We’ll start off with importing an image as a plane and applying the alpha maps to that image plane, however this technique can be applied in a number of different ways including in Material Editor. If you don’t know how to import images as planes in Blender, read How To Import Image as Planes in Blender. We’ll be using the Cycles render engine in Blender so before we begin, make sure Cycles is slected as the default render engine by selecting it from the drop down menu at the top of Blender window.
Next, delete the default cube that’s usually loaded from the default start-up file. Select the cube and hit the X key to delete an object.
We’re going to import an image as a 3D plane. To do this go to File > Import > Images as Planes.
Go over to the location of the file that you want to use, select it and click the Import button.
Note: It’s important that the image that you select has an Alpha layer (opaque background) or Blender won’t abe able to apply an Alpha map.
By default your texture will not be displayed. To display the texture, click on the Display/Shade icon at the bottom of the 3D vieport and select to display the Materials in the shading mode. Note that the alpha areas are displayed as completely black.
Now head over to the Materials Tab.
Click on the Use Nodes button.
From the bottom of the 3D Viewport, select the Node Editor from the 3D View button.
Hit SHIFT + A. From the pop-up menu select Shader > Translucent BDSF.
Hit SHIFT + A again, this time from the pop-up menu select Shader > Mix Shader.
Use the following settings to plug the Material Nodes together.
Now Head back to the 3D Viewport.
Select the image plane, hit the TAB key to enter editing mode. Then Hit the U key and select Unwrap option.
From the material pane, while the 3d plane is selected, hit the ASSIGN button.
Hit Shift + Z key in the viewport to preview render. Alpha map should now be applied to your image plane!