In article <web.3e3ffebcc7b69b7a1c4fca030@news.povray.org>,
 "Neil Conway" <nei### [at] yahoocom> wrote:

> All I really need is to have a volumetric emission source (e.g. my plasma)
> with proper reflections from the walls etc.  Isn't that what Tom's example
> does?  (I haven't figured out Warp's example very thoroughly yet.)

You really need to define your problem more clearly: what do you mean by 
"proper reflections"? What is your goal, a picture that looks like the 
interior of the tokamak, or an actual simulation? If the latter is the 
case, a custom raytracer will probably be needed.

POV is currently only capable of handling diffuse reflections of light 
emitted by media, such as light bouncing off a sheet of paper, or media 
seen directly. Specular reflections, like light bouncing off a mirror, 
are not handled. It techni cally would be possible: fire photons in 
random directions from random locations in the media container, but it 
would be extremely CPU and memory intensive to get good accuracy. If you 
want to take scattering and absorption of the media into account instead 
of just emission, it would would take massive amounts of processing 
power...it is probably impractical on any existing hardware.

However, if everything in the scene (except the plasma) is highly 
reflective, these photons would have little contribution. Ordinary 
raytracing can handle this situation pretty accurately, photons mainly 
exist for caustics and radiosity for diffusely scattered light. Straight 
raytracing and radiosity will cover most effects.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

Post a reply to this message