projected_through only seems to work when the light source is below the
projected_through object. And the light is projected on the ceiling.
Also if the light source is close in height to the object and to the
side, the light is projected vertically upward and not through the object.
This happens in Pov-Ray 3.5, 3.6 and RC3.
I would appreciate it if someone would either confirm that this is


-- 
Regards
     Stephen

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On 17/02/2011 1:22 PM, Stephen wrote:


Well it looks to me as if a point light projects a vertical cone with a 
half angle of 30 degrees that will interact with the projected_through 
object. If you rotate the light then the cone of interaction rotates too.
Is this by design?


-- 
Regards
     Stephen

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Am 17.02.2011 14:22, schrieb Stephen:


> projected_through only seems to work when the light source is below the
> projected_through object. And the light is projected on the ceiling.
> Also if the light source is close in height to the object and to the
> side, the light is projected vertically upward and not through the object.
> This happens in Pov-Ray 3.5, 3.6 and RC3.
> I would appreciate it if someone would either confirm that this is


It's pretty simple: The projected_through object "sticks" to the light 
source when it is translated around.

So if you want to know where your projected_through object /really/ is, 
you'll need to use

#declare Target = box {...}
union {
   light_source {
     ...
     projected_through { Target }
   }
   object { Target no_shadow }
}

(Also note the no_shadow flag on the target.)


As another note: Are you sure projected_through really does what you 
think it does? I'm still wondering what you intend to use it for in your 
lamp scene.

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On 17/02/2011 3:30 PM, clipka wrote:

> It's pretty simple: The projected_through object "sticks" to the light
> source when it is translated around.
>
> So if you want to know where your projected_through object /really/ is,
> you'll need to use
>
> #declare Target = box {...}
> union {
> light_source {
> ...
> projected_through { Target }
> }
> object { Target no_shadow }
> }
>

Thanks, Christoph. I knew I was doing something wrong.

> (Also note the no_shadow flag on the target.)
>
>
Are you sure about the no_shadow flag? I'm sure I read that it was implicit.


> As another note: Are you sure projected_through really does what you
> think it does? I'm still wondering what you intend to use it for in your
> lamp scene.

Thanks, I know it won't do what I'd like it to do but I just wanted to 
get it working and understand it.

-- 
Regards
     Stephen

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Am 17.02.2011 17:11, schrieb Stephen:
> On 17/02/2011 3:30 PM, clipka wrote:
>
>> It's pretty simple: The projected_through object "sticks" to the light
>> source when it is translated around.
>>
>> So if you want to know where your projected_through object /really/ is,
>> you'll need to use
>>
>> #declare Target = box {...}
>> union {
>> light_source {
>> ...
>> projected_through { Target }
>> }
>> object { Target no_shadow }
>> }
>>
>
> Thanks, Christoph. I knew I was doing something wrong.
>
>> (Also note the no_shadow flag on the target.)
>>
>>
> Are you sure about the no_shadow flag? I'm sure I read that it was
> implicit.

Not if you also add the object to the scene, as in the sample above. It 
/may/ be reduntant there as well, but I'd prefer not to rely on it. (At 
any rate it speeds up rendering, if only by a few nanoseconds ;-))

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On 18/02/2011 12:13 AM, clipka wrote:
>> Are you sure about the no_shadow flag? I'm sure I read that it was
>> implicit.
>
> Not if you also add the object to the scene, as in the sample above. It
> /may/ be reduntant there as well, but I'd prefer not to rely on it. (At
> any rate it speeds up rendering, if only by a few nanoseconds ;-))

:-D

-- 
Regards
     Stephen

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