U g I n f o r d e s I g n e r s

V-Ray for SketchUp
59

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Bitmap Environment light source
If user does not have HDR image, a regular Bitmap can be also used as Environment light source. 
Although a
normal
Bitmap
doesn
'
t have the same ability to create as dynamic an environment, 
normal images are very easy to get. As long as you pick the right Bitmap and control the Intensity 
well, it can still be a very good Environment light source.
The three images on the right are rendered with different Bitmap. Compare to those rendered with 
HDR images, it is not as easy to determine the direction of the light and the shadows are not very 
clear.
V-Ray for SketchUp
60

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This example shows that Environment light in semi-open spaces usually doesn’t lead to a proper solution the 
first time.
When begining to set up the illumination for interior space, a first step should be to check how many openings 
in the scene allow environment light to come in. This includes transparent object like window or door. It is 
also important to know how many lights are intended to be in the final scene, as well as what time of day the 
rendering is meant to depict. These are all very helpful for setting the Environment light correctly.
Increase the GI to 8 and render again. The 
result is closer to reasonable illumination.
Increase the GI Intensity to 4 and render it 
again. The result is as below, a little bit 
brighter this time
Environment light source for semi-open space
We used open space to discuss Environment light source for last example
. 
Now
is
time
to
use
semi
-
open
interior
space
for
this
example
to
see
differences
between
interior and exterior illumination
Open file: 
. In the scene is a enclosed cube with an open on the top. There 
are some objects
placed
on
the
wall
next
to
the
opening
wall
and
there
is
no
light
in
the
box
. 
All
objects
used
Val
190 
gray
color
, 
current
GI
Intensity
is
2, 
color
is
light
blue
. 
Render
it
and
you
will
get
the
almost
black
image
on
the
right
. 
The
result
is
due
to
no
light
in
the
scene
and
only
a
small
opening
allows
the
Environment
light
come
in
. 
GI Environment-01.3dm