Sunday, December 4, 2011

“Shifting planes always implicitize a surface of revolution”

...Is a slightly weird title of an article*.
I’ve borrowed it because of relevance to my topic, today. First, I really liked the way it connects ‘shifting planes’ with the idea of a revolution brewing under the surface. Then, I got intrigued by the word ‘implicitize’, fully convinced such word did not exist (and the MS spell-checker was with me on this one), so I looked it up and it DOES one thing led to another and...

Actually, the original question I was going to put up was:
Why do planes (floors) shift away from their original locations when exported out of Revit as IFC 2x3 files and imported into 3 different applications?
I wrote on ‘twisting columns’ recently and received some assistance in principle.
These shifting planes are even more interesting then the twisting columns, for two reasons:
ONE: floors are supposed to be ‘system families’ in Revit, I’d expect them to behave more predictably then hosted ones (what I believe columns were);
TWO: the same issue occurred on three very different projects, created by three very different companies over a six month time span.
... but then, do not worry too much. It all got fixed up.

The helpful chap at the tech-support located the patch I needed and following the download/installation, the planes no longer shift from their places.
Sleep easy.

* Shifting planes always implicitize a surface of revolution
Author:  Eng-Wee Chionh  School of Computing, National University of Singapore, Singapore 117590 
Published in:
· Journal
Computer Aided Geometric Design archive 
Volume 26 Issue 4, May, 2009
Elsevier Science Publishers B. V. Amsterdam, The Netherlands, The Netherlands