After watching This Cody Gindy video (https://www.youtube.com/watch?v=s8N00rjil_4&t=268s) I knew I had to use the effect on my characters. Problem is, after hours of hand painting an object space normal map, I learned the lighting doesn’t work right on a rigged character and it needs to be in tangent space (the issue can be seen on the character’s arm) I don’t think I can handpaint it in tangent space. Is there a way to convert it? and will it keep it’s painterly effect?
He mentions on the video that you need to convert to tangent. You can do that baking a tangent normal map from the original pose with the object space map you made. As for painting tangent, that will be very hard trying to simulate flat surfaces painting on a tangent map in a round object. A better solution is to sculpt on the high poly mesh (use a flatten brush for instance) and then baking from the sculpted to the original mesh. Like a standard high poly sculpt to low poly bake. You’ll find many tutorials on both options.
On the resulting tangent map, you could also distort the image with brushes or filters and get it more painted like.
By the way you don’t need substance for anything he showed. Not sure why people use it since it’s a lot less capable. You can do all that in Blender.