VMD-L Mailing List

From: Pacci Evaristo, Felipe Fabricio (felipepacci_at_gmail.com)
Date: Tue Mar 02 2021 - 15:52:59 CST

Hi everyone,

Thank you so very much for your prompt responses! It turns out I was indeed
missing something really obvious - I was unaware .tga files didn't support
the alpha channel! It all works out great rendering .pov files into .pgn!
Thanks again!

All the best,

*Felipe Fabricio Pacci Evaristo*
*Mobile:* +1(773)569-2978
*Email:* felipepacci_at_gmail.com
*Skype:* felipepacci

On Tue, Mar 2, 2021 at 4:40 PM John Stone <johns_at_ks.uiuc.edu> wrote:

> Hi,
> Josh is correct that a very critical issue for getting so-called
> "transparent backgrounds" is choosing an image file format that supports
> an "alpha channel". To get the desired outcome, both the rendering engine
> and the image file format have to fully support alpha channel output.
>
> POV-Ray and the NVIDIA OptiX GPU-based version of Tachyon implement this
> feature in the renderer, and both of them support output to PNG files.
>
> At present, the CPU version of Tachyon doesn't yet implement alpha channel
> output mode as I just haven't had time to rewrite the affected parts
> of the code to add it yet. It was comparatively easy to add to the GPU
> version of the code without affecting performance.
>
> Best,
> John
>
> On Tue, Mar 02, 2021 at 09:17:59PM +0000, Vermaas, Josh wrote:
> > Hi Felipe,
> >
> >
> >
> > .tga files can't do transparency. .png files can though, and it looks
> like
> > POV-Ray is being told to write a .png based on your command, so I
> don't
> > know what's up, since you also have the +ua argument folks say is
> > essential:
> > [1]
> https://urldefense.com/v3/__http://news.povray.org/povray.general/thread/*3C59dbba2b*40news.povray.org*3E/__;JSUl!!DZ3fjg!pwxBUvTNZ4dskRr580nkP12pIjp65tKqq6H2FN0eLQbhAhwFBvOXRJddJtpp9of8Fw$
> >
> >
> >
> > For my own rendering purposes, I use OptiX, with the options John
> laid out
> > here:
> > [2]https://www.ks.uiuc.edu/Research/vmd/mailing_list/vmd-l/31053.html
> >
> >
> >
> > -Josh
> >
> >
> >
> > From: <owner-vmd-l_at_ks.uiuc.edu> on behalf of "Pacci Evaristo, Felipe
> > Fabricio" <felipepacci_at_gmail.com>
> > Date: Tuesday, March 2, 2021 at 3:18 PM
> > To: "vmd-l_at_ks.uiuc.edu" <vmd-l_at_ks.uiuc.edu>
> > Subject: vmd-l: Render image background-free
> >
> >
> >
> > Hi there,
> >
> >
> >
> > I've been trying to solve this problem for a while now. I'm on macOS
> > Catalina. I've been trying to render an image background-free on VMD.
> I've
> > been trying to use POV-Ray for that. I found tutorials where people
> have
> > used the following line in the Render Command box in the GUI interface
> > (except for the link to the POV-Ray executable):
> >
> >
> >
> >
> '/Users/felipepacci/Downloads/PovrayCommandLineMacV2//Povray37UnofficialMacCmd'
> > +W%w +H%h -I%s -O%s.png +D +X +A +FN +UA -res 1600 900
> >
> >
> >
> > This render does produce a .pov file; however, when I try to render it
> > into a .tga file in POV-Ray, the output .tga image still contains a
> > background. Am I missing something really obvious here?
> >
> >
> >
> > I'm open to other methods that don't include POV-Ray to generate my
> > background-free image.
> >
> >
> >
> > Thank you beforehand for any help provided,
> >
> >
> >
> > Felipe Fabricio Pacci Evaristo
> >
> > Mobile: +1(773)569-2978
> >
> > Email: [3]felipepacci_at_gmail.com
> >
> > Skype: felipepacci
> >
> > References
> >
> > Visible links
> > 1.
> https://urldefense.com/v3/__http://news.povray.org/povray.general/thread/*3C59dbba2b*40news.povray.org*3E/__;JSUl!!DZ3fjg!sXtoTZWxyVOoJFd6yhSYMYD5WGQ5FlFdp19IBsiFoenHmvXykCSgQMAX7NQdqZc1eQ$
> > 2. https://www.ks.uiuc.edu/Research/vmd/mailing_list/vmd-l/31053.html
> > 3. mailto:felipepacci_at_gmail.com
>
> --
> NIH Center for Macromolecular Modeling and Bioinformatics
> Beckman Institute for Advanced Science and Technology
> University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
> http://www.ks.uiuc.edu/~johns/ Phone: 217-244-3349
> http://www.ks.uiuc.edu/Research/vmd/
>