ONE SIZE ALMOST FITS

Back in early August, I had the privilege of speaking at USC’s annual BIM Symposium on the topic of visual programming. This post is my attempt at a sort of editorial that follows the narrative of that talk. Along the way, I’ll include a few of the videos that I shared at the presentation which hopefully demonstrate the kind of tool creation I’m talking about. Hope you enjoy.

It’s been 5 years since we officially launched our research program at the Yazdani Studio of Cannon Design. During that period we’ve come to understand that the evolution of our process reflects the larger, changing relationship architects have with their means of production. We’ve always been a profession of hackers. Every building is a one-off made up of countless elegant hacks, each bringing disparate materials and systems together into a cohesive whole.  But when it comes to the software that designers have come to rely on, most of us have been content with enthusiastic consumerism, eagerly awaiting the next releases from software developers like Autodesk, McNeel and Bentley. In late 2007 something changed. McNeel introduced a visual programming plugin called Grasshopper authored by David Rutten, and more and more architects began to hack their tools as well as their buildings.

Using an Excel Spreadsheet to Control Revit Panels

The possibility of controlling panels in a Revit curtain wall through an Excel spreadsheet opens up a wide range of opportunities for interoperability between Revit and other tools in our workflow. Any program capable  of exporting a range of values could potentially send values directly to Revit, saving users the hours of manual data entry currently required to translate a design or analysis  model into a documentation (BIM) model.   To enable Revit to read in values from Excel , we looked at two Revit plugins; Revit Excel Link ,developed by Cad Technology Center and Whitefeet, written by Mario Guttman. Using a combination of Revit and both plugins, we were able to develop the workflow demonstrated in the video below.

Vasari Surface based on Solar Analysis

Project Vasari, a standalone application that expands on the Revit conceptual mass family interface (available here from Autodesk Labs) brings Ecotect analysis capabilities into the Revit environment.  We test drove this tool to see if we could create a surface that responds directly to the results of solar analysis. Vasari allows us to easily export analysis data in .CSV format, bring that information into Excel and read all the values generated from Solar Analysis. Having that numerical data available, we initially thought we could bring these values back into Revit to drive a specified parameter in the Pattern-based Curtain Panel family. Unfortunately, we discovered, that data exported from Vasari’s Solar Analysis does not always correspond with the position of curtain panels within the curtain wall. That is, data point 1, 2, 3… does not correspond to panel 1, 2, 3…etc.  In our experiments , the logic of how the .CSV data is organized has nothing to do with the row / column organization in a divided surface grid.  Without the help of a custom plugin that could perform automatic labeling of curtain panels based on position, using CSV data would require a user to manually enter a numerical value or label  panel by panel.

As a workaround, we used a tool that translates pixel color from an image into values that affect instance parameters within a Revit family.  By feeding in graphical results from Vasari’s Solar Analysis, we were able to achieve the desired effect.   This tool, known as the Bitmap to Panel plugin, can be downloaded from Zach Kron’s blog, Buildz: http://buildz.blogspot.com/2010/08/making-revit-forms-from-image-files-in.html . It works by translating grayscale image values int0 numerical data, which is then inserted into a specified parameter within the Revit curtain panel family.