On Mon, 15 Mar 2004 21:19:25 +0000, IMBJR <no### [at] spamhere> wrote:

> On Mon, 15 Mar 2004 09:31:18 -0000, Phil Cook
> <phi### [at] nospamdeckingdealscouk> wrote:
>
>> On Sat, 13 Mar 2004 15:58:50 +0000, IMBJR <no### [at] spamhere> wrote:
>>
>>> On Fri, 12 Mar 2004 23:18:50 -0500, "Slime" <slm### [at] slimelandcom> wrote:
>>>
>>>>> Currently, I've a cylinder of light
>>>>
>>>> Hmm, I vaguely remember other people having troubles with cylinder
>>>> lights
>>>> and photons... but I don't remember what the solutions were.
>>>
>>> LOL
>>>
>>> Cheers, that fills me with hope!
>>>
>>>>
>>>> - Slime
>>>> [ http://www.slimeland.com/ ]
>>>>
>>
>> Hopefully you won't object to comments from a newbie, but as I've been
>> messing with this sort of thing I may know what's happening.
>> The parallel light source beam diameter seems to be controlled by the
>> tightness keyword, as for reflecting the light beam off a reflected
>> surface; it doesn't.
>> As they say a picture is worth a thousand words;
>>
<snip code>
>>
>> As you can see from the top view the light beam isn't reflected, but if
>> you switch to the other camera view the white sphere is reflected in the
>> prism. The only way round this I think is to point a cylinder light 
>> where
>> the beam should reflect.
>>
>> Hope this helps
>
> Interesting. I've had a play with your scene and still can't see why
> this does not work. After all I'm sure the documentation does talk
> about photons being trapped/held/sampled in media.

Yeah I've fiddled with it at lot too, add a new camera at:

location <10,7,3>
look_at <-10,3,3>

add a box at:

box{0,<-10,10,-100> rotate y*22.5 translate <-10,0,10> pigment {rgb 0.8} 
finish{reflection {1.0} ambient 0.5 diffuse 1}}

then switch the LightReflector to ambient 0.5 diffuse 1

you can see that the light beam is being calculated as there is a patch on 
the box however note the lack of a shadow from the first sphere which 
should appear in the middle of it, also note the lack of the reflected 
shadow in the box part which is showing the reflection of the 
LightReflector.

So unless there's something I'm missing it appears POV-Ray can't do this 
sort of thing with media.

--
Phil

-- 
All thoughts and comments are my own unless otherwise stated and I am 
happy to be proven wrong.

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