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It's a fine tutorial, but it doesn't explain enough. In fact, it is quite confusing. Your tutorial tells how to set the masking and what it can do, but it doesn't explain in good detail how this works. It would be more helpful if you explained why doing all of this will create the effect. People will wonder if any AS is needed or why not just use AS as opposed to setting up layers like you did. I would assume that the "Flashlight" layer would need AS so it can move or follow user commands or something, but none of that is explained when it really should be. Because of this, alot of people will be confused about what you are explaining here. You need to do a better job at explaining the information for your tutorial to be read right.