Revit 2020 API BasePoint - Unable to access parameter info of linked models.

[Dan_Mapes]

We have been using a python script to get the BasePoint info from all linked models in a project. We use this to create a project dashboard showing all linked models and their associated location information. In 2020 this stopped working and I need to figure out a solution.

In the 2020 API we cannot access the Built in parameters for BasePoint when using GetLinkedDocument()

Is there another method to get this info from a linked model in the 2020API?

linkDocuments = []
for linkType in linkTypes:
if DB.RevitLinkType.IsLoaded(doc, linkType.Id):
     linkDoc = None
     for li in linkInstances:
           if li.GetTypeId().IntegerValue == linkType.Id.IntegerValue:
                    linkDoc = li.GetLinkDocument()
            if linkDoc is not None:
                linkDocuments.append(linkDoc)       

basepoints = DB.FilteredElementCollector(linkDoc)\
            .OfClass(DB.BasePoint)
        basePoint = None
        surveyPoint = None
        # print(modelName)
        for e in basepoints:
            if e.IsShared:
                surveyPoint = e
                break
        for e in basepoints:
            if not e.IsShared:
                if e.get_Parameter(DB.BuiltInParameter.BASEPOINT_ANGLETON_PARAM) is not None:
                    basePoint = e
        surveyPointNS, surveyPointEW, surveyPointElev = (
            round(surveyPoint.get_Parameter(
                DB.BuiltInParameter.BASEPOINT_NORTHSOUTH_PARAM).AsDouble(), 3),
            round(surveyPoint.get_Parameter(
                DB.BuiltInParameter.BASEPOINT_EASTWEST_PARAM).AsDouble(), 3),
            round(surveyPoint.get_Parameter(
                DB.BuiltInParameter.BASEPOINT_ELEVATION_PARAM).AsDouble(), 3)
        )

[Anonymous]

I have same issue with you. Did you solve it?

[Dan_Mapes]

No I still have not found a solution to this.

[Yien_Chao]

try to use this instead:

.Basepoint[0]

Or better :

BuiltInCategory.OST_ProjectBasePoint

BuiltInCategory.OST_SharedBasePoint

if you use .Basepoint, you will get a list of points (project and shared)

[RPTHOMAS108]

You can use static methods:

BasePoint.GetProjectBasePoint(Document)

BasePoint.GetSurveyPoint(Document)

BasePoint class also has the following related properties:

Position

SharedPosition

IsShared

What you'll find is that instances of BasePoint with category OST_ProjectBasePoint do not have the following parameters attached if they are from a linked document:

BuiltInParameter.BASEPOINT_NORTHSOUTH_PARAM

BuiltInParameter.BASEPOINT_EASTWEST_PARAM

BuiltInParameter.BASEPOINT_ELEVATION_PARAM

BuiltInParameter.BASEPOINT_ANGLETON_PARAM

I don't know the reason for that but I also don't know what bearing these things have on how the link is orientated in the host project? You could have an infinite number of positions for project base point in a link project but still achieve the same relative position between the link and it's host.  Maybe it is important for IFC, I don't know. I've worked on project where I set project north 180 degrees opposite from the architect's project north (as that was the elevation more relevant to us) in the end the links still came together in the correct position and orientation using shared coordinates. Also important to remember that there is an active site and same link type can be placed in multiple alternate locations, so I don't know how that relates to your intended task.

[TripleM-Dev.net]

In Revit 2020 a third BasePoint exists: BuiltinCategory.OST_IOS_GeoSite in addition to the 2 others categories mentioned by @Yien_Chao 

This third point, IsShared property = False, and doesn't have the BuiltinParameter.BASEPOINT_ANGLETON_PARAM.

There isn't a break in the second loop, so the retrieved BasePoint variable is overwritten by the third basepoint.

Stop the loop as soon as the BasePoint is retrieved OR compare against the BuiltinCategory value

- Michel

[moj]

Did anyone solve this?

[moj]

I solved it this way:

// Get the current project location
ProjectLocation currentLocation = m_selectedLinkedDocument.ActiveProjectLocation;

// Create a 0,0,0 origin
XYZ origin = new XYZ();

// Get the project position
ProjectPosition projectPosition = currentLocation.GetProjectPosition(origin);

// Get the Project Base Point parameters
double northSouth = projectPosition.NorthSouth;
double eastWest = projectPosition.EastWest;
double elevation = projectPosition.Elevation;
double trueNorth = projectPosition.Angle;