fill
Shades area near ground and concave angles between walls where the radius defines only vertical impact. Default value 3.0 corresponds to height of one floor and brings the most plausible results for buildings. This property works only with legacy light. When 3D lights are enabled fill-extrusion-ambient-occlusion-wall-radius and fill-extrusion-ambient-occlusion-ground-radius are used instead. Default value: 3. Minimum value: 0.