fix(revit): extrusion roof and freeform elements conversion (#3045)

* Update ConvertFreeformElement.cs

* fixes extrusion roof conversion

* Update ConvertRoof.cs

Objects/Converters/ConverterRevit/ConverterRevitShared/Partial Classes/ConvertFreeformElement.cs

@@ -52,6 +52,7 @@ public ApplicationObject FreeformElementToNative(Objects.BuiltElements.Revit.Fre
         appObj.Update(status: ApplicationObject.State.Failed);
         return appObj;
       }
+
       Doc.LoadFamily(tempPath, new FamilyLoadOption(), out var fam);
       var symbol = Doc.GetElement(fam.GetFamilySymbolIds().First()) as DB.FamilySymbol;
       symbol.Activate();
@@ -186,10 +187,12 @@ private string CreateFreeformElementFamily(List<DB.Solid> solids, string name, o
         t.Start();
 
         //by default free form elements are always generic models
-        BuiltInCategory bic = BuiltInCategory.OST_GenericModel;
-        Category cat = famDoc.Settings.Categories.get_Item(bic);
+        Category cat = null;
         if (freeformElement is not null && !string.IsNullOrEmpty(freeformElement.subcategory))
         {
+          BuiltInCategory bic = BuiltInCategory.OST_GenericModel;
+          cat = famDoc.Settings.Categories.get_Item(bic);
+
           //subcategory
           if (cat.SubCategories.Contains(freeformElement.subcategory))
           {
@@ -204,7 +207,10 @@ private string CreateFreeformElementFamily(List<DB.Solid> solids, string name, o
         foreach (var s in solids)
         {
           var f = DB.FreeFormElement.Create(famDoc, s);
-          f.Subcategory = cat;
+          if (cat is not null)
+          {
+            f.Subcategory = cat;
+          }
         }
 
         t.Commit();

Objects/Converters/ConverterRevit/ConverterRevitShared/Partial Classes/ConvertGeometry.cs

@@ -743,9 +743,17 @@ public XYZ GetPerpendicular(XYZ xyz)
       var xn = new XYZ(1, 0, 0);
 
       if (ixn.IsAlmostEqualTo(xn))
+      {
         xn = new XYZ(0, 1, 0);
+      }
+      else if (ixn.Negate().IsAlmostEqualTo(xn))
+      {
+        xn = new XYZ(0, -1, 0);
+      }
+
+      var cross = ixn.CrossProduct(xn);
 
-      return ixn.CrossProduct(xn).Normalize();
+      return cross.Normalize();
     }
 
     public Geometry.Surface FaceToSpeckle(DB.Face face, DB.BoundingBoxUV uvBox, Document doc, string units = null)

Objects/Converters/ConverterRevit/ConverterRevitShared/Partial Classes/ConvertRoof.cs

@@ -29,28 +29,35 @@ public ApplicationObject RoofToNative(Roof speckleRoof)
         return appObj;
       }
 
-      // outline is required for roofs, except for Extrusion roofs
-      CurveArray outline = null;
-      if (speckleRoof.outline is null)
+      // outline is required for footprint roofs
+      // referenceLine is required for for Extrusion roofs
+      CurveArray roofCurve = null;
+      if (speckleRoof is RevitExtrusionRoof extrusionRoof)
       {
-        if (speckleRoof is not RevitExtrusionRoof)
+        if (extrusionRoof.referenceLine is null)
         {
-          appObj.Update(status: ApplicationObject.State.Failed, logItem: "Roof outline was null");
+          appObj.Update(status: ApplicationObject.State.Failed, logItem: "Extrusion roof profile was null");
           return appObj;
         }
+        roofCurve = CurveToNative(extrusionRoof.referenceLine);
       }
       else
       {
-        outline = CurveToNative(speckleRoof.outline);
+        if (speckleRoof.outline is null)
+        {
+          appObj.Update(status: ApplicationObject.State.Failed, logItem: "Roof outline was null");
+          return appObj;
+        }
+        roofCurve = CurveToNative(speckleRoof.outline);
       }
 
       // retrieve the level
       var levelState = ApplicationObject.State.Unknown;
       double baseOffset = 0.0;
       DB.Level level = speckleRoof.level is not null
         ? ConvertLevelToRevit(speckleRoof.level, out levelState)
-        : outline is not null
-          ? ConvertLevelToRevit(outline.get_Item(0), out levelState, out baseOffset)
+        : roofCurve is not null
+          ? ConvertLevelToRevit(roofCurve.get_Item(0), out levelState, out baseOffset)
           : null;
 
       var speckleRevitRoof = speckleRoof as RevitRoof;
@@ -72,6 +79,7 @@ public ApplicationObject RoofToNative(Roof speckleRoof)
       {
         case RevitExtrusionRoof speckleExtrusionRoof:
         {
+          // get the norm
           var referenceLine = LineToNative(speckleExtrusionRoof.referenceLine);
           var norm = GetPerpendicular(referenceLine.GetEndPoint(0) - referenceLine.GetEndPoint(1)).Negate();
           ReferencePlane plane = Doc.Create.NewReferencePlane(
@@ -81,16 +89,10 @@ public ApplicationObject RoofToNative(Roof speckleRoof)
             Doc.ActiveView
           );
 
-          // get level if null
-          if (level is null)
-          {
-            level = ConvertLevelToRevit(referenceLine, out levelState, out baseOffset);
-          }
-
-          //create floor without a type
+          //create floor without a type with the profile
           var start = ScaleToNative(speckleExtrusionRoof.start, speckleExtrusionRoof.units);
           var end = ScaleToNative(speckleExtrusionRoof.end, speckleExtrusionRoof.units);
-          revitRoof = Doc.Create.NewExtrusionRoof(outline, plane, level, roofType, start, end);
+          revitRoof = Doc.Create.NewExtrusionRoof(roofCurve, plane, level, roofType, start, end);
 
           // sometimes Revit flips the roof so the start offset is the end and vice versa.
           // In that case, delete the created roof, flip the referencePlane and recreate it.
@@ -99,14 +101,14 @@ public ApplicationObject RoofToNative(Roof speckleRoof)
           {
             Doc.Delete(revitRoof.Id);
             plane.Flip();
-            revitRoof = Doc.Create.NewExtrusionRoof(outline, plane, level, roofType, start, end);
+            revitRoof = Doc.Create.NewExtrusionRoof(roofCurve, plane, level, roofType, start, end);
           }
           break;
         }
         case RevitFootprintRoof speckleFootprintRoof:
         {
           ModelCurveArray curveArray = new ModelCurveArray();
-          var revitFootprintRoof = Doc.Create.NewFootPrintRoof(outline, level, roofType, out curveArray);
+          var revitFootprintRoof = Doc.Create.NewFootPrintRoof(roofCurve, level, roofType, out curveArray);
 
           // if the roof is a curtain roof then set the mullions at the borders
           var nestedElements = speckleFootprintRoof.elements;