Hi I made a new modifier enabling normals manipulation, it takes vertex colours and converts them to normals:
Usual vertex normals:
Modified vertex normals:
Folowing formulas are used for conversion of RGB to XYZ of normal:
x = r - 0.5
y = g - 0.5
z = b - 0.5
So, for example, if you want normals of some vertices to be pointing up set r = 0.5, g = 0.5 and b = 1 and paint these vertices. Normals will be normalised so any b > 0.5 will work. Also shading has to be set to smooth.
If you paint vertices black or just leave them white their normals will be unchanged.
Any feedback is welcome =)