Alain <kua### [at] videotronca> wrote:

> > background {
> >    color rgb < 0.60, 0.70, 0.95 >
> > }
> > camera {
> >    location <0, 15, -60>
> >   direction <0, 2,  1>
> >    right x*1.33
> >   look_at <0,15,0>
> > }
> > light_source {
> >    <0,28,0> // position of a coner of the light plane
> >    rgb<1.0,1.0,1.0>
> >    area_light <3, 0, 0>, <0, 3, 0>, 2, 2 // light plane's edges; m by n bulbs
> >   adaptive 1 // if on, some rays will not be traced
> >   jitter // randomization of bulb's positions, emulating fuzzy shadow edges
> > }
> >
>
> The adaptive feature value is NOT a boolean value but an initial or
> minimal subdivision value.
> It's turned ON by the sole presence of the keyword "adaptive" followed
> by some value, even zero.
>
> adaptive 0 will shoot at least 4 rays in a 2 by 2 array, the size of
> your array.
> adaptive 1 will attempt to shoot at least 9 rays in a 3 by 3 array, but
> your array, at 2 by 2, is not large enough.
> adaptive 2 will attempt to shoot at least 25 rays in a 5 by 5 array
> If a dimention for the sublights is to small in any direction to allow
> for the desired minimal subdivision, it won't attempt to subdivide further.
> Using an area_light 3*x, 3*y, 2, 2 with adaptive is totaly pointless.
>
> Using this area_light setting is prety fast and gives very smooth results:
> area_light 3*x, 3*y, 33 33 adaptive 0
> You can go overboard:
> area_light 3*x, 3*y, 1025 1025 adaptive 0
> whitch is almost as fast and so smooth that jitter not usefull.
>
>
>
> Alain
Thank you ,My question is that in the render result picture the black area
should be transparent,because my bitmap have alpha channel .

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