From: Töre Han Balta (torehanb_at_gmail.com)
Date: Sun Dec 11 2011 - 18:24:40 CST

2011/12/12 Töre Han Balta <torehanb_at_gmail.com>

>
> This is it!
>
>> no, this is a user error.
>>
>> you have multiple representations of the
>> same type for the same atoms with *exactly*
>> the same size options. with OpenGL the latter
>> representations show up "on top" due to the
>> way OpenGL is implemented, but effectively
>> you are depending on undefined behavior.
>> raytracing software handles these cases
>> differently, so you get a different output.
>>
>> to get what you want, you just have to remove
>> the ambiguity, e.g. by setting the "Sphere Scale"
>> and "Bond Scale" parameters in the first representation
>> to something smaller than what you using in the
>> second and third, or enlarge the radii in the latter two.
>>
>> this is neither a bug in VMD nor in any driver.
>> the data is all there and being processed.
>>
>
>

> Thanks for a detailed description Dr. Axel.
>
>
> 2011/12/12 Axel Kohlmeyer <akohlmey_at_gmail.com>
>
>> On Sun, Dec 11, 2011 at 6:56 PM, Töre Han Balta <torehanb_at_gmail.com>
>> wrote:
>> > Hi,
>> >
>> > I'm using vmd-1.9 on a 64bit Fedora distribution of linux.
>> >
>> > Here is "uname -a "Linux localhost.localdomain 2.6.41.1-1.fc15.x86_64
>> #1 SMP
>> > Fri Nov 11 21:36:28 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
>> >
>> > I've attached is the vmd script and pdb file that I'm trying to take
>> > snapshot of the screen.
>> >
>> > I have also attached images ans images named as to have correspondence
>> with
>> > the render method. I converted images to jpg to reduce size.
>> >
>> > In the *.vmd file, there are three representation of the molecule with
>> > different coloring options.
>> > I am trying to render the screen image, but tachyon methods just renders
>> > image as if there is no representation except the first one.
>>
>> thanks. this is a pretty complete description.
>>
>> > Could it be a GPU driver problem?
>>
>> no, this is a user error.
>>
>> you have multiple representations of the
>> same type for the same atoms with *exactly*
>> the same size options. with OpenGL the latter
>> representations show up "on top" due to the
>> way OpenGL is implemented, but effectively
>> you are depending on undefined behavior.
>> raytracing software handles these cases
>> differently, so you get a different output.
>>
>> to get what you want, you just have to remove
>> the ambiguity, e.g. by setting the "Sphere Scale"
>> and "Bond Scale" parameters in the first representation
>> to something smaller than what you using in the
>> second and third, or enlarge the radii in the latter two.
>>
>> this is neither a bug in VMD nor in any driver.
>> the data is all there and being processed.
>>
>> cheers,
>> axel.
>> >
>> >
>>
>> --
>> Dr. Axel Kohlmeyer
>> akohlmey_at_gmail.com http://goo.gl/1wk0
>>
>> College of Science and Technology
>> Temple University, Philadelphia PA, USA.
>>
>
>