Get Bottom Face of Door

[Anonymous]

Hi,

I need to get the bottom face of a door (highlighted in the image below)

However, I have no idea of how one could do this. I have some experience of getting different faces on Walls, but I cannot translate it to Doors/Family Instances. 

Thanks in advance! 

[RPTHOMAS108]

likely bottom face with have the smallest Z value for face origin and have a normal similar to 0,0,-1.

Have a look in RevitLookup, there could be many bottom faces in family instances, so no standard way. Doors should be easy though because they are always vertical.

[Anonymous]

Choosing which face is the easy part, but how do I get all of the faces in the first place?

[RPTHOMAS108 · Accepted solution]

It is similar to extracting geometry from Walls only real difference is that unmodified FamilyInstances have a top level GeometryInstance that contains the geometry primitives. The process for modified (cut/joined) FamilyInstances is the same as system families such as walls.

There is a good example under Element.Geometry in RevitAPI.chm. This example extracts both Solids and Curves but you can take out the curves part.

For each solid you can then use Solid.Faces collection.