"Ross" <rli### [at] everestkcnet> wrote in message
news:42ada0e8$1@news.povray.org...
> Hi. After seeing Star Wars this past weekend

Hiya Ross. I still haven't seen the Episode 3 yet. Sounds like it had
something for you, at least.

> was thinking of a laser blast. I managed to get a nice green laser
> by using two emissive medias, one with a green cylindrical density and one
> with a white cylindrical density slightly smaller than the green, all
> contained in a CSG merge of a cylinder and two spheres. It looks pretty
> good
> I think. I know that emmisive media doesn't really emit light, but I was
> naively expecting that it's color would affect nearby objects when
> radiosity
> is used, in the same way that a white sphere would pick up some green from
> a
> green wall. in the global settings, media was set to "on".

Should be okay then. media on goes in radiosity block, just so you weren't 
mistakenly putting it into global_settings only.

> Is the above the expected behavior of emitting media? if this is the
> expected behavior, how would you go about faking a green light emitting
> from
> the media? just attach a small light_source to the laser blast object with
> a
> suitable fade power and fade distance?

area_light like that could enhance it a lot, sure, but then you need to
either let it interact with the media or tell it not to.

Checking here with a test media object and radiosity I see you might need to
increase 'count' to 500 or more, especially if the laser isn't in close
proximity to the other scene objects. Perhaps even increasing 'brightness'
to more than 1. In fact, there might be other settings which could prove
better but it looks to me like a light would be less likely to cause trouble
such as radiosity can if you attempt to maximize the interactions from it
(texture tweaking, etc.).

Bob Hughes

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