Hi.

I have a scene, which already takes around 6 days to create the photon map 
for, if it is done in the same resolution like the remaining scene.

I would like to know, if it is possible to use a lower resolution (let's 
say: 400x300) for the photon map (with the "save_file" option enabled), and 
then to stop and continue the scene in a high resolution (now with the 
"load_file" option enabled).

Sven

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Sven Littkowski escribió:
> I would like to know, if it is possible to use a lower resolution (let's 
> say: 400x300) for the photon map (with the "save_file" option enabled), and 
> then to stop and continue the scene in a high resolution (now with the 
> "load_file" option enabled).


It's possible. The photon map is independent from the image resolution.

Which also means that calculating the photon map when rendering at 
400x300 will take exactly the same time as any other higher resolution.

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Sven Littkowski wrote:
> Hi.
> 
> I have a scene, which already takes around 6 days to create the photon map 
> for, if it is done in the same resolution like the remaining scene.
> 
> I would like to know, if it is possible to use a lower resolution (let's 
> say: 400x300) for the photon map (with the "save_file" option enabled), and 
> then to stop and continue the scene in a high resolution (now with the 
> "load_file" option enabled).

Sure, I do it myself.  However, since the photon map is independent from 
the scene resolution, you can set the image size absurdly low (like +w1 
+h1) and still get a full-quality photon map.

-- 
...Ben Chambers
www.pacificwebguy.com

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Hi Ben,

but even so, based on what I heard already, meanwhile, the photon map would 
still take 6 days, right?

Sven



"Chambers" <ben### [at] pacificwebguycom> schrieb im Newsbeitrag 
news:479bdf30$1@news.povray.org...
> Sven Littkowski wrote:
>> Hi.
>>
>> I have a scene, which already takes around 6 days to create the photon 
>> map for, if it is done in the same resolution like the remaining scene.
>>
>> I would like to know, if it is possible to use a lower resolution (let's 
>> say: 400x300) for the photon map (with the "save_file" option enabled), 
>> and then to stop and continue the scene in a high resolution (now with 
>> the "load_file" option enabled).
>
> Sure, I do it myself.  However, since the photon map is independent from 
> the scene resolution, you can set the image size absurdly low (like +w1 
> +h1) and still get a full-quality photon map.
>
> -- 
> ...Ben Chambers
> www.pacificwebguy.com

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try using image_width to choose the photon count/spacing
Sven Littkowski napsal(a):
> Hi Ben,
> 
> but even so, based on what I heard already, meanwhile, the photon map would 
> still take 6 days, right?
> 
> Sven
> 
> 
> 
> "Chambers" <ben### [at] pacificwebguycom> schrieb im Newsbeitrag 
> news:479bdf30$1@news.povray.org...
>> Sven Littkowski wrote:
>>> Hi.
>>>
>>> I have a scene, which already takes around 6 days to create the photon 
>>> map for, if it is done in the same resolution like the remaining scene.
>>>
>>> I would like to know, if it is possible to use a lower resolution (let's 
>>> say: 400x300) for the photon map (with the "save_file" option enabled), 
>>> and then to stop and continue the scene in a high resolution (now with 
>>> the "load_file" option enabled).
>> Sure, I do it myself.  However, since the photon map is independent from 
>> the scene resolution, you can set the image size absurdly low (like +w1 
>> +h1) and still get a full-quality photon map.
>>
>> -- 
>> ...Ben Chambers
>> www.pacificwebguy.com 
> 
>

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Hmm... THAT sounds interesting and promising, Jan. I looked into the POV 
help file, and see the keywords "image_width" and "image_height". And also 
some examples, how to use them. I really think, this could shorten the 
calculation time, if I can find out, how to use them properly in connection 
with my photon map creation.

Jan, can you give me some more advice in this? If you like, I could post the 
scene file to you. Please let me know. Thanks,

Sven





"Jan Dvorak" <jan### [at] centrumcz> schrieb im Newsbeitrag 
news:479c31b4$1@news.povray.org...
> try using image_width to choose the photon count/spacing
> Sven Littkowski napsal(a):
>> Hi Ben,
>>
>> but even so, based on what I heard already, meanwhile, the photon map 
>> would still take 6 days, right?
>>
>> Sven
>>
>>
>>
>> "Chambers" <ben### [at] pacificwebguycom> schrieb im Newsbeitrag 
>> news:479bdf30$1@news.povray.org...
>>> Sven Littkowski wrote:
>>>> Hi.
>>>>
>>>> I have a scene, which already takes around 6 days to create the photon 
>>>> map for, if it is done in the same resolution like the remaining scene.
>>>>
>>>> I would like to know, if it is possible to use a lower resolution 
>>>> (let's say: 400x300) for the photon map (with the "save_file" option 
>>>> enabled), and then to stop and continue the scene in a high resolution 
>>>> (now with the "load_file" option enabled).
>>> Sure, I do it myself.  However, since the photon map is independent from 
>>> the scene resolution, you can set the image size absurdly low (like +w1 
>>> +h1) and still get a full-quality photon map.
>>>
>>> -- 
>>> ...Ben Chambers
>>> www.pacificwebguy.com
>>

