[Chimera-users] POV-Ray setting for movie making

[Thomas Goddard]

Hi Paul,

   Eric Pettersen, another Chimera developer, I believe tested some 
different POV-ray settings, and Greg Couch has worked on that code a 
lot.  I don't really know anything about the POV-ray settings because I 
think I get better results without POV-ray as discussed by Elaine in a 
previous mailing list message.

http://www.cgl.ucsf.edu/pipermail/chimera-users/2009-June/004030.html

   I'm sending your POV-ray settings question to the mailing list and 
perhaps Eric or Greg will have suggestions.

	Tom





> Thanks Tom,
>
> The mpeg4 movie with qscale 1 looks pretty good. I forgot to mention in
> my first message that I was setting bitrate to 10000, and yet still the
> results were fuzzy around the edges. Seems like variable bitrate is the
> way to go.
>
> Can you give me any advice on antialias method, depth, threshold
> (currently I’m using recursive, 3, 0.3, respectively) or jitter (I’m
> using true with an amount of 1.0). I’ve read the chimera manual entries
> on the topics but I’m still confused, can’t see much difference when I
> change variables one at a time. Do you have favorite settings for these
> variables? Time to process, as long as it stays within a week for a 1600
> frame movie is fine, the product will go out as supplemental material
> for a paper, so I’m willing to wait if some change to the settings I’m
> using now will make a difference.
>
> Thanks a lot for your help!
>
> Paul
>
> ------------------------------------------------------------------------
>
> *From:* Tom Goddard [mailto:goddard at cgl.ucsf.edu]
> *Sent:* Wednesday, April 21, 2010 11:45 AM
> *To:* Paul Brandt
> *Cc:* chimera-users at cgl.ucsf.edu
> *Subject:* Re: [Chimera-users] POV-Ray setting for movie making
>
> Hi Paul,
>
> Sound very likely that the quality degradation is from the movie file
> compression. The movie compression algorithms use a perfect image every
> tens of frames and differences that are compressed between those frames
> I think. I suspect MPEG1 is one of the worst because it is the oldest
> format. You may see some improvement using the MPEG4 based codecs (mp4,
> avi, and mov movie command mformat values). The movie encode command two
> options that control compression are "bitrate" and "qscale". The bitrate
> option pertains to fixed bitrate compression schemes while qscale refers
> to variable bit rate (more modern) compression methods. In your old
> Chimera version I believe the default is bitrate 2000 Kbits/sec which
> gives pretty horrible quality but was chosen to improve the chances of
> PowerPoint being able to play the movie. Current Chimera daily builds
> instead use qscale 8 as the default which gives quite good quality but
> much bigger movie file size. If you really want the best possible
> quality and giant movie files is not a problem use qscale 1.
>
> http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/movie.html
>
> Tom
>
>
>
>
> Hello,
>
> I am using chimera alpha version 1.3 (build 2577) running in linux
> (sled11) to make a movie using POV-Ray.
>
> The quality of the first few frames is stunning but thereafter becomes
> fuzzy around the edges of the molecule. Is there a way to fix this so
> that the entire movie is as clear and nice as the first few frames? Is
> there something wrong with my settings? Is what I’m seeing an artifact
> of mpeg compression?
>
> I am using the following POV-Ray settings to make an Mpeg1 movie
>
> Quality 11
>
> Antialias: true
>
> Antialias method: recursive
>
> Antialias depth: 3
>
> Antialias threshold: 0.3
>
> Jitter: True
>
> Jitter amount: 1.0
>
> Transparent background: false
>
> Wait for POV-Ray to finish false
>
> Keep input files: false
>
> Thanks for the help!!
>
> Paul
>