S t e
p 6 :
Intermediate conclusion
You have now achieved a better understanding
of how shadows should be cast in order for them to be the highest quality
as possible. You have understood that BufSi is the key to quality, but
also the cruder mean to achieve it, because it asks for a lot of memory.
As a thumb of rule, let say the following :
-
Try to set all your SpotSi within 45.00 and
60.00 degrees values.
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Set Samples to 5.
-
Try to set BufSi to 768 or 1024.
With this in mind, about 70% of your renders
will have the best quality/render-time ratio. If you have enough RAM memory
and if time isn't a factor for you (eg, you are dealing with a still picture,
not an animation), then you can set the BufSi to the highest value you
choose. A high BufSi combined to low SpotSi values and high Samples gives,
of course, the very best results Blender can let you achieve.
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BufSi set to 2560, SpotSi set to 60.00
degrees and Samples set to 5
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Zoom: It is up to you to choose wether
you really need such a shadow quality!
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Fine tuning your shadows
"Only Shadow" button and
"Energy" value
So far, we used our Spot to cast both
light and shadow. This is why in our latest renderings, we can see the
spot light on the floor and on the walls. Most of the time, this isn't
the effect you want to achieve. Instead, you would like to dissociate shadows
from the light source. This is easily done : set a few Lamps, or Hemis,
or Suns (whatever you like) for your whole scene. Then add many Spot lamps
(ideally, one for each object for which you'd like to see a shadow, or
at least one for a group of close casting shadows objects) for which you
turn the "Only shadow" button along with the "Shadows" button. Et voilà
! Your Spots only cast shadows and don't add to the luminosity of the scene
!
Alas, the shadow deepness increases dramatically.
In order to compensate this, you can play with the Energy value of the
Spot. As a rule of thumb, a middle value gives almost the same result as
a Spot casting both light and shadows. But sometimes, you'll like it with
pitch dark shadows !
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Lamp, Spot with "Only shadow" turned
on and Spot Energy set to 1.000
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The same, but with Spot Energy set
to 0.500
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