Mapas de normales : bump mapping : Mapeado topológico

In computer animation the number of surfaces in the scene greatly influences the time of computation (rendering) de la SMA.

A technique for simulating on a flat surface roughness is called “Bump mapping“; is apply a texture on the surface changes the direction of the normal thereto, influencing the calculation of shading algorithms (Shading) applied during image rendering, without changing the topology.

Topological mapping (English, bump mapping) is a 3D computer graphics technique created by James F. Blinn one 1978. It consists in giving a rough appearance to the surfaces of the objects. This technique modifies the surface normals without changing its geometry. The original normal surface perpendicular thereto will. The topological mapping changes the normal perpendicularity other to achieve the desired effect, not modifying the topology and geometry of the object. (W)

Textura for bump mapping

Left without bump mapping, right with bump mapping

In the following video shows two surfaces. On the left, plane has been modified to alter its geometry generating some bumps. On the right we used a plane with a texture applied that modifies its normal. The first surface is composed of several thousands of polygons, while the second only by two triangles.

By changing the position of the light we see shadows vary in both cases, but by changing the point of view of the camera shows the significant difference between the two.