Le 25/04/2011 10:20, mont29 nous fit lire :
> 
> Le_Forgeron <jgr### [at] freefr> wrote:
>> Le 25/04/2011 00:11, mont29 nous fit lire :
>>> So, I’d like to know if there is a way for an external program (here, Blender
>>> and its pov render script) to get partial rendered pictures, to give the user
>>> something else than a black screen during whole render ?
>>>
>>> For example, would it be possible for pov ray to periodically write what has
>>> already been rendered in the output file, instead of only creating and writing
>>> this one once render is completed ?
>>
>> The image format (whatever could it be with +F...) in 3.7 is generated
>> only at the very end of the rendering process.
> 
> Thanks for confirming that…
> 
>> Nevertheless, if you use the intermediate file storage (which slow down
>> the render process if it is quick), which is used for big resolution (as
>> it is triggered by default for 128 MB of raw buffer)
>> ( see http://wiki.povray.org/content/Documentation:Reference_Section_1
>> +MI option), you could get some data. I guess I would have to document
>> that file (fixing it forever... )
> 
> I have seen this option, and tried to use it, but I couldn’t figure out where
> that intermediary file is stored… And I suppose it does not use a standard
> format (like png, tga, etc.)? Anyway, a 800*600 is about 1.5Mb (or 2Mb with
> alpha), and the minimum buffer size is 1Mb, so it wouldn’t be that much useful.
> 

800 x 600 is about 9 megabytes of storage in raw.
(5 COLC (== float) per pixel, with 32 bits per float, usually)

At the very end of the file there is 3 extra size_type, which hold : the
size of the pixel_type, the width of the picture, the height of the
picture (in that order).

Once created, the file keep its size.

Position in the file of pixel (x,y) is (y * witdth + x)*size_of_pixel_type

A gap can exist between the last pixel and the 3 size_type at the end.

pixel_type is an array of 5 COLC.
(order is Red, Green, Blue, Filter, Transmit)

The file is a temporary file, usually in the local directory unless you
tuned it otherwise. (on unix : it's /tmp/pov$$ with $$ the process id)

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