Clean up your desktop! Sit up straight! Hide the unmentionables! We have a guest!
Joe Kendsersky works at Autodesk as a Customer Success Engineer for Revit Architecture. He's like an ADSK Green Beret who gets parachuted into customer offices to smooth over the bumps on their road to BIM victory. He is trained as an architect and joined Revit Technology in 2000, and subsequently Autodesk in 2002. Joe is a wealth of information about what it going on in offices as well as what is being developed in the factory. Today, dear readers, he is going to share some tips and tricks from a project that is close to my heart and 15' from my desk. Without further ado, take it away Joe!
[Applause]
Making the "Boomerang" Ceiling
The conceptual modeling environment allows users to design and analyze forms and also create parametric sub components that are intelligent and adapt to the form. However, in cases where you may need to use an existing family as a sub component, the new massing environment allows users to nest existing families into a Curtain Panel Pattern Based template.
The example we'll go through is from a project that I worked on - The Autodesk Customer Briefing Centers ceiling "boomerang" element in Waltham MA, designed by KlingStubbins, Cambridge MA. It was a study given to me by our Revit QA team while exploring the new modeling tools for RAC 2010.
Below is an image of the component and hexagon pattern. When assembled, the repeating ceiling shape creates an undulating convex / concave form.

The challenge was how to begin modeling the component, what template to start off with, how to break down the entire assembly into a kit of parts. For the component, I started with the Curtain Panel Pattern Based template hexagon tile pattern, but realized that its sides are not equilateral – as shown in the image below by superimposing a sketched hexagon over the hexagon tile pattern in the template. Working in this tile pattern was not going to work because it was not a true hexagon and also it would have been very difficult to model several elements within the same context. So, I decided to try and build the geometry with a triangular tile pattern instead. The thought behind it is to break down element further to a more granular level – a single boomerang component.
Attempt made with hexagon pattern:
Attempt made with triangular pattern:

As we can see, I was getting close but encountered several modeling challenges with the creation of the component. But then, I had the idea of reusing the existing generic model family and loading it into the Curtain Panel Pattern Based template with a triangular tile pattern, and it worked.
Here is the process:
The ceiling component is a generic model family created using a solid extrusion and void revolve to create the concave shape.

Open the Curtain Panel Pattern Based template and switch the pattern to triangular checkerboard – this is the same shape / pattern as the ceiling component. Also, this pattern will allow us to have two coinciding surfaces to create the overlap in the hexagon design. When assembled, three components are positioned up (concave) and another three are positioned down (convex) to form the hexagon shape.
Adjust the horizontal and vertical spacing of the parameters – set values that are close to the actual size of the component that will be inserted.
Insert the existing family into the Curtain Panel Pattern Based template on level 1 and move / align it into position with triangular tile pattern. Given the generic family has some symbolic lines sketched in plan makes it easier for you to align with the triangular pattern.

Load and test the component in the massing environment to reconcile any problems – I prefer toggling views so you can view the curtain panel pattern family and massing side by side, this allows you to easily work / test back and forth.
In the massing environment – after creating the form, dividing the surface and placing the component – you’ll need to adjust the surfaces grid rotation, flip or mirror, indent values and set U V spacing values to match with the component actual size, position.
Before adjusting surfaces grid rotation, U V instance parameters:
After adjusting surfaces grid rotation, U V instance parameters:
Since the ceiling component undulates, you’ll have to overlap two surfaces. This can be done by copying one surface (using 0’ value) and then by adjusting the surfaces instance parameters (mirror, rotate and indent) so the surface components complement one another to form the concave-convex hexagon pattern.
This exercise was a group collaboration with several colleagues. I would like to thank Zach Kron, Heather Lech, Lira Nikolovska, Matthew Jezyk, Greg Demchak for the challenge and working with me through the process.
If you have any questions regarding this exercise, please contact:
Joe Kendsersky
josef.kendsersky@autodesk.com