Parametric Software review

Daniel Davis – 19 January 2010

A

nother question I frequently get is what software do I use &/ what software should someone learn. The following is a summary of parametric software you can use.

Graph based

When we talk about parametric software, we tend to think of graph based tools. The two major ones being Generative Components and Grasshopper. Both of these use a two dimensional relationship graph to express associations between geometry. Generative Components is the older of the two and as such is more frequently cited to in books and papers and projects. Grasshopper has the benefit of a more modern interface, making coding as fun as playing with lego. Generative Components is probably more powerful at the moment, but with the lead developer of GC – Robert Aish – off to Autodesk, I would expect Grasshopper to pull past GC.

Stack Based

Stack based tools store transformations to objects in a one dimensional stack. Changes can be made at any location in the stack and propagated through the remaining stack. The best known of these is 3dsMax. 3dsMax also has the ability to link values together through the Wire Parameter option, and these can even be wired to sliders. The Smart Filters in Photoshop also work as a parametric stack.

Associative history

Associative history is an editable record of how an object was created. Maya uses associative history enabling you to do things like create a loft from two curves and then go back and edit one of those curves, updating the loft. The major software in this space is CATIA/Digital Project, used on The Birds Nest, Sagrada Família and all of Frank Gehry’s buildings. A licence is prohibitively expensive preventing most people from using it.

CAD tools

Both Revit and Archicad have parametric tools. Revit allows the creation of Revit Families, which are driven from parameters. Walls can also be constrained in a manner similar to CATIA. And the new conceptual massing tool features associative history. Archicad works through the Geometric Description Language, which allows you to code parametric objects (sort of like Revit Families). It is a favorite argument of Revit Fanboys, and while unnatural it is surprisingly powerful.

Others

The spreadsheet, the first killer app of the personal computer, is parametric. Originally designed by Dan Bricklin, who while studying at the Harvard Business School observed: “As a professor was giving a lecture, he found an error in a single cell and was forced to change the value in every other cell.” The spreadsheet allows cells to be associated with each other through formula to allow the table to be quickly updated without manually reentering the data.

What you should learn

All of them. And make your own. Each program has a particular mode of translation, so locking yourself into one program limits what you can express. Knowing multiple programs expands this vocabulary. In terms of employment, since the software is changing so rapidly, it seems to me that learning how to learn software is more important than learning a specific piece of software.

7 February 2009 My servers crashed an lost the comments on this entry, so  feel free to comment again