Le 29/09/2013 14:38, Le_Forgeron nous fit lire :
> Le 29/09/2013 14:27, Thomas de Groot nous fit lire :
>> On 29-9-2013 14:02, Thomas de Groot wrote:
>>
>>> Question: If the df3 are made to a unit-sized box, why does the x-axis
>>> need a correction different from object to object?
>>
>> A tentative answer to the question:
>>
>> Could it be that the image format in which the tga slices are rendered
>> influences the final result? In other words, should objects be rendered
>> using a /square/ image format (1:1 ratio) in the first place? I blindly
>> followed Gilles Tran's advice to use a 1.33 ratio. This might be
>> irrelevant for clouds but not for other objects...
>>
>> Thomas
>>
> Do we have the sources of tga2df3 ?
> 
Oki, found in groups a source of tga2df3... it might be time to get
something like png2df3 because the expected tga format is rather limited
and unchecked: targa true color, 8 bits per channel, no alpha, and only
version 1

The pictures are processed as z (the further frame, the deeper),
top left/ top right to bottom right become <0,0>/<0,1> to <1,1> (hence
the -1 factor needed on y in scale for scene)

All pictures must be the same size, but ratio is irrelevant: the
resolution of the picture is transposed to the x,y resolution (or rather
precision) of the df3 file.

The pattern itself consider only the <0,0,0> to <1,1,1> cube, then
computes the cell(s) to use by applying the df3 resolution to get the
indexes on each axis. (some interpolation might wrap as an hypertorus on
the border of the cube: left side is connected to right side, top with
bottom and front with rear, for trilenear interpolation only)

What remains could be the sampling applied on the pattern.

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