6.2.6 Refraction

When light passes through an object (having non-zero transmit or filter parameter) of different density then the surrounding air the light is bended. This is called refraction. By default transparent objects in Pov-Ray do not refract light. But this can be turned on by

	finish { ... refraction 1 ior K ... }

where K is the i(ndex)o(f)r(refraction). Water has an ior of 1.33, glass of approximately 1.5 and diamond of 2.4 (see "ior.inc").