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royter
09-03-2007, 08:25 PM
if u load the ceramic perset in the mia_material,
the refraction index has a huge impact on the reflectivity of the material even if transparency is off.

isn't this weird? because the refraction index is directly related to transparency, so if it is off then refraction index shoudn't have any effect.

Kako
09-03-2007, 10:32 PM
Hi royterr.
That's because of the Fresnel reflectance.
For smooth surfaces, the amount of reflected light is given by the Fresnel equations, which depend directly on the index of refraction of the materials.
So you have this kind of behavior when the Fresnel option is checked under the BRDF options of the mia_materia.

Kako.

royter
09-03-2007, 10:35 PM
Hi royterr.
That's because of the Fresnel reflectance.
For smooth surfaces, the amount of reflected light is given by the Fresnel equations, which depend directly on the index of refraction of the materials.
So you have this kind of behavior when the Fresnel option is checked under the BRDF options of the mia_materia.

Kako.

thanks Kako
so it is related to fresnel, i get it.

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