This is a node tree setup that can be used to combine two normal maps. By default, file opens into a compositor and UV/Image editor, which can be used to combine normal maps and save the result for later use. The file also contains a Cycles node tree that can be used for the same purpose in Cycles materials. Usage instructions are provided in a text block (you'll see it when you open the file, just make sure you have 'Load UI' ticked on).
Note that Blender Internal does that very easily. Simply add multiple textures and set them as normal maps (in both Influence and Image Sampling). You can then tweak each normal's influence and bake.
is there a way to download it from anywhere else? it wont download for me for some reason
Download link is broken. It downloads only html page instead of zip file.
If you get an HTML file then change it from .html to .zip using your explorer and you´re good to go. Or you can open it using Winrar and it will work too.
I really like your node set up. append nodes, work with 2.8 too (though I only test with cycles) thanks much. I can easy add second normal maps without lost base normal map effects. I download it by chrome.
Still gold as today, opened in old 2.79 It is so easy to use with perfect explanations, took me barely 1mn to get the mixed result Thank you sir/miss
Depending on your needs hoop grids, you might use math nodes to perform operations like addition or multiplication on the normal maps. This could be helpful for blending details from each map.
Beautiful! I'm using this in my workflow now. Works wonderfully. Thank you! (and special thank you for making it CC-Zero!)