Hi Kent. At the end of the video "Baking a Normal Map" you saved the N_bake.png file with the Alpha channel (RGBA). However in other videos you just go with RGB (without any transparency). How do we know when to select RGB or RGBA? Thanks!
The short answer: You only need to use an alpha channel if you need transparency in your image.
So in this course I bake out each rock's maps individually. But in this lesson - https://cgcookie.com/lesson/consolidation-export/ - you'll see how I consolidate all the individual maps into one master Normal, one master Color, etc. Having the alpha channel on each individual bake made it easy to combine them all together over an appropriate color background. Then I saved out the final version of each texture without an Alpha since the rocks aren't transparent at all.
