V-Ray for Rhino Manual - Rum

Transparency 材 質 篇 : 透 明 貼 圖 Mapping
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
map directly without transparency map. The black
background of the texture map is blocking 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.
You will get the result as left image if you apply the texture map directly without transparency
map. The black background of the texture map is blocking part of the cup. The image on the right is
rendered with transparency map.
V-Ray for Rhino 51