Typical PBR Maps (Overview)
Here is a short explanation outlining the function of the different material maps included in the materials on ambientCG (and many other websites).
Color
The general color map of the material. Some programs also call it “Albedo”, “Diffuse”, or “Base Color”.
Displacement
It defines the height/displacement of the material. Using this in combination with very-high-poly geometry allows for more detailed surfaces.
Normal
The normal map defines the normal vector of the surface at a given point. It can be used to simulate intricate surface detail without adding any more geometry.
Different tools require slightly different versions of the normal map due to two different implementations in the two graphics libraries OpenGL and DirectX.
Downloads from ambientCG always include a _NormalGL (OpenGL-Style) and _NormalDX (DirectX-Style) file. You can simply try out both versions in your software and check whether the surface responds correctly to light from all angles or look up/ask the vendor's support about the normal format to use.
Below is a table for some common tools:
| Blender | OpenGL (_NormalGL) |
| Unity | OpenGL (_NormalGL) |
| Unreal Engine | DirectX (_NormalDX) |
| Adobe Substance 3D Products | DirectX (_NormalDX) by default, can be changed in settings. |
Ambient Occlusion
Ambient occlusion serves to fake the tiny, soft shadows that the material is throwing onto itself. This causes crevices to be a little bit darker. The ambient occlusion map simply gets multiplied with the color map. Therefore the dark parts of the map also darken the final color map while the white parts leave it untouched.
Roughness
This map describes the roughness of the material. If this image is closer to black that means that the material appears to be very shiny. Consequently an almost white image means that the material has a very diffuse look.
Opacity
A black and white map to define the opacity of the material. White parts remain visible, darker parts become transparent.
Metalness
Defines whether a part of the surface is metallic or dielectric. This changes the way light is reflected and is important for achieving realistic results.
Emission
This map defines the light that a material emits. For most materials this map is just black or not even there.