Here is a version where I've increased the contrast in post:

http://individual.utoronto.ca/edegiuli/mediaproblem2.jpg

There should be smooth transitions everywhere, but you can see there are
places where the colour changes very sharply.  Moreover, you can see that
there are places where a dark part is inside a lighter spot, which indicates
the the interior region has been clipped and set back to dark colour.  In
1D:

http://individual.utoronto.ca/edegiuli/clipping.jpg

Like I said, my data is scaled between 0 and 0.99, so it looks like it is
being clipped as the density is integrated over a ray through the media.

Eric

"Christopher James Huff" <cja### [at] earthlinknet> wrote in message
news:cjameshuff-3C0372.12093123052004@news.povray.org...
> In article <40b0d0ad@news.povray.org>,
>  "Eric DeGiuli" <eri### [at] NOSPAMutorontoca> wrote:
>
> > I've just started using POV ray for some scientific visualization but
I'm
> > having problems with density files.  I'm using the patch to allow 16 bit
> > floats as data (
> > http://staff.aist.go.jp/r-suzuki/e/povray/iso/df_body.htm ) - I wish
there
> > was a 3.6 beta available so that I could avoid using the patch!  My data
is
> > a 200x200x32 volume of cloud data, scaled to be between 0 and 0.99.  I'm
> > using the data in a media block, with nothing fancy.  It looks like my
data
> > is being clipped either on import or during rendering, because it should
be
> > really smooth. (see image)
>
> Well, remember that you're viewing it at 8 bits per component. That's
> 256 levels, from 0 to 255. Try rendering to 48 bit PNG and viewing it in
> a program that does dithering. And I couldn't get accurate colors from
> your JPEG, so I'm not really sure what you're seeing. Also, make sure
> you're writing the data in the correct byte order, etc.
>
> Aside from that, this group is for non-binary posts only. If you want to
> post an image, please post it in povray.binaries.images.
>
> -- 
> Christopher James Huff <cja### [at] earthlinknet>
> http://home.earthlink.net/~cjameshuff/
> POV-Ray TAG: <chr### [at] tagpovrayorg>
> http://tag.povray.org/


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