Different map types

somefunok

I was hoping that someone could please explain the different types of maps that come with products and what exactly each map does, for example:

Normal, Bump, Displacement, Specular, Roughness etc?

Richard Haseltine

Normal and bump both chnage the way a surface takes the light, normal by explicitly saying this bit faces in thsi direction and bump by saying this section is raised/lowered by so much. Neither actually chnages the shape. Displacement is like bump in that it specifies elevation, but it actually moves the mesh (in Iray it needs a vertex to move, in 3Delight it can work without needing vertices).

Specular and roughness both relate to shininess - roughness says how rough a surface is, specular may be used in several ways - to set the shininess (inversely to roughness), to set the strength of the shine (how visible the hohglights are), or to set the colour of the highlights.

somefunok

Thank you for that explanation but can you please expand a bit more on what you mean by "Normal explicitly says this bit face in this direction" as that still has me confused as to what a Normal map does?

Richard Haseltine

A normal map's colour values (the red, green, and blue) are treated as a unit vector [ r , g , b ] giving the direction of the shader nomral (the direction the surface is lit as if facing) relative to the real facing of the surface. Some application treat [ x , y, z ] as a direction ins pace, rather than a direction relative to the surface normal - you can see the difference as those maps shift colour across the surface, while the relative maps are uniform over the surface with (usually) minor varitaions.