POV-Ray : Newsgroups : povray.general : Animation feature request. Server Time
22 Mar 2026 05:31:32 EDT (-0400)
  Animation feature request. (Message 1 to 5 of 5)  
From: m@b
Subject: Animation feature request.
Date: 20 Mar 2026 23:30:00
Message: <web.69be105f435354d91463fe62d568493a@news.povray.org>
I wish we had access to Subset_Start_Frame and Subset_End_Frame from within the
SDL.

We already have access to initial_frame, final_frame, frame_number, etc.

I have a inc file that reports (via #debug) animation average frame time,
estimated completion time, etc. It doesn't work if I am only rendering a subset
of an animation.

(In response to "Post something", Bald Eagle)

m@


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From: Maetes
Subject: Re: Animation feature request.
Date: 21 Mar 2026 08:40:00
Message: <web.69be907ff7a27764e29d7fa930225ff5@news.povray.org>
It won't solve your problem, but I want to advertise my animation script
collection again at this point.

https://www.maetes.com/en/povray-os/ma_screenplay


ma


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From: Bald Eagle
Subject: Re: Animation feature request.
Date: 21 Mar 2026 09:30:00
Message: <web.69be9c7bf7a277641f9dae3025979125@news.povray.org>
"m@b" <nomail@nomail> wrote:
> (In response to "Post something", Bald Eagle)

Thanks - that's one facet of this thread - so often we're independently trying
to work something out by ourselves (which is admirable), but the solution might
elude us for some time and thwart the completion of a project.

> I wish we had access to Subset_Start_Frame and Subset_End_Frame from within the
> SDL.
>
> We already have access to initial_frame, final_frame, frame_number, etc.
>
> I have a inc file that reports (via #debug) animation average frame time,
> estimated completion time, etc. It doesn't work if I am only rendering a subset
> of an animation.

Yes, that would be helpful.
I don't often use animation or ini files (that's more of a jr thing)
but I'm wondering if you can do something similar to what's done with screen.inc
where the user defines the camera position and look_at vectors as SDL-visible
identifiers, and then proceeds to use them from there.

I recall that you can set identifier values from an ini file, so perhaps you can
pass the information in to the main scene file that way.

3.2.5.1 Constant
Declare=IDENTIFIER=FLOAT Declares an identifier with a float value
You can now declare a constant in an INI file, and that constant will be
available to the scene. Since INI file statements may also be laced on the
command-line, you can therefore also declare on the command-line (though there
is no switch for it).

  Declare=MyValue=24
This would be the same as a #declare MyValue=24; in a scene file. The value on
the right-hand side must be a constant float value.

A possible use could be switching off radiosity or photons from command-line:

--in INI-file / on command-line

Declare=RAD=0

--in scenefile

global_settings {
  #if (RAD)
    radiosity {
    ...
    }
#end
}

So, in your ini file you do something like Subset_Start_Frame=30
but I'm wondering if you can then do something like
Declare=SSF=Subset_Start_Frame.
If not, you could just set Declare=SSF=30 and then do Subset_Start_Frame=SSF
(if that works)


- BE


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From: m@b
Subject: Re: Animation feature request.
Date: 22 Mar 2026 04:00:00
Message: <web.69bf9f70f7a277641463fe62d568493a@news.povray.org>
"Bald Eagle" <cre### [at] netscapenet> wrote:
> "m@b" <nomail@nomail> wrote:
> > (In response to "Post something", Bald Eagle)
>
> Thanks - that's one facet of this thread - so often we're independently trying
> to work something out by ourselves (which is admirable), but the solution might
> elude us for some time and thwart the completion of a project.
>
> > I wish we had access to Subset_Start_Frame and Subset_End_Frame from within the
> > SDL.
> >
> > We already have access to initial_frame, final_frame, frame_number, etc.
> >
> > I have a inc file that reports (via #debug) animation average frame time,
> > estimated completion time, etc. It doesn't work if I am only rendering a subset
> > of an animation.
>
> Yes, that would be helpful.
> I don't often use animation or ini files (that's more of a jr thing)
> but I'm wondering if you can do something similar to what's done with screen.inc
> where the user defines the camera position and look_at vectors as SDL-visible
> identifiers, and then proceeds to use them from there.
>
> I recall that you can set identifier values from an ini file, so perhaps you can
> pass the information in to the main scene file that way.
>
> 3.2.5.1 Constant
> Declare=IDENTIFIER=FLOAT Declares an identifier with a float value
> You can now declare a constant in an INI file, and that constant will be
> available to the scene. Since INI file statements may also be laced on the
> command-line, you can therefore also declare on the command-line (though there
> is no switch for it).
>
>   Declare=MyValue=24
> This would be the same as a #declare MyValue=24; in a scene file. The value on
> the right-hand side must be a constant float value.
>
> A possible use could be switching off radiosity or photons from command-line:
>
> --in INI-file / on command-line
>
> Declare=RAD=0
>
> --in scenefile
>
> global_settings {
>   #if (RAD)
>     radiosity {
>     ...
>     }
> #end
> }
>
> So, in your ini file you do something like Subset_Start_Frame=30
> but I'm wondering if you can then do something like
> Declare=SSF=Subset_Start_Frame.
> If not, you could just set Declare=SSF=30 and then do Subset_Start_Frame=SSF
> (if that works)
>
>
> - BE

Thanks for the reply, I didn't realise I could pass identifier values from an
ini file, that's useful.

Unfortunately "The value on the right-hand side must be a constant float value."

So this works:

   Subset_Start_Frame=394
   Declare=SSF=394

But these don't:

   Subset_Start_Frame=394
   Declare=SSF=Subset_Start_Frame

   Subset_Start_Frame=394
   Declare=SSF=float(Subset_Start_Frame)

   Declare=SSF=394
   Subset_Start_Frame=SSF

Declaring twice is no big hardship as long as I remember!
Thanks again,
m@


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From: jr
Subject: Re: Animation feature request.
Date: 22 Mar 2026 04:50:00
Message: <web.69bfad1af7a2776448bf72fa6cde94f1@news.povray.org>
hi,

"m@b" <nomail@nomail> wrote:
"Bald Eagle" <cre### [at] netscapenet> wrote:
> > ...
> > So, in your ini file you do something like Subset_Start_Frame=30
> > but I'm wondering if you can then do something like
> > Declare=SSF=Subset_Start_Frame.
> > If not, you could just set Declare=SSF=30 and then do Subset_Start_Frame=SSF
> > (if that works)
>
> Thanks for the reply, I didn't realise I could pass identifier values from an
> ini file, that's useful.
>
> Unfortunately "The value on the right-hand side must be a constant float value."
>
> So this works:
>
>    Subset_Start_Frame=394
>    Declare=SSF=394
>
> But these don't:
>
>    Subset_Start_Frame=394
>    Declare=SSF=Subset_Start_Frame
>
>    Subset_Start_Frame=394
>    Declare=SSF=float(Subset_Start_Frame)
>
>    Declare=SSF=394
>    Subset_Start_Frame=SSF
>
> Declaring twice is no big hardship as long as I remember!

another option, not yet mentioned, is having a (shell) script run from the
'pre_frame_command' which writes the values to a simple CSV type file that you
can read from within the scene.


regards, jr.


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