Displacement and normal map

i’m quite a bit confused by these two kind of maps. i see over the internet that people sometimes use them both…but the question is, if a displacement map uses black and white values to create geometry on to a surface, why would i need to use a normal map with a displacement version of it? i’m talking about surfaces like brick walkways or “flat surfaces” made of bumpy materials…and, once again, i’m only asking because i see people using them simultaneously.

A displacement map controls how far various parts of the geometry are physically moved in or out from the surface. A normal map controls which way and how much the various faces are rotated compared to the base surface. In other words, a normal map controls which way the surface normals point.

Also, normal maps fake it while displacement maps actually change the location(s) of faces.

normal maps are harder to generate, but can be much more detailed. bump(displace) maps are more for displacing geometry (landscapes) or for subtle details that dont need the complexity of normal maps.

many times, bump maps and diffuse/glossy can be shared, making this a easy way to add a touch of detail.

normal maps are required if you are hires to lowres baking, and then a bump map could be use to rough it up some more.

Anyone have a node setup to convert a displacement map to a normal map?

Simply take the displacement through a Vector/Bump node.