VMD-L Mailing List

From: bsnmrem-obj_at_yahoo.com
Date: Thu May 31 2012 - 16:03:53 CDT

Dear Alex:

Here is the post I was referring to:

http://www.ks.uiuc.edu/Research/vmd/mailing_list/vmd-l/1820.html

I would like to draw many ellipsoids and be able to visualize
them. The result could be something just like this:

mol new
draw material Opaque
draw color 1
draw sphere {0.1 0.7 0.2} radius 0.3 resolution 100
draw color 2
draw sphere {1.0 2.0 1.0} radius 1.2 resolution 100
mol new
draw material Transparent
draw color 3
draw sphere {0.0 0.0 0.0} radius 1 resolution 100

Except that the spheres should be ellipsoids.

Each ellipsoid would be given by the length of its semi-principal
axes. Also, the ellipsoid could be translated and rotated. The
translation would be given by a three dimensional vector. The
rotation could be given either by a rotation matrix in three
dimensions or three angles, whichever is easier to work with.

Thank you for your attention.

----- Original Message -----
From: Axel Kohlmeyer <akohlmey_at_gmail.com>
To: "bsnmrem-obj_at_yahoo.com" <bsnmrem-obj_at_yahoo.com>
Cc: "vmd-l_at_ks.uiuc.edu" <vmd-l_at_ks.uiuc.edu>
Sent: Thursday, May 31, 2012 12:35 PM
Subject: Re: vmd-l: Drawing an ellipsoid

On Thu, May 31, 2012 at 9:44 AM, bsnmrem-obj_at_yahoo.com
<bsnmrem-obj_at_yahoo.com> wrote:
> Hi!
>
> I would like to draw an ellipsoid. I have read other posts about it and
> someone said that it could be done by scaling a sphere

"someone" is a horribly bad source of information.
almost as bad as the "friend of a friend".

> non-uniformly. However, I could not find out how to scale a sphere
> non-uniformly. Can someone please give me an example?

there is too little information here to give a reasonable answer.
what is it exactly that you want to do with that ellipsoid in VMD?

axel.

> Thanks,
> Brian
> 

-- 
Dr. Axel Kohlmeyer
akohlmey_at_gmail.com  http://goo.gl/1wk0
College of Science and Technology
Temple University, Philadelphia PA, USA.