December 2008 I walked out of AU with two goals in mind:
1) To learn Revit, because I'd never used it.
2) To use Revit to build a Stadium Sightline Design Tool.
I flew back to Thailand and, settling into what became a year-long break, got down to business...13 months, 2 trips back to the US, 2 computers, 2 releases of Revit, and 4 South East Asian cities later, this is what I came up with.
Part 1: The Grid
Understanding the principles of seating bowl grid geometry is one thing, programming a grid family is a much tougher nut to crack...but i figured it out.
Part 2: The Section
3 decades ago (1997, actually) I learned about C-values, Focal Distances and all that. Putting it together here though required both digging into trig fundamentals and entering a list of parameters as long as my arm.
The Sightline Design Family I developed uses the key variables: C-Value, Distance to First Spectator, Eye Height, Row Width. I also threw in a parameter for Minimum Incremental Distance Between Treads, essentially a rounding factor, which can positively impact construction efficiency.
Creating a section in 3D allowed me to project a preliminary seat count for each structural bay. I have different tool for counting seats more definitively as the design progresses.
Though I only show the seating section as a single mass here, I also have a version which will itemize and schedule each individual piece of precast. This could be a useful tool for quantity surveys in the later stages of the design.
Part 3: The Bowl
Here I bring both tools together. The model shown took me about 10 minutes to assemble. By linking my sightline section family to the grid, I can cycle through endless bowl options.
There is surely more to investigate; vomitories, disabled platforms, rails and such...Right now, my priority is to look at a method which imports x,y,z points from an Excel spreadsheet. That might make things a bit easier because these families do get a bit heavy.
I owe 2 debts of extreme gratitude to a pair of guys who don't even know I exist.
First is David Baldacchino. I took his class on Fuzzy Math Essentials at AU in 2008. I didn't know anything about Revit Families when I walked in, but knew I would be able to tackle this project when I walked out. I kept the class handout and referenced it often. His blog is here: http://do-u-revit.blogspot.com/
The other is the Revit Family Man. I don't know what became of him because his site has gone a little quiet, but I reviewed his page about Revit Formulae almost every time I sat down: http://revitfamilies.blogspot.com/2005/10/revit-formulae.html
I'd love feedback from others who have been looking at stadium design Revit. I think there is a lot more to be explored, and its fun too!