Textures for Visualization - 3D for Graphic Designers - page 216

64). This render represents a 50% increase in render time as opposed to the previous render, and the number
of rays could still be increased to achieve a result similar to that of the previous setting.
Figure 6-42: A small amount of Refraction Roughness (10%) adds a slight fogged look to the material.
Figure 6-43: Higher roughness values require more refraction rays and increase render time significantly.