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

part
of
the
cup
. 
The
image
on
the
right
is
rendered
with
transparency
map
.
Open 
Cup_Red.3dm. 
Here is the object and the transparency map that we will use to create our 
label.
What's Transparency Mapping?
Transparency mapping is another method using Bitmap to create materials. The difference is that this is using 
alpha channel to get rid of unwanted part of the Bitmap, saving only the part covered by alpha channel. This 
is called a mask. 
This is used mostly for creating product logos, stickers and 
numbers. Many users try to avoid using transparency mapping 
and model the actual object in the scene. Although you can 
ignore material settings by creating the actual model of 
objects, that will increase both the number of objects in the 
scene and the file size. The more objects you get, the longer 
the rendering time you would need.
You will get the result as left image if you apply the texture 
m a p d i r e c t l y w i t h o u t t r a n s p a r e n c y m a p . T h e b l a c k 
background of the texture
map
is
blocking
part
of
the
block. 
The
image
on
the
right
is
rendered
with
transparency
map
.
材 質 篇 ： 透 明 貼 圖
Transparency Mapping
V-Ray for SketchUp
50

---

Render it and will get image like below. The 
Transparency map is covering the entire 
chair.
3
. Use Diffuse1 color to edit the color for 
this Transparency map. Click on the 
“
m
” 
at
the
right
of
Color
to
add
more
texture
to
this
map
if
needed
. 
2
. Click on the 
“
m
” 
at
the
right
of
Transparency
under Diffuse to enter the Texture Editor. Load the 
Bitmap for Transparency texture map. Make sure you uncheck the
Tile
first
to
avoid
repeating
this
Bitmap
on
the
object
Use Photoshop, PhotoImpact and similar image editing software to create black and white image 
and save as .bmp, .jpg or .png which are the formats accepted by V-Ray.
1
. Click on the chair and open its Material Editor
. 
Open 
; 
right
click
on
Diffuse
Layers
to
add
a
new
layer
and
you
will
have
the
dialog
window
as
image on the right. A Diffuse1 control panel 
is added under the Diffuse
Chair_Red