Tuesday, January 11, 2011

Complex Rigging and Built Up Forms pt.1

I just love talking with people at AU who want to give me their sob story about some young hot-rod architecture intern who came in and made a bunch of great forms in Rhino, and then sent them into 3dMAX and morphed them, and now they need to recreate these forms in Revit and can't figure out how to do it and waahh waahh...U CAN"T DO THAT IN REVIT.

There's certainly a deeper question of 'Why haven't the tools in the conceptual massing editor been picked up by students' but that's way far beyond the scope of my blog.  What i am interested in is seeing how far I can push form generation with the tools i have.

There is a fellow i work with.  Very talented young man.  He is working in Digital Projects.  And just from looking over his shoulder occasionally, i see his process involves a lot of stacking and interlinking of parametric elements.  Its like a pyramid that slowly builds upwards.  It doesn't seem too different from how i think about form generation in Revit.

With that in mind, I wanted to start looking at how I could build some interesting forms by creating more complex rigs, and then building upon them.

I want to start here:

Ambitious?  Maybe.  However, I am not interested in recreating the Bird's Nest.  Hell no....though it is a very compelling form, one of these white elephants is enough....I am after the underlying geometry that makes this form possible...which is an oval shaped cone with a saddle shaped top...or at least that's where the affair starts!

So where to begin?  How about a pair of ovals like these.  I'll link the dimensions of the top oval to the bottom by sticking in a variable to control the incline angle.

To get the saddle shape at the top, I'll have to generate a void form to cut the initial oval-cone.  It won't quite be a toroid, but the cutting surface will come close.  First i have to develop a curve for the void form to sweep along.

The lengths of this curve are linked to the dimensions of the oval-cone.

Next I'll generate the void form using a bunch of dimensioned reference points placed at the ends of my sweeping curve.

And then i have 2 masses that look like this

change the cutting mass to a void, add an oval to cut a hole in the middle and bang!

With a little adjusting of the parameters, it gets pretty close to the basic mass of the bird's nest.

This is the list of the parameters:

This is the mass file:


This ought to be fun to play with until the NDA on the new release expires...


  1. And yet another very nice blog from you :)

    Although it is not the main focus from this blog entry, i do want to hook into the part where you ask yourself: 'Why haven't the tools in the conceptual massing editor been picked up by students'
    and i realize that we too, don’t use the massing very much, only in rare occasions. in my opinion it is because of the idea that conceptual massing is not accurate. in our business where we make concrete structures that have to be cm accurate (and preferred to have mm accuracy) something as conceptual massing does not really cross the mind.
    Although i must admit, strange enough the conceptual massing seems to offer way more freedom in family creation that normal families in revit.
    So I keep wondering, how accurate CAN conceptual massing be ? or is it just “fun” for the architectural business where there is more random dragging and dropping the shapehandles till you see something that looks ok ?

  2. I think you are missing the point slightly. The biggest problem that I think most people face is how to put real Revit elements, Structural beams and columns for example, to your freeformed shape It doesn't matter whether it was modeled in Rhino, Max or the conceptual massing environment. The tools in the Real Revit modeling environment are lacking seriously. Look at the brace tool you have a very minimal control over how the brace attaches an element.

  3. Why don't you post that as a solution to this challenge on DesignBymany http://designbymany.com/content/modeling-bejjing-national-stadium

    Great Post!


  4. Hire more students from Boston. Closer to the tree, apples etc.