fix(Revit): DirectShape Instances to Speckle Conversion support (#3572)

For POC purposes - implements a fix - needs investigation

Objects/Converters/ConverterRevit/ConverterRevitShared/PartialClasses/ConvertDirectShape.cs

@@ -240,25 +240,35 @@ public ApplicationObject DirectShapeToNative(DirectShape speckleDs, ToNativeMesh
     return appObj;
   }
 
-  private DirectShape DirectShapeToSpeckle(DB.DirectShape revitAc)
+  private void ProcessGeometry(IEnumerable<GeometryObject> geometryObjects, Document revitDoc, List<Base> geometries)
   {
-    var cat = ((BuiltInCategory)revitAc.Category.Id.IntegerValue).ToString();
-    var category = Categories.GetSchemaBuilderCategoryFromBuiltIn(cat);
-    var element = revitAc.get_Geometry(new Options());
-
-    var geometries = new List<Base>();
-    foreach (var obj in element)
+    foreach (var obj in geometryObjects)
     {
       switch (obj)
       {
         case DB.Mesh mesh:
-          geometries.Add(MeshToSpeckle(mesh, revitAc.Document));
+          geometries.Add(MeshToSpeckle(mesh, revitDoc));
           break;
         case Solid solid: // TODO Should be replaced with 'BrepToSpeckle' when it works.
-          geometries.AddRange(ConvertSolidsByRenderMaterial(new[] { solid }, revitAc.Document));
+          geometries.AddRange(ConvertSolidsByRenderMaterial(new[] { solid }, revitDoc));
+          break;
+        case GeometryInstance gi:
+          var instanceGeometryElement = gi.GetSymbolGeometry(gi.Transform);
+          ProcessGeometry(instanceGeometryElement, revitDoc, geometries);
           break;
       }
     }
+  }
+
+  private DirectShape DirectShapeToSpeckle(DB.DirectShape revitAc)
+  {
+    var cat = ((BuiltInCategory)revitAc.Category.Id.IntegerValue).ToString();
+    var category = Categories.GetSchemaBuilderCategoryFromBuiltIn(cat);
+    var element = revitAc.get_Geometry(new Options());
+
+    var geometries = new List<Base>();
+
+    ProcessGeometry(element, revitAc.Document, geometries);
 
     var speckleAc = new DirectShape(revitAc.Name, category, geometries);