Ambient occlusion in abstract renderings

While ambient occlusion can greatly enhance the realism of a rendering, it is also very useful in producing abstract, sketch-like illustrations. For example, it is possible to create an architectural drawing that appears to be pencil rendered. In such an image all the surfaces are colored white and only shadows and shading is used to articulate forms and spaces. Without ambient occlusion, these white surfaces would all blend together and reveal little or no detail, as shown in Figure 1.5.11(a). The material used on all objects has a pure white color and the default Matte reflection shader. To make all surfaces appear bright, Ambient Light is increased to 80%. Ambient Occlusion is turned on with 100% Contrast and 30% Additional Contrast to give a more dramatic occlusion effect. Finally the Add Noise option is turned on. This causes ambient occlusion to produce a subtle stipple pattern, which enhances the hand drawn look of the rendering, as shown in Figure 1.5.11(b).