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You might decide to shoot image_width*image_height*some_constant 
photons. Some_constant==1 might work well but feel free to increase for 
high quality or decrease for faster render. Use the count keyword and 
watch POV-ray do its best.
Sven Littkowski napsal(a):
> Hmm... THAT sounds interesting and promising, Jan. I looked into the POV 
> help file, and see the keywords "image_width" and "image_height". And also 
> some examples, how to use them. I really think, this could shorten the 
> calculation time, if I can find out, how to use them properly in connection 
> with my photon map creation.
> 
> Jan, can you give me some more advice in this? If you like, I could post the 
> scene file to you. Please let me know. Thanks,
> 
> Sven
> 
> 
> 
> 
> 
> "Jan Dvorak" <jan### [at] centrumcz> schrieb im Newsbeitrag 
> news:479c31b4$1@news.povray.org...
>> try using image_width to choose the photon count/spacing
>> Sven Littkowski napsal(a):
>>> Hi Ben,
>>>
>>> but even so, based on what I heard already, meanwhile, the photon map 
>>> would still take 6 days, right?
>>>
>>> Sven
>>>
>>>
>>>
>>> "Chambers" <ben### [at] pacificwebguycom> schrieb im Newsbeitrag 
>>> news:479bdf30$1@news.povray.org...
>>>> Sven Littkowski wrote:
>>>>> Hi.
>>>>>
>>>>> I have a scene, which already takes around 6 days to create the photon 
>>>>> map for, if it is done in the same resolution like the remaining scene.
>>>>>
>>>>> I would like to know, if it is possible to use a lower resolution 
>>>>> (let's say: 400x300) for the photon map (with the "save_file" option 
>>>>> enabled), and then to stop and continue the scene in a high resolution 
>>>>> (now with the "load_file" option enabled).
>>>> Sure, I do it myself.  However, since the photon map is independent from 
>>>> the scene resolution, you can set the image size absurdly low (like +w1 
>>>> +h1) and still get a full-quality photon map.
>>>>
>>>> -- 
>>>> ...Ben Chambers
>>>> www.pacificwebguy.com
>

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Shooting the image with those keywords... Hmm, do you mean that I need to 
put these two keywords inside the camera directive? To be honest, due the 
lack of experience and knowledge with these two keywords, i would just like 
to ask you to give an example where and how to use these two keywords in a 
scene. I think, that should help me.

Thanks, Jan.

Sven



"Jan Dvorak" <jan### [at] centrumcz> schrieb im Newsbeitrag 
news:479cff7f@news.povray.org...
> You might decide to shoot image_width*image_height*some_constant photons. 
> Some_constant==1 might work well but feel free to increase for high 
> quality or decrease for faster render. Use the count keyword and watch 
> POV-ray do its best.
> Sven Littkowski napsal(a):
>> Hmm... THAT sounds interesting and promising, Jan. I looked into the POV 
>> help file, and see the keywords "image_width" and "image_height". And 
>> also some examples, how to use them. I really think, this could shorten 
>> the calculation time, if I can find out, how to use them properly in 
>> connection with my photon map creation.
>>
>> Jan, can you give me some more advice in this? If you like, I could post 
>> the scene file to you. Please let me know. Thanks,
>>
>> Sven
>>
>>
>>
>>
>>
>> "Jan Dvorak" <jan### [at] centrumcz> schrieb im Newsbeitrag 
>> news:479c31b4$1@news.povray.org...
>>> try using image_width to choose the photon count/spacing
>>> Sven Littkowski napsal(a):
>>>> Hi Ben,
>>>>
>>>> but even so, based on what I heard already, meanwhile, the photon map 
>>>> would still take 6 days, right?
>>>>
>>>> Sven
>>>>
>>>>
>>>>
>>>> "Chambers" <ben### [at] pacificwebguycom> schrieb im Newsbeitrag 
>>>> news:479bdf30$1@news.povray.org...
>>>>> Sven Littkowski wrote:
>>>>>> Hi.
>>>>>>
>>>>>> I have a scene, which already takes around 6 days to create the 
>>>>>> photon map for, if it is done in the same resolution like the 
>>>>>> remaining scene.
>>>>>>
>>>>>> I would like to know, if it is possible to use a lower resolution 
>>>>>> (let's say: 400x300) for the photon map (with the "save_file" option 
>>>>>> enabled), and then to stop and continue the scene in a high 
>>>>>> resolution (now with the "load_file" option enabled).
>>>>> Sure, I do it myself.  However, since the photon map is independent 
>>>>> from the scene resolution, you can set the image size absurdly low 
>>>>> (like +w1 +h1) and still get a full-quality photon map.
>>>>>
>>>>> -- 
>>>>> ...Ben Chambers
>>>>> www.pacificwebguy.com
>>

