How to make clouds

Question

So I saw this pic of clouds in game The Witness and I really liked how they made the clouds. How to reproduce them?

Answer 1

sorry for the previous short and unexplained answer :)

First open up blender and add a plane, then UV unwrap it like below (I've made a very simple cloud texture for that with transparency)

then add a plane so we can actually see something in the test render

then go to rendered shading mode by enabling it from the red icon indicator

notice how the transparency (alpha channel) has been filled with black?

its because of the default material setup as shown in the picture below! the diffuse shader can't render transparency

its only using a diffuse shader with a image with transparency

now, if we add a transparent shader with mix shader node and the alpha from original image as the fac value then we will get something like below

its basically checking weather a part of the texture is transparent and if so it is feeding it through the transparent shader so we can get the actual transparency..... and the rest is going through the diffuse shader

by this method you can get the cloud you were referring to.....

now, you might wanna import image as a plane (check if the addon is enabled) then apply this method, but for some wired reason (I don't know why) its not working in my blender 2.74... hope somebody can lighten me up :)