Texture build-up example: Concrete road

This is an additional example for my article on textures. It is an example of the build-up of a concrete road material.

1. Glossiness map

A Glossiness map is roughly the inversion of a Roughness map. It determines how sharp or blurry reflections of the material are.

It is a grayscale texture with perfect black representing parts that are matt reflecting, and perfect white parts that are sharp reflecting. All the grayscale values between black and white give a reflection sharpness that goes up linearly in-between.

2. Bump map

Bump maps are similar to Normal maps. They fake surface detail such as bumps, grooves, and scratches without having to model the actual surface details. This keeps the model light and keeps render times low.

A Bump map in contrast to a Normal map is a grayscale texture and the render software interprets the white color in the texture as the normal smooth surface. Everything gray up to black is interpreted as being added depth relief into the surface. A black line would therefore be interpreted as a scratch on the surface and it would catch shadow and highlights through the lighting in the scene when rendered.

3. Normal map

A Normal map does more or less the same as a bump map. They fake surface detail such as bumps, grooves, and scratches without having to model the actual surface details. Either a Bump or a Normal map is normally used. With a (personal) preference towards the normal map. As these tend to give better results.

In a Normal map the direction of the relief of the objects surface is captured in an RGB (Red, Green and Blue) color scheme. Each color represents a different axis of direction. The render software can interpret the different RGB hues and can fake relief by adding shadows and highlights. A concrete road material has a lot of relief, and you can see this clearly in the Normal map texture. Normal maps most often have a purplish base color with variations of red, green and blue indicating surface directions of the relief. You can clearly see the relief of the road captured in the texture

4. Displacement map

A Displacement map is something you can consider a really heavy weapon. As Bump and Normal maps fake surface relief, a Displacement map is used to actually create the surface geometry during rendering. 3D software have displacement techniques that basically break down your polygon object(s) into many, many, many really small triangular polygons (often far into the millions of polygons). And the Displacement texture is than used to actually displace your object surface.

A Displacement map is a grayscale texture and the render software interprets the black color in the texture as the base surface height. Everything gray up to white is interpreted as being added relief on top of the surface.

5. Color map

The Color map contains nothing more than all the colors for a material. If you have for example a paint texture, it is the color map that determines the color of the paint. For the concrete road, the color is primarily a gray tone.

That concludes the build- up of this concrete road material.

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