With a bump map, we showed in the Add depth to a mesh with a bump map recipe, how to add depth and detail to a mesh using a specific texture. In this recipe, we provide another way to add even more depth and details without increasing the vertex count of the geometry. To do this, we will use a normal map. A normal map describes the normal vector for each pixel, which should be used to calculate how light affects the material used in the geometry.
To use normal maps, we first need to get a color map and a normal map. For this recipe, we've used two screenshots. The first is the color map:
The next screenshot is the normal map:
Now that we've got the two images, let's first look at how this would look in practice. To see a normal map in action, open the 04.02-add-depth-to-mesh-with-normal-map.html example:
In this example, you can see a standard rendered cube on the left-hand side and one where a normal map is added to on the right-hand side...