Thanks for the advice. You were right in that the background designator was
not the only thing defining the "background". The fog designator was the
problem, as it apparently put a black fog behind my molecule. Once I
removed it, I got a nice transparent background (original header below).
#include "colors.inc"
camera {
orthographic location <0,0,-60>
look_at <0,0,0>up <0,35.2678904747,0>right <36.5470367614,0,0>}
background { color rgb <0,0,0> }
light_source { <0.0,0.0,-600.0>color White}
fog { distance 100 colour rgb<0,0,0> }
Thanks,
Ray
On 6/1/07, James Stroud <[EMAIL PROTECTED]> wrote:
For povray, background is implicit (it exists as black if unspecified).
According to the docs "when the alpha channel is turned on, all areas of
the
image where the background is partly or fully visible will be partly or
fully
transparent". I haven't used ccp4mg, but it might be making a sphere or a
sky_sphere for the background instead of using the "background"
designator,
which could be causing problems. I suspect this is the case. Spheres are
not
transparent unless specified with an rgbt color_vector in the pigment
specifier. Setting 1.0 as the 4th term in the rgbt vector will give full
transparency. Also, some viewing programs do not display the alpha channel
and they will look non-transparent, but this is less likely than the
sphere
or sky_sphere scenarios.
If you post your pov files somewhere, I can give them a look. You will
probably not want to attach them if you post to the ccp4bb as they can be
quite big, but you can include them as attachments if you mail them
directly
to me ([EMAIL PROTECTED]).
James
On Friday 01 June 2007 10:54, Ray Bourdeau wrote:
> Hi all,
>
> I am generating images using ccp4mg (which is wonderful by the way), but
I
> can not figure out how to generate a povray input file that will yield
an
> image with a transparent background. Getting a transparent background
> using the screen snapshot works fine, but I would like to have a
rendered
> image. I have tried adding the +UA tag (which I believe should render
the
> alpha channel as transparent) as a povray command line option so that my
> input looks like such:
>
> povray +A +J0 +Q9 +UA +H2400 +W2400 input_file.pov
>
> Yet this still does not give me a transparent background. When
generating
> povray input files, does ccp4mg output the background as the alpha
channel
> or do I need to go about this a different way?
>
> Thanks,
>
> Ray
--
James Stroud
UCLA-DOE Institute for Genomics and Proteomics
Box 951570
Los Angeles, CA 90095
http://www.jamesstroud.com
--
Raymond W. Bourdeau
University of Chicago - Tang Lab
929 E 57th St. W423J
Chicago, IL 60637
tel: 773-702-4608
email: [EMAIL PROTECTED]
email: [EMAIL PROTECTED]
