Parallel-Point lights

Parallel-point lights have only color and position. They create lighting effects similar to point lights but with less overhead, at the cost of some accuracy. As a result, parallel-point lights are often a good choice when extremely accurate specular highlights are not critical. Direct3D illuminates a mesh with a parallel-point light in a manner similar to a point light, but uses a shortcut to increase performance. The shortcut taken is in establishing a single direction for the light hitting all vertices in a mesh, rather than calculating a new direction for each vertex like a point light. (The direction that is used is the vector from the light's position to the origin of the mesh.) Because the light has the same direction for all vertices, it is considered parallel, hence the name. Like directional lights, parallel-point lights are not affected by range or attenuation.