Monday, March 12, 2012


I'm happy to announce that I was wrong about not being able to split a twisted quad face into two triangles.  Matt Jezyk, (a renowned reviteer from way back) responded amazingly quickly to point out how this can be done.  It's very simple, but quite subtle.

You use the add edge command, then you have to hover over a vertex (corner), click on it and then do the same at the diagonally opposite corner.  Works like a charm, so you can start with an irregular extrusion, add diagonals to all the vertical sides, then push-pull it into shape.  Follow up with curtain system by face and you're in business. 

This confirms my previous experience that the conceptual massing approach to creating forms is much more powerful and flexible than it seems to be at first.  You really have to stick with it because there are so many hidden treasures.  Reminds me a bit of when I first started playing electric guitar.  So much power there, but really frustrating because you don't know how to control it.  That comes with hours & weeks & years of experience.  Ultimately, there's no substitute for putting in the time.

I just began to scratch the surface of what you can do with these techniques while messing around this evening.  You can deconstruct the shape by deleting edges or faces.  The result seems to depend on what part of the original extrusion the geometry you delete is descended from.  Was it a side or a lid ? Sometimes it collapses down to a different set of triangles. But sometimes you get back to a twisted quad surface.

Much to learn.  But right now I need to head home, so see you soon.


  1. Unfortunately, you can't add an edge on the top or bottom of an extrusion. Only on the vertical edges as you pointed out which is a huge limitation. Once a vertical quad is triangulated, you can't ad a second edge to split to face in two triangles. These are the reason why we still use SketchUp, Rhino on these types of projects.

  2. Thanks Rick

    I used to use sketchup a lot, and it's a great little tool. It would be nice to have the best of both worlds, but in reality we have to make choices. My view is that there is a lot of "hidden potential" in the Revit/Vasari approach to modelling, so it's worth persevering beyond the initial frustrations.

    Do you know of an easy way to convert Sketchup surfaces into a solid so that we could put it in a massing family and create floors ?

  3. Truly humbled looking thru your site today. Incredible work.


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