Le 25/06/2014 19:34, posfan12 nous fit lire :
> clipka <ano### [at] anonymousorg> wrote:
>> Am 25.06.2014 17:17, schrieb posfan12:

>> (* Heck, I'm sure it can be done by making smart use of what POV-Ray
>> already provides, but it seems such a straightforward use case that
>> POV-Ray should really provide an equally straightforward way of doing it.)
> 
> In GIMP I can convert the grayscale image to an alpha channel, and then apply
> the alpha channel to a 100% black image.
> 
> If there's some internal POV-Ray trick that would be better.

Why do I suddenly think about negative light ? (and  emission/ambient...)

Usual scenes are in the 0 to 1 range for both parameters, but it can be
interesting to look at the combination of -1 , 0 and 1 cases.


Flat object, no shadow : emission 1, light 0, diffuse 1.

Shadow only picture: emission 0, light -1, diffuse 1
(black is full light, the brighter the more deep shadow)


Maybe emission 0.5, light 1, diffuse 0.5 can provide a descent base for
the objects, once you remove the shadow of it using the second picture
(0,-1,1).



-- 
IQ of crossposters with FU: 100 / (number of groups)
IQ of crossposters without FU: 100 / (1 + number of groups)
IQ of multiposters: 100 / ( (number of groups) * (number of groups))

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