Get Instance Parameter from a set of Family Types

[DavidMena]

Hi everyone.
I have the following issue working with Python Node:
I’m getting a list of elements (in this case Structural framing and columns), filtered them according to a Description (which is a Type parameter value). What I get is a list of Family Types, but when I try to apply a LookupParameter method in order to get the “Volume” from each of the items in that list I only get null values.
I guess that this is because “Volume” is an instance parameter while my list is made of Family Types. So, how can I get the instance parameter “Volume” from this "Family Types"list?
This is the code I’ve written inside Python Node:

import sys
import clr
clr.AddReference('RevitAPI')
import Autodesk
from Autodesk.Revit.DB import *

clr.AddReference('RevitServices')
import RevitServices
from RevitServices.Persistence import DocumentManager
doc = DocumentManager.Instance.CurrentDBDocument

clr.AddReference('DSCoreNodes')
from DSCore import Math

#Get Elements
elemSecVar = []
columnas = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_StructuralColumns).WhereElementIsNotElementType()
for columna in columnas:
	id = columna.GetTypeId()
	elemento = doc.GetElement(id)
	descripcion = elemento.LookupParameter("Description").AsString()
	if descripcion is not None and descripcion.Contains("SV"):
		elemSecVar.append(elemento)
vigas = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_StructuralFraming).WhereElementIsNotElementType()
for viga in vigas:
	idv = viga.GetTypeId()
	elementoV = doc.GetElement(idv)
	descripcionV = elementoV.LookupParameter("Description").AsString()
	if descripcionV is not None and descripcionV.Contains("SV"):
		elemSecVar.append(elementoV)

lista = []
for elem in elemSecVar:
	elemento = elem.LookupParameter("Volume")
	lista.append(elemento)
	

OUT = lista

Any help will be very appreciated

[c.poupin]

Hello @DavidMena

you need to get an instance from type to get instance parameter
a simple example

e = UnwrapElement(IN[0])
eTypeId = e.GetTypeId()
filter = FamilyInstanceFilter(doc, eTypeId)
instance = FilteredElementCollector(doc).OfClass(FamilyInstance).WherePasses(filter).FirstElement()

[DavidMena]

Thank you for your help @c.poupin . The problem is that first I’m getting a list of family Types that contain a certain string as Description (Which is Type Parameter), then I try to iterate over that list to apply the Instance Filter and, to begin with, it returns me only invalid values as TypeId as you can see in the image. I guess the approach is probably wrong from the beggining, so I would aprreciate if you cast a bit of light over my confusion. Thanks!

[c.poupin]

I’m not sure what end result you want but you can try this (not tested, no model)

import sys
import clr
clr.AddReference('RevitAPI')
import Autodesk
from Autodesk.Revit.DB import *

clr.AddReference('RevitServices')
import RevitServices
from RevitServices.Persistence import DocumentManager
doc = DocumentManager.Instance.CurrentDBDocument

clr.AddReference('DSCoreNodes')
from DSCore import Math

#Get Elements
elemSecVar = []
columnas = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_StructuralColumns).WhereElementIsNotElementType()
for columna in columnas:
	id = columna.GetTypeId()
	elemento = doc.GetElement(id)
	descripcion = elemento.LookupParameter("Description").AsString()
	if descripcion is not None and descripcion.Contains("SV"):
		elemSecVar.append(elemento)
vigas = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_StructuralFraming).WhereElementIsNotElementType()
for viga in vigas:
	idv = viga.GetTypeId()
	elementoV = doc.GetElement(idv)
	descripcionV = elementoV.LookupParameter("Description").AsString()
	if descripcionV is not None and descripcionV.Contains("SV"):
		elemSecVar.append(elementoV)

lista = []
for elemTyp in elemSecVar:
	filter = FamilyInstanceFilter(doc, elemTyp.Id)
	all_elements = FilteredElementCollector(doc).WherePasses(filter).WhereElementIsNotElementType()
	for elem in all_elements:
		para = elem.LookupParameter("Volume")
		if para is not None:
			lista.append(elemento.AsDouble()) # or AsString() ?
	
OUT = lista

[DavidMena]

Hi @c.poupin . Thanks!
Now it is returning values, but for some reason it is returning more than 2000 values when I only have 90 elements in my model

[Kulkul]

Hi @DavidMena

No need to iterate again. You can directly get volumes after you filter familyinstances by Description name (“SV”) this way:

import sys
import clr
clr.AddReference('RevitAPI')
import Autodesk
from Autodesk.Revit.DB import *

clr.AddReference('RevitServices')
import RevitServices
from RevitServices.Persistence import DocumentManager
doc = DocumentManager.Instance.CurrentDBDocument

#Get Elements
elemSecVar = []
columnas = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_StructuralColumns).WhereElementIsNotElementType()
for columna in columnas:
	id = columna.GetTypeId()
	elemento = doc.GetElement(id)
	descripcion = elemento.LookupParameter("Description").AsString()
	if descripcion is not None and descripcion.Contains("SV"):
		elemSecVar.append(columna.LookupParameter("Volume").AsDouble())
		
vigas = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_StructuralFraming).WhereElementIsNotElementType()
for viga in vigas:
	idv = viga.GetTypeId()
	elementoV = doc.GetElement(idv)
	descripcionV = elementoV.LookupParameter("Description").AsString()
	if descripcionV is not None and descripcionV.Contains("SV"):
		elemSecVar.append(viga.LookupParameter("Volume").AsDouble())

OUT = elemSecVar

[DavidMena]

That was it!
As you said, no need to iterate again. Just append the element to the list after filtering it. It worked perfectly!
Thanks