Game Development Reference
In-Depth Information
two maps. The first is a texture where the bricks of the wall are simply drawn. The
second is a black and white bump map that represents the protrusions and indent-
ations of the bricks composing the wall. Both the maps are included in the material
and then applied to the 3D mesh. The final result is a wall that looks like it is fully
modeled, but instead, it's just a flat parallelepiped with a nice looking material.
The following figure represents a bump map that can be added to the wall material
to make it look more realistic:
To get a better result when using low-poly models, game artists, as we said, use nor-
mal mapping. It is an improvement over simple bump mapping because it creates
a map of how light bounces on the surface of the high-poly model, which is more
detailed, and apply that map to the low-poly model. The main difference between a
bump map and a normal one is that normal maps represent the refraction of light in
the 3D world, because they allow the re-direction of light bouncing on a surface ac-
cording to the orientation of its pixels in the 3D world. Normal mapping is very useful
to fake the details of a high-poly model on a low-poly one, but requires the original
model to get the normal map to be fully detailed (as we said, these high-poly models
are created with sculpting tools like ZBrush or Mudbox).
The following figure represents a normal map to be added to the material of the wall
instead of the bump map:
