Automating Element Cutting in Revit

Hi there!

Welcome to the first ever issue of Showcase Fridays! This weekly series will take you on a tour of Scripository's resources, diving deeper on how some of these resources work.

While these emails will often get quite technical (assuming familiarity with tools like Grasshopper and Dynamo), I'll keep the explanations as clear and as approachable as I can.

Automating Element Cutting in Revit

It’s pretty simple to cut things in Revit, all you have to do is select two elements and use the “cut” button. The issue is that you can only cut two elements at a time. This means if you have 50 elements to cut, you have to go through each element one by one, clicking, waiting, clicking again…

That’s where cut elements (grasshopper) and cut elements (dynamo) in Scripsitory plays a part. Instead of doing this manually, the script loops through all the selected elements and then tries to cut them. And surprisingly, it's a very simple process. It’s actually just a simple function in the Revit API that does exactly what we need:

public static void AddInstanceVoidCut(
    Document document,
    Element element,
    Element cuttingInstance
)

If you’ve noticed, the function does exactly what the manual interface does. Feed it two elements, and it handles the cutting. All the script is doing then, is looping through the list of elements while running this function each time.

It's so simple that it's surprising Revit doesn't have a built-in command for this. They’re two versions of the script because while Dynamo is easier to distribute, I needed the cutting functionality in some RhinoInside Revit scripts too.

Until next Friday!

Best regards,

Braden