Looking for figure of part of an A2 affine building Somewhere, I  don't remember where, I saw a beautiful 3D figure of part a CAT(0) simplicial complex.  I am thinking and hoping that this was some finite piece of an affine building of type A2, presumably in characteristic 2.  But I'm very frustrated now that I just can't remember exactly what I saw or where I saw it.  It was something like part of the neighborhood of radius 1 or radius 2 of a vertex, with enough simplices removed so that the rest fits in $\mathbb{R}^3$.  It looked like Mathematica graphics, since (in my recollection) it had good colors to help show the 3-dimensional structure.  I'm thinking that I saw it in the AMS Notices, but it could also have been in an AMS calendar or elsewhere.  Does anyone remember seeing an image like this, and if so, where?
I'm asking because I'd like to have such an image in a paper that I'm working on, not necessarily the one that I saw but something similar.

I got some good answers to my question, both here and in private e-mail to Bill Casselman.  But in the end I decided to make my own diagram (with the aid of TikZ and Python SAGE).  Here it is.
alt text http://www.freeimagehosting.net/uploads/e38638d43e.png

For those who are interested in the TikZ and SAGE code, I combined them into one TeX document.  I posted both the TeX source and its PDF output (from pdflatex) on my web page.
 A: Check out http://dean.clas.uconn.edu/teitelbaum/colorout.gif
I made this image long ago for the cover of the AMS Notices.
See http://www.ams.org/notices/199510/teitelbaum.pdf
A: A picture similar to the one you've made can be found in Garrett's book on Buildings and classical groups.
http://www.amazon.com/Buildings-classical-groups-Paul-Garrett/dp/041206331X
A: This may not be precisely what you ask for, but my colleague Paul Gunnells wrote a nice article for the May 2006 AMS Notices with some color pictures involving Kazhdan-Lusztig cells in small rank Coxeter groups.   The link is http://www.ams.org/notices/200605/fea-gunnells.pdf
I have had some conversations with him about cells and have gotten some insight from the pictures he generated using graphics software (which probably wasn't Mathematica but also doesn't run on his current computing hardware).    This has just been a sporadic interest of his, though he has an ongoing collaboration with Belolipetsky mostly involving cells in Coxeter groups which are not finite or affine.
Of course this kind of Coxeter group information is only one part of the building construction, but a crucial one to visualize.
ADDED: To follow up Greg's comment, there have been other items in the Notices dealing directly with Bruhat-Tits buildings.   An article by K.S. Brown in the November 2002 issue has a nice $A_3$ picture: http://www.ams.org/notices/200210/what-is.pdf
(Most such articles and graphics have been influenced by the editorial work of Bill Casselman at UBC, who would be the best source of technical information.)
