From: Oleg Stroganov (
Date: Tue Aug 12 2008 - 18:03:29 CDT

Hello, John

Actually I've have done the following thing: I've saved vmd-representation
of the scene with amount of fog I need, then loaded this scene into
independent VMD session (with command line "vmd -e scene.vmd") and finally
typed "render Tachyon scene.dat" in VMD command prompt. My VMD session
("scene.vmd") contained these lines:

display depthcue on
display cuestart 0.500000
display cueend 10.000000
display cuedensity 0.450000
display cuemode Exp2

so, I guess depth cueing was enabled. Tachyon files which I've got in
normal mode ("vmd -e scene.vmd") and in display-free mode ("vmd -e
scene.vmd -dispdev none") were different - in latter there were no FOG at
all. Another interesting thing about the fog: I've tried to enable depth
cueing directly from command line, and this is what I've got in "dispdev
none" mode:

vmd > display depthcue on
vmd > display get depthcue
vmd >

I hope, this information will be useful,

Sincerely yours,

Oleg Stroganov

> Hi,
> You'll only see the "FOG" lines when depth cueing has been enabled
> in VMD. By default depth cueing is not enabled, so unless you have
> enabled it either by checking the Display->Depth Cueing option in the
> GUI, or by executing "display depthcue on", it will not be enabled
> in Tachyon renderings. Please double check and let me know if you're
> still having trouble.
> Cheers,
> John Stone
> On Fri, Aug 08, 2008 at 01:10:36AM +0400, Oleg Stroganov wrote:
>> Hello,
>> I've noticed that depth cueing settings are not saved during rendering
>> of
>> vmd scene with Tachyon renderer when vmd is launched in text mode
>> (-dispdev none is enabled in command line). When Tachyon dat-file is
>> saved
>> by VMD in normal mode, it contains the line like this:
>> but when VMD saves Tachyon dat-file in text mode this line is missing.
>> Is
>> this a bug? Is there any workaround?
>> Thank you.
>> Oleg Stroganov