Family mode' of Revit, or can I do that directly from withinside a project ?
The thing is that I see the workflow as the following : loading an IFC - checking is the 'IsExternal' parameter is there or not - if not, adding it to all walls - doing my other operations - exporting again to IFC.
If anyone can help I'd be grateful !
Arnaud.
