VMD-L Mailing List

From: Nicola De Mitri (nicola.demitri_at_sns.it)
Date: Thu Jan 23 2014 - 04:07:49 CST

Hi all,

I'm interested in rendering a '.cube' file in a particular fashion, that
I've only found referred to as "3D texture mapping" (cfr the 6th fig.
in this webpage: http://goo.gl/yWtgUQ). I think it is not implemented
in VMD but maybe it can be scripted or worked around.

As far as I understood, this kind of visualization highlights localized
areas of higher density, by rendering the cube in slices (the cut is
perpendicular to the line of sight) with both a color and a opacity
scale. By doing this, areas with a low density (or whatever) value
are essentially transparent, and the "Blobs" with higher values are
visible, although placed behind.

I've tried to fake this behavior by rendering several VolumeSlice at
increasing Z projections, using a White-to-black Color Scale and a
transparent material with angle-modulated trasparency; GLSL
renderer, all the lights off, white background.
However, white is still a "opaque" white, so the slices placed behind
are gradually less visible. Moreover, If my line of sight is along axes
X or Y, I don't perceive a box, but a grid of planes.

Have you ever tried to render a 3D texture mapping?
Do you know if an alpha channel is available for defining color scales?
Do you have any suggestion for a purposely written script?

Thanks in advance for your help,

Nicola