At first, make a white ball and then make a red box, which is bigger than
the ball, in front of the ball.

If I use the command "filter" or "transmit", I could see the ball through
the box.

But the color of ball(white) seem to be redder and dimmer than its original
because the light traverse through the red box.

If I put more red boxes in front of the ball, I will not be able to see the
ball because many boxes screen the light emitted from the white ball.

How can I see the white ball even if there are many boxes between the ball
and the camera?

Thank you.

JH

-- 
==========================================
 Yonsei University, Department of Astronomy
 Seoul, South Korea
 Graduate Student, Room #703
 Joo Heon Yoon in GEM
 jhy### [at] galaxyyonseiackr
==========================================

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yoon nous apporta ses lumieres en ce 17/07/2006 12:05:
> At first, make a white ball and then make a red box, which is bigger than
> the ball, in front of the ball.
> 
> If I use the command "filter" or "transmit", I could see the ball through
> the box.
> 
> But the color of ball(white) seem to be redder and dimmer than its original
> because the light traverse through the red box.
> 
> If I put more red boxes in front of the ball, I will not be able to see the
> ball because many boxes screen the light emitted from the white ball.
> 
> How can I see the white ball even if there are many boxes between the ball
> and the camera?
> 
> Thank you.
> 
> JH
> 
As you add transparent box, you need to trace through more and more surfaces. 
The maximum number of surfaces you can pass is set by max_trace_level, it's 
default value is 5. So, with 3 box you get 2 levels for each box (front and back 
face) and 1 for the sphere, making a total of 7. You thus need to set 
max_trace_level 7 to be able to see the sphere, otherwize, you see black.
Add:
global_settings{ max_trace_level TraceValue} to your scene. Adjust TraceValue so 
that your transparency is completely restored. The global_settings{} block can 
be about anywhere in the scene, but is usualy placed near the beggining.

-- 
Alain
-------------------------------------------------

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"yoon" <jhy### [at] galaxyyonseiackr> wrote:
> At first, make a white ball and then make a red box, which is bigger than
> the ball, in front of the ball.
>
> If I use the command "filter" or "transmit", I could see the ball through
> the box.
>
> But the color of ball(white) seem to be redder and dimmer than its original
> because the light traverse through the red box.
>
> If I put more red boxes in front of the ball, I will not be able to see the
> ball because many boxes screen the light emitted from the white ball.
>
> How can I see the white ball even if there are many boxes between the ball
> and the camera?
>
> Thank you.
>
> JH
>
> --
> ==========================================
>  Yonsei University, Department of Astronomy
>  Seoul, South Korea
>  Graduate Student, Room #703
>  Joo Heon Yoon in GEM
>  jhy### [at] galaxyyonseiackr
> ==========================================

absolutly untested....
but I first would try out:


The pigment-color of the box  = "Clear"

The pigment-color of the sphere = white*1.2"
(to lighten the "white" of the sphere)

Post a reply to this message

Thank you.

But, both methods do not work.

I put a large number of boxes in front of the ball and the maximum of the 
"max_trace_level" 256. It is not enough large I think...

"Meothuru" <nomail@nomail> wrote in message 
news:web.44bf14fc8936040dbc6f282e0@news.povray.org...
> "yoon" <jhy### [at] galaxyyonseiackr> wrote:
>> At first, make a white ball and then make a red box, which is bigger than
>> the ball, in front of the ball.
>>
>> If I use the command "filter" or "transmit", I could see the ball through
>> the box.
>>
>> But the color of ball(white) seem to be redder and dimmer than its 
>> original
>> because the light traverse through the red box.
>>
>> If I put more red boxes in front of the ball, I will not be able to see 
>> the
>> ball because many boxes screen the light emitted from the white ball.
>>
>> How can I see the white ball even if there are many boxes between the 
>> ball
>> and the camera?
>>
>> Thank you.
>>
>> JH
>>
>> --
>> ==========================================
>>  Yonsei University, Department of Astronomy
>>  Seoul, South Korea
>>  Graduate Student, Room #703
>>  Joo Heon Yoon in GEM
>>  jhy### [at] galaxyyonseiackr
>> ==========================================
>
> absolutly untested....
> but I first would try out:
>
>
> The pigment-color of the box  = "Clear"
>
> The pigment-color of the sphere = white*1.2"
> (to lighten the "white" of the sphere)
>
>
>
>
>
>
>
>

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yoon nous apporta ses lumieres en ce 20/07/2006 11:22:
> Thank you.
> 
> But, both methods do not work.
> 
> I put a large number of boxes in front of the ball and the maximum of the 
> "max_trace_level" 256. It is not enough large I think...
> 
Why do you want to see trough over 128 boxes?
If it's to increase the colouring, you should be better to use this:
interior{fade_color Red fade_distance 1}
If you reduce the fade_distance, the colouring will increase.
By the way, the ball (sphere) don't emit light, it's normaly lighted by a 
light_source.
The only way that an object can effectively emit light, is in a radiosity scene 
if the object have a non-zero ambient value.

-- 
Alain
-------------------------------------------------
'I had to hit him -- he was starting to make sense.'

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