Kenneth nous apporta ses lumieres en ce 21-01-2007 13:00:
> "Kenneth" <kdw### [at] earthlinknet> wrote:
>> Le Forgeron <jgr### [at] freefr> wrote:



>>> It might be different if instead of an <area light> object, you used
>>> a real collection of point lights...
>> An interesting idea. I'll do an experiment, to compare this to an area light
>> (of the same number of point lights), to see just what a visual difference
>> there might be on a scene's illuminated objects, as well as the shadow
>> qualities produced.


> Of course, an area light can use jitter, which would automatically make the
> shadows (from the area light's discreet point lights) smoother, compared to
> using a similar array of "real" point lights. The latter would simply cast a
> number of separate, discreet shadows, all slightly displaced.

> It would still be interesting to see the difference in the surface
> illumination of an object, comparing both methods.  I.e., the area light's
> single "point light" direct illumination vs. an array of real point lights.

> Here's a really wacky experiment to try (though I haven't done ot yet):
> Start with two copies of the same object. Use the area light to create the
> shadows on one copy--but use the no_image tag for that object, so it's
> invisible.  Then light the 2nd copy with the array of "real" point
> lights--but use the no_shadow tag for that one. So what you end up with is
> the object lit by multiple real point lights, with the shadow created by
> the area light.  The best(?) of both worlds!

> KW




With the no_shadow, the lights will illuminate the shadowed area just as if the 
object was not there at all, making the shadow very faint.
What you can do, is to use an aray of smaller area_light. Something like a 3*3 
aray of smaler area_light. That way, you can have very smooth shadows, save 
rendering time and have an illumination and highlights closer to real life. Set 
the specular or phong to be rather large.

-- 
Alain
-------------------------------------------------
Don't cry because it is over, smile because it happened.

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