Refraction – Specifies the refraction color. Note that the actual refraction color depends on the reflection color as well.
Fog color – Specifies the attenuation of light as it passes through the material. This option allows to simulate the fact that thick objects look less transparent than thin objects. Note that the effect of the fog color depends on the absolute size of the objects and is therefore scene-dependent unless Fog system units scaling is enabled in the advanced settings. The fog color also determines the look of the object when using translucency. For more information, please see the Fog Color Parameter example below.
Fog Multiplier – Multiplies the strength of the fog effect. Smaller values reduce the effect of the fog, making the material more transparent. Larger values increase the effect of the fog, making the material more opaque.
Refraction Glossiness – Controls the sharpness of the refraction. A value of 1.0 means a perfect glass-like refraction. Lower values produce blurry or glossy refractions.
IOR – Specifies the index of refraction for the material, which describes the way light bends when crossing the material surface. A value of 1.0 means the light will not change direction. For more information, please see the Refraction IOR Parameter example below.
Bump – Specifies a bump/normal map and controls its intensity.
Example: The Fog Color Parameter
This example demonstrates the effect of the Fog color parameter. Notice how the thick areas of the object are darker in the two images on the right because of the light absorption of the fog.
Fog color = White
(255, 255, 255)
no light absorption
Fog color = Gray
(243, 243, 243)
Fog color = Green
(230, 243, 213)
Example: The Refraction IOR Parameter
This example demonstrates the effect of the Refraction IOR parameter. Note how light bends more as the IOR deviates from 1.0. When the index of refraction (IOR) is 1.0, the render produces a transparent object. Note however, that in the case of transparent objects, it might be better to assign an opacity map to the material, rather than use refraction.
IOR = 0.8
IOR = 1.0
IOR = 1.3
IOR = 1.8