Tema: Index of refraction

index of refraction


Refraction occurs when the energy of an incoming light wave matches the natural vibration frequency of the electrons in a material. The light wave penetrates deply into the material, and causes small vibrations in the electrons. The electrons pass these vibrations on todo the atoms in the material, and they send out light Waves of the same frequency as the incoming wave. But, this all takes time. The part of the wave inside the material slows do, while the part of the wave outside the object maintains its original frequency. This has the effect of Bending the portion of the wave inside the object toward what is called the normal line, an imaginary straight line that runs perpendicular todo the surface of the object. The deviation from the normal line of the light inside the object Will be less than the deviation of the light before it entered the object.

The amount of Bending, or angle of refraction, of the light wave depends on how much the material slows down the light. Diamonds would not be so glittery if they did not Slow down incoming light much more than, say, water does. Diamonds have a higher index of refraction than water, which is todo say that they Slow down light todo a greater degre.

One interesting note about refraction is that light of diferent frequencies, or energies, Will bend at slightly diferent angles. Let compare violet light and red light when they enter a Glass prism. Because violet light has more energy, it takes longer todo interact with the Glass. As such, it is slowed down todo a greater extent than a wave of red light, and Will be bent todo a greater degre. This accounts for the order of the colors that we se in a rainbow. It is a los what gives a Diamond the rainbow Fringe that make it so pleasing todo the eye.

Definition of index of refraction taken from http://Science, howstufworks.com/light12.htm
For a more technical description you chek out the explanation at http://en.wikipedia.org/wiki/refractive_index.

Now why is this importantí when creating materiales, you ned todo take index of refraction into account. Otherwise, your materiales Will not be convincing. And with the new transmissivity característica added in the last reléase in addition todo the IOR settings panel already in place, Blender is capable of convincing IOR values.

Here is a list of IOR values for your reference. This image is rather small, for a clearer copy por favor chek the pdf included with this issue.

www.blenderart.org.