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Complex Fresnel

Complex Fresnel

by HotPies
Last crawled date: 2 years, 7 months ago
Complex Fresnel Texmap plugin for 3ds Max.Product DescriptionThis Texmap plugin can be used to render materials with complex index of refraction (IOR): the regular material (for example V-Ray, Corona Renderer) can compute the Fresnel effect for dielectric materials like plastic based on the IOR of the material (n) – however metals have a more complicated Fresnel reflective curve that depends also on another parameter called extinction (k) coefficient: η = n + ik.n and k determine the two characteristics of the Fresnel curve for a material: the reflectivity at normal incidence and how quickly it fades to white at grazing angles.The Texmap plugin can be used as a reflection color map in a material with the Fresnel option of the material turned off (this plugin does its own Fresnel calculations).PARAMETERSn– the n (IOR) values for the Red/Green/Blue wavelengths (0.650, 0.510 and 0.475 μm).k– the k (Extinction coefficient) values for the Red/Green/Blue wavelengths.Presets– some presets for quick start (to enter other parameters (n, k) values it is necessary to select preset Custom).If you need a bit different color (f. e. for various alloys), use aColor Adjustmentparameters and adjust the Gamma, Hue, Saturation values. This way you still have the correct Fresnel curve and are just making color changes.Gamma– specifies the gamma correction value.Hue Shift– lets you change colors using a standard Hue spectrum. Range = -180…180.Saturation– the intensity or purity of the colors. Lowering the Saturation value removes color, causing the color to tend toward grayscale, while raising it intensifies the color. Range = -100…100.How to get valuesThe sitehttp://refractiveindex.info/has the measured n and k values for many metals like Copper, Gold, Iron etc. http://www.sigerstudio.eu

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