Creating Dimensions for Linked Models

Creating Dimensions for Elements with Solid Geometry like Floors

Today, while answering a question on the Revit API Forum about how to get the reference of a linked model to implement dimensioning Reference to Grid and Level from link, I used the CreateLinkReference(doc) method to get it directly, but the dimension creation failed.
The error reported an invalid reference. Later, I debugged and successfully dimensioned using a manually created link reference, so I suspected the issue specific to the acquired reference. Checking the reference string in the background revealed inconsistencies.

![Image Description](https://cdn.bimath.com/blog/pg/Snipaste_2026-01-04_16-02-02.png)

Later, I saw this article Revit Handling Linked File Dimension Reference. After modification, dimension creation was successful. It seems that the issue was with the reference-stable conversion, causing the direct acquisition to fail.

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var floor = RevitCommandData.Document.GetElement(5676918) as Floor;
            var reference = floor.GetTopFaceReferences().First();

            var linkInstance = RevitCommandData.Document.GetElement(5678360) as RevitLinkInstance;
            var linkDoc = linkInstance.GetLinkDocument();
            var targetLinkEle = linkDoc.GetElement(5677607) as Floor;
            var linkFace =
                targetLinkEle.GetGeometryObjectFromReference(HostObjectUtils.GetTopFaces(targetLinkEle).First()) as
                    Face;
            var linkRef = HostObjectUtils.GetTopFaces(targetLinkEle).First().CreateLinkReference(linkInstance);
            var str = linkRef.ConvertToStableRepresentation(RevitCommandData.Document);
            var str2 = referenceLink.ConvertToStableRepresentation(RevitCommandData.Document);
            var strs = str.Split(':').ToList();
            var newStr = $"{strs[0]}:0:RVTLINK:{strs[2]}:{strs[3]}:{strs[4]}";
            var newReference = Reference.ParseFromStableRepresentation(RevitCommandData.Document, newStr);
            var testRef = newReference.ConvertToStableRepresentation(RevitCommandData.Document);
          
            TransactionUtils.Execute(RevitCommandData.Document,new Action<IDisposable>(x =>
            {
                var referenceArray = new ReferenceArray();
                referenceArray.Append(reference);
                referenceArray.Append(newReference);
                var fakeLine = Line.CreateUnbound(new XYZ(-49.469472958128, 1769.33005941939, 209.147513214079),
                    -XYZ.BasisZ);
                var dim = RevitCommandData.Document.Create.NewDimension(RevitCommandData.ActiveView, fakeLine,
                    referenceArray);
            }),"test");

Creating Dimensions for Non-Solid Elements like Levels and Grids

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#region Create Link Level And Grid Dimension
           //ModelLine
           // var line = RevitCommandData.Document.GetElement(5679235) as ModelLine;
           // var linkInstance = RevitCommandData.Document.GetElement(5678360) as RevitLinkInstance;
           // var linkDoc = linkInstance.GetLinkDocument();
           // var referenceLine = line.GeometryCurve.Reference;
           // //Linked Grid
           // var linkGrid = linkDoc.GetElement(5684684) as Autodesk.Revit.DB.Grid;
           // var linkGridRefLine = (linkGrid.Curve.Reference).CreateLinkReference(linkInstance);
           // var linkGridStr = linkGridRefLine.ConvertToStableRepresentation(RevitCommandData.Document);
           // var strs = linkGridStr.Split(':').ToList();
           // var completeGridRef = $"{strs[0]}:0:RVTLINK:{strs[2]}:{strs[3]}:{strs[4]}";
           // var targetRef = Reference.ParseFromStableRepresentation(RevitCommandData.Document, completeGridRef);
           // // Local Level
           // var level = RevitCommandData.Document.GetElement(5672502) as Level;
           // var levelRefPlane = new Reference(level);
           // //Link Level
           // var linkLevel = linkDoc.GetElement(5672528) as Level;
           // var linkLevelRefLine = (new Reference(linkLevel)).CreateLinkReference(linkInstance);
           // var linkLevelStr = linkLevelRefLine.ConvertToStableRepresentation(RevitCommandData.Document);
           // var linkRefSplits = linkLevelStr.Split(':');
           // var completeLevelRef = $"{linkRefSplits[0]}:0:RVTLINK:{linkRefSplits[2]}:0:SURFACE";
           // var targetLevelRef = Reference.ParseFromStableRepresentation(RevitCommandData.Document, completeLevelRef);
           //
           //
           // TransactionUtils.Execute(RevitCommandData.Document , new Action<IDisposable>(x =>
           // {
           //     //Create Link-Level And Local-Level
           //     // var array = new ReferenceArray();
           //     // array.Append(levelRefPlane);
           //     // array.Append(targetLevelRef);
           //     // var l = Line.CreateUnbound(new XYZ(160.658709208543, -55.1818640250467, 39.7924116653103), -XYZ.BasisZ);
           //     // var dimLevel = RevitCommandData.Document.Create.NewDimension(RevitCommandData.ActiveView, l, array);
           //     //Create Link-Grid And ModelLine
           //     var array2 = new ReferenceArray();
           //     array2.Append(referenceLine);
           //     array2.Append(targetRef);
           //     var l2 = Line.CreateUnbound(new XYZ(34.4348591859389, 52.0854280621026, 0), XYZ.BasisY);
           //     var dimGrid = RevitCommandData.Document.Create.NewDimension(RevitCommandData.ActiveView, l2, array2);
           // }),"test");
           
           #endregion