Cycles - Baking Transparent Background So I tried a few different answers that I found here, and I feel that this is possibly a duplicate question, but everything I have tried from the other solutions hasn't worked.

Basically I am trying to bake a material to a texture that will be used in Unity, but every test gives me a black background image.

In the image below, the top image texture is the mask (black and white, white being the leaves), and the bottom image texture is the colour.
It is currently not possible to bake directly to an alpha channel as you mention. 

https://blender.stackexchange.com/a/41904/28015

There are workarounds, though, like you could bake only an emission shader of the masking (in this case you already have the mask so there's no need for that), then make it the alpha channel in the compositor.



Here is the blend:



Just bake the texture, update the compositor, and finally, go the the viewer node in the uv editor.