Hi Jeff, Chimera supports a format for making geometric objects called BILD described in the Chimera manual: http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/bild.html Below is a 6 line BILD file that when opened in Chimera shows cylindrical arrows for the X (red), (green), and Z (blue) axes in the style of the program VMD. I made the axes 20 units long, with radius 1 and cone shaped tip with a radius of 2. Tom ----- File axes.bld: .color 1 0 0 .arrow 0 0 0 20 0 0 1 2 .color 0 1 0 .arrow 0 0 0 0 20 0 1 2 .color 0 0 1 .arrow 0 0 0 0 0 20 1 2

From: Jeff To: "'Thomas Goddard'" <goddard@cgl.ucsf.edu> Subject: RE: Chimera length units Date: Thu, 2 Nov 2006 17:30:29 -0800

i figured some of that but is good to hear it from the source.

one last question - if i want to make an origin with axes (like a CAD program might have) so i don't get lost after rotating my volumes a jillion times and have to click 'orient', is there a way for me to make a marker-based model (two markers for each axis) and put it slightly off-origin (like in the -,-,- octant) so that i have a visual on my axes as i rotate the scene?

as in, is there a simple way for me to hand-write a marker model that i can just load and fix to the scene?

thanks,

-jeff