Posts Tagged ‘Kajiya and Kay’

Adding common lighting effects

  • Blinn-Phong shading model

The methods presented so far give only information about shadows cast by translucent objects on themselves.  In a Blinn-Phong shading model this would correspond to the diffuse lighting, but the specular and the ambient lighting have to be added as well. These two terms were used as described in the Blinn-Phong model (Figure 1), although for the specular component more advanced techniques such as Kajiya and Kay or Marschner could be used when rendering hair.

Figure 1 Picture from Crystal Space. Scene rendered without any specular or ambient lighting (a) and scene rendered using these two terms as described in the Blinn-Phong model (b).

  • Shadow mapping

Opaque objects were introduced in the scene by using the depth map that computes the initial splitting positions. This map is actually a regular shadow map, so adding opaque objects to the scene was just a matter of applying a common shadow mapping algorithm without any additional computational costs (Figure 2).

Figure 2 Picture from Crystal Space. Opaque objects don’t cast shadows (a) and cast shadows using shadow mapping (b).