"Christopher James Huff" <chr### [at] maccom> wrote in message
news:chr### [at] netplexaussieorg...
> In article <3d528e71@news.povray.org>,
>  "David Wallace" <dar### [at] earthlinknet> wrote:
>
> > I am testing an emission media for use as lava.  The problem is, I am
> > getting a solid white ball in my test sphere:
>
> That's just because the media is too bright, all three colors go above 1
> so the color gets clipped to pure white in the final image. Reduce the
> value given to emission, try 0.01 or 0.05 and adjust until you get what
> you want.

Actually, having tried it out here, I see that the whole media statement
could be trouble for this lava idea. Not sure what the end result wanted is
exactly but that spherical pattern for density is all wrong, seems to me
anyway. The index at 0 is the outside and 1 is inside. Could think of it as
a Earth, having [0 rgb 1] being the core and [1 rgb 0] being the outer
atmosphere where it meets space. frequency -1 reverses the order so I used
that.

Also a couple things to note as well, method 3 intervals are done
automatically-- unless you really want to override that-- and absorption
could be needed too. No idea why ior 1.4 is there but David has his
reasons...

I could go on... (as i try stuff with it here)

How about that amount of empty space and the turbulence? Seems to me the
media would only be a sparkling mass and not solid. I think the amount of
solidness diminishes a lot with that turbulence. And I tried emission 0.3
absorption 0.2 which was okay-looking, as long as turbulence is 0.2 or less.
If more is used the frequency must be increased, or better yet, scale of the
density or a different object used than is now.

Interestingly enough, the media can change drastically as scale, turbulence,
frequency are used differently. The spherical pattern is pretty special as
it is anyway. I kind of knew all this already, of course  :-)  It isn't real
good with frequency, I guess, since by design it is only a unit size without
a repetition of itself to all other points in POV-space unlike most other
patterns.

Maybe the idea was to get a single textured appearance for other things than
that sphere, David will have to confirm this before I think it is pointless
to try and use the density_map as it currently stands. Oh... perhaps it was
intended to have transparent places with it overlaid into a part of a scene?
I should have thought of that, if so.

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