18.104.22.168 Conserve Energy for Reflection
One of the features in POV-Ray is variable reflection, including realistic Fresnel reflection (see section "Variable
Reflection "). Unfortunately, when this is coupled with constant transmittance, the texture can look
unrealistic. This unrealism is caused by the scene breaking the law of conservation of energy. As the amount of light
reflected changes, the amount of light transmitted should also change (in a give-and-take relationship).
This can be achieved by adding the
conserve_energy keyword to the object's
conserve_energy is enabled, POV-Ray will multiply the amount filtered and transmitted by what is left over from
reflection (for example, if reflection is 80%, filter/transmit will be multiplied by 20%).