Revision help: which views show this object?

[duncan.lithgow]

The wonderful thing about working in 3d is that every view is just a view of the same database. The horrible thing about delivering drawings from a 3d model is that every view is just a view of the same database. So when there is a revision to already issued drawings how do I find all the views that need revision clouds? ...

Does anyone know of a way in the API to find all views showing an object with a given ID number? I'm thinking a first sweep maybe comparing views on sheets and their depths to object geometri, then a second sweep checking visability against views with view templates, and a third checking for view specific overrides. Otherwise this kind of thing would take forever.

Ideas anyone? I'd like to add this to my list of API projects ...

[jeremytammik]

Dear Duncan,

This might be a lot simpler than you think.

One overload of the FlteredElementCollector constructor takes a view element id as an input argument and returns all visible elements in that view.

You could therefore simply cycle through all views, instantiate a view-specific element collector for each, and check whether the elements it returns include your target element.

Best regards,

Jeremy

[duncan.lithgow]

Hi Jeremy

Great news. I thought someone would know how to do this. I'll see if we can convince someone to implement this functionality (my coding skills are still pretty hopeless.)

Duncan

[jeremytammik]

Hi Duncan,

Please provide a sample model and an exact description of the required input, user interaction and output.

That will enable interested parties to take a look at it.

Thank you.

Cheers, 

Jeremy

[Anonymous]

The solution as Jeremy suggested is certainly possible, BUT in a model with many views, it can take an extremely long time to run.

The reason for this is, (as far as I can tell), when using a view-specific FilteredElementCollector, Revit effectively opens that view and checks whether the element is visible in the view.  

The result of this is that getting a list of views where an element is present takes the same amount of time as opening every view that is checked.

That being said, here is the code that I have for this:

public static IEnumerable<View> FindAllViewsWhereAllElementsVisible(this IList<Element> elements)
        {
            if (elements == null) throw new ArgumentNullException("elements");
 
            if (elements.Count == 0) return new List<View>();
 
            Document doc = elements.First().Document;
 
            IEnumerable<View> relevantViewList = doc.FindAllViewsThatCanDisplayElements();
 
            List<ElementId> idsToCheck = (from el in elements select el.Id).ToList();
 
            return (from v in relevantViewList
                    let idList =
                        new FilteredElementCollector(doc, v.Id)
                        .WhereElementIsNotElementType().ToElementIds()
                    where !idsToCheck.Except(idList).Any()
                    select v);
        }

 Helper function:

public static IEnumerable<View> FindAllViewsThatCanDisplayElements(this Document doc)
        {
            ElementMulticlassFilter filter =
                new ElementMulticlassFilter(new List<Type> { typeof(View3D), typeof(ViewPlan), typeof(ViewSection) });

            return new FilteredElementCollector(doc).WherePasses(filter).Cast<View>().Where(v => !v.IsTemplate);
        }

If you can't tell, I'm a big fan of LINQ... Let me know if you need me to explain anything that's happening here.

Colin

[jeremytammik]

Hi Colin,

Thank you for the very nice enhancement!

I like it!

You also seem to like extension methods, performance optimisation and the ElementMulticlassFilter.

So do I.

I therefore integrated your code into The Building Coder samples and implemented a new external command CmdViewsShowingElements to exercise it:

http://thebuildingcoder.typepad.com/blog/2014/05/views-displaying-given-element-svg-and-nosql.html#6

Cheers,

Jeremy