From: John Stone (
Date: Mon Jan 27 2014 - 11:33:17 CST

  At present, the only type of background gradient that VMD supports is
a vertically oriented gradient. Yours is the first request I've had
for another type of background gradient. One complication with
implementing other types of gradients is that it should also be possible to
implement them with ray tracing engines such as Tachyon or POV-Ray.

I managed to implement ray tracing variants of the linear background gradient
we currently provide in a way that works even with mirror-reflective surfaces,
which eliminates surprises when using ray tracing to render high quality
images. It is not immediately clear to me if I could accomplish the
same thing for a radial background gradient. It might be doable
with a similar "sky sphere" approach, with the gradient being applied
as a distance from the polar axis of the sky sphere. I could try such
a scheme and see if it is workable, but it won't be something I can work
on for quite a while yet due to other demands on VMD development time.

In the short term, you can use Photoshop to achieve arbitrary gradient
backgrounds in your figures, with careful use of the various fill tools
and by choosing a solid background color that does not otherwise occur within
the rest of your image.

  John Stone

On Mon, Jan 27, 2014 at 11:08:58AM -0600, Fateme Sadat Emami wrote:
> Dear vmd users,
> Is it possible to set the background color gradient in a radial way
> (lighter/darker in the center and fading out towards the edges)?
> Best,
> Fatima
> ---------------------------------------------------
> Fateme Sadat Emami, Ph.D.
> Postdoctoral Fellow
> Non-Equilibrium Research Centre (NERC)
> Northwestern University
> 2145 Sheridan Road, Tech K231
> Evanston, IL 60208
> email:
> Web:

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