How to mix 3 normal maps?

[ldotchopz]

the composite node doesn’t quite bring them through at their full strength and vray comp tex doen’s either and is limited to 2 slots for some reason. In Redshift they have a bump blender that allows many inputs both bump and normal. what is the correct way to do it in V-ray?

[fixeighted]

This method seems to work just fine. Looking at each map individually the composite is keeping the relative strengths intact, though
of course you can boost the contribution of each also.

[Vizioen]

You can also use nested VrayBPMMaterials. Like so: