I'm actually using povray 3.1 but perhaps this applies to the new beta too.

The documentation for "Field Rendering" says that line numbering in pov
starts from 0 and that by default it outputs an EVEN field first. This
suggests that in the first output file out001.tga it is the TOP line and
following alternate lines which contain the useful data, with the other
lines beneath being duplicates.

However using povray 3.1 it seems that my out001.tga file has the
line-below-the-top which contains the useful data, and the line immediately
below is a duplicate. This looks like the ODD field is first (if you count
line numbers from 0).

Is this a bug? And does the beta behave like this?

Colin

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In article <3cd6e6d7@news.povray.org> , "PovRAY" <cbd### [at] my-dejacom> wrote:

> I'm actually using povray 3.1 but perhaps this applies to the new beta too.
>
> The documentation for "Field Rendering" says that line numbering in pov
> starts from 0 and that by default it outputs an EVEN field first. This
> suggests that in the first output file out001.tga it is the TOP line and
> following alternate lines which contain the useful data, with the other
> lines beneath being duplicates.
>
> However using povray 3.1 it seems that my out001.tga file has the
> line-below-the-top which contains the useful data, and the line immediately
> below is a duplicate. This looks like the ODD field is first (if you count
> line numbers from 0).
>
> Is this a bug? And does the beta behave like this?

Line numbering in POV-Ray starts from zero for historic and compter graphic
standard reasons.  However, as in hardware (and any non-CS use) counting
starts from one, lines are of course counted from one in this respect...

    Thorsten

____________________________________________________
Thorsten Froehlich
e-mail: mac### [at] povrayorg

I am a member of the POV-Ray Team.
Visit POV-Ray on the web: http://mac.povray.org

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Yes, but the User guide says explicitly:

"The even scan lines make up the even field, and are drawn first (i.e. scan
lines 0, 2, 4, etc.)"

and

"By default, the first frame [rendered] is the even field"

But if you examine the first output file of the animation, it is line 1,3,5
etc (odd field) which contains the calculated pixels, with the lines beneath
(even) field being duplicates. This is the
opposite of what the user guide says.

Perhaps that section of the user guide should say that for the purpose of
the command line switches lines should be counted from 1, but this would
just confuse matters further.

I think that the Field Rendering subsection in the User Guide could do with
re-writing to correct the odd or even field first inconsistency and also to
describe how the lines are written into the output files.

Colin


"Thorsten Froehlich" <tho### [at] trfde> wrote in message
news:3cd6fc72@news.povray.org...
> In article <3cd6e6d7@news.povray.org> , "PovRAY" <cbd### [at] my-dejacom>
wrote:
>
> > I'm actually using povray 3.1 but perhaps this applies to the new beta
too.
> >
> > The documentation for "Field Rendering" says that line numbering in pov
> > starts from 0 and that by default it outputs an EVEN field first. This
> > suggests that in the first output file out001.tga it is the TOP line and
> > following alternate lines which contain the useful data, with the other
> > lines beneath being duplicates.
> >
> > However using povray 3.1 it seems that my out001.tga file has the
> > line-below-the-top which contains the useful data, and the line
immediately
> > below is a duplicate. This looks like the ODD field is first (if you
count
> > line numbers from 0).
> >
> > Is this a bug? And does the beta behave like this?
>
> Line numbering in POV-Ray starts from zero for historic and compter
graphic
> standard reasons.  However, as in hardware (and any non-CS use) counting
> starts from one, lines are of course counted from one in this respect...
>
>     Thorsten
>
> ____________________________________________________
> Thorsten Froehlich
> e-mail: mac### [at] povrayorg
>
> I am a member of the POV-Ray Team.
> Visit POV-Ray on the web: http://mac.povray.org

Post a reply to this message