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global_settings{
   photons{
     count image_width*image_height
     ...
   }
   ...
}

untested
Sven Littkowski napsal(a):
> Shooting the image with those keywords... Hmm, do you mean that I need to 
> put these two keywords inside the camera directive? To be honest, due the 
> lack of experience and knowledge with these two keywords, i would just like 
> to ask you to give an example where and how to use these two keywords in a 
> scene. I think, that should help me.
> 
> Thanks, Jan.
> 
> Sven
> 
> 
> 
> "Jan Dvorak" <jan### [at] centrumcz> schrieb im Newsbeitrag 
> news:479cff7f@news.povray.org...
>> You might decide to shoot image_width*image_height*some_constant photons. 
>> Some_constant==1 might work well but feel free to increase for high 
>> quality or decrease for faster render. Use the count keyword and watch 
>> POV-ray do its best.
>> Sven Littkowski napsal(a):
>>> Hmm... THAT sounds interesting and promising, Jan. I looked into the POV 
>>> help file, and see the keywords "image_width" and "image_height". And 
>>> also some examples, how to use them. I really think, this could shorten 
>>> the calculation time, if I can find out, how to use them properly in 
>>> connection with my photon map creation.
>>>
>>> Jan, can you give me some more advice in this? If you like, I could post 
>>> the scene file to you. Please let me know. Thanks,
>>>
>>> Sven
>>>
>>>
>>>
>>>
>>>
>>> "Jan Dvorak" <jan### [at] centrumcz> schrieb im Newsbeitrag 
>>> news:479c31b4$1@news.povray.org...
>>>> try using image_width to choose the photon count/spacing
>>>> Sven Littkowski napsal(a):
>>>>> Hi Ben,
>>>>>
>>>>> but even so, based on what I heard already, meanwhile, the photon map 
>>>>> would still take 6 days, right?
>>>>>
>>>>> Sven
>>>>>
>>>>>
>>>>>
>>>>> "Chambers" <ben### [at] pacificwebguycom> schrieb im Newsbeitrag 
>>>>> news:479bdf30$1@news.povray.org...
>>>>>> Sven Littkowski wrote:
>>>>>>> Hi.
>>>>>>>
>>>>>>> I have a scene, which already takes around 6 days to create the 
>>>>>>> photon map for, if it is done in the same resolution like the 
>>>>>>> remaining scene.
>>>>>>>
>>>>>>> I would like to know, if it is possible to use a lower resolution 
>>>>>>> (let's say: 400x300) for the photon map (with the "save_file" option 
>>>>>>> enabled), and then to stop and continue the scene in a high 
>>>>>>> resolution (now with the "load_file" option enabled).
>>>>>> Sure, I do it myself.  However, since the photon map is independent 
>>>>>> from the scene resolution, you can set the image size absurdly low 
>>>>>> (like +w1 +h1) and still get a full-quality photon map.
>>>>>>
>>>>>> -- 
>>>>>> ...Ben Chambers
>>>>>> www.pacificwebguy.com
> 
>

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[Posting to newsgroup since other people may be interested]

Now that you sent me the files... The scene is quite slow to render 
(55pps) even without radiosity or photons. I tried with photons, and 
there were very long periods where the "photons shot" counter didn't 
change, which could mean POV-Ray is shooting lots of photons but 
"missing the object".

What I'm suspecting is that POV-Ray is creating sub-optimal bounding 
boxes. I see a lot of difference objects on your scene. POV-Ray 
sometimes does a bad job bounding difference/intersection CSG.

I'm now rendering a 160x120 image to see the raytrace statistics at the 
end, and see if there were a lot of misses or not. Stay tuned...

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