Rick DeNatale nous apporta ses lumieres en ce 2005-10-11 10:59:
> I've been using povray for a couple of weeks now. I've got
> two questions which have been bedeviling me.
> 
> 1) Is it possible to set up rendering so that the resulting png has a
> transparent background?  I've tried both
> 
> background { rgbt <0,0,0,1> }
> 
> and
> 
> background { rgbt <1,1,1,1> }
> 
> but when I look at the result in the Gimp, the background seems to be
> black or white respectively.  I've googled and searched these fora but I
> can't seem to find the answer.
> 
> 2) I'm modelling a Mercury spacecraft, which I want to put in low-earth
> orbit, and I'm having problems with the lighting. The light sources
> would be the Sun and the Earth. I've tried a parallel light source for
> the sun, and a large white sphere out of view for the Earth.  I didn't
> seem to be getting much if any "earthshine" this way, so right now I'm
> using a large area light, but I'm still not happy with the results, is
> there a better way to set up this lighting scene?

Point 1) as Marc said, or you can use +UA on the command line. The text box on the
right of the 
resolution drop-list.

Point 2) Place a large sphere with an image_map of the earth where you want the earth
to be and use 
radiosity. The default settings could be OK with a recursion_limit set to 1.

It will look like #global_settings{ radiosity{ recursion_limit 1 } }

Without radiosity, you don't get the inter diffuse reflection.

-- 
Alain
-------------------------------------------------
Disc space -- the final frontier!

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