Transparency maps

How do I do them? How do they work? Can they be done in Blender? If so, how?




i assume you mean how to use materials/textures with parts of them being transparent.

basically having transparent materials involves the usage of a texture, which tells the shader WHERE the transparent parts should be. there are two methods: one utilizes a color, which is defined as transparent. this means, each part of the texture that is, let’s say, white, becomes transparent (or was it black? one of the two is taken if you you use procedurals as alpha maps).

the second way is to use image maps with an additional alpha channel embedded into them (Red, Green, Blue are the basic three channels). you can make such images in PS or GIMP. once loaded into blender, you have to tell blender to use the alpha channel by activating the button “use alpha” in the image-texture buttons. then, in the material buttons, you activate “Alpha” in the map-to panel. done.

this is well documented on


I have a black, white, and gray image that is supposed to be a transparency map. I think the black is visible, the gray is partial, and the white is invisible. But how do I make blender use it?

under texture settings hit
[calc alpha]

under material settings:

set “alpha” to yellow under the “map to” tab…
yellow because this will make black opaque and white transparent
usually its the other way around.
find the alpha slider (under the RGB sliders)and drag it to 0

under “Mirror Transp” tab hit either ztransp or raytransp.