NEW IN R20
Comparable with the modes of the Reflectance channel in a physical material, you can define a diffuse, shiny or anisotropic distorted reflection. Since multiple BSDF Nodes can be layered within a given material, a physical material setup with a diffuse BSDF layer as a basis, followed, for example, by a reflective Beckmann BSDF layer can be created:
The Diffuse BSDF calculates a maximum rough reflection that includes all brightness in the surrounding environment and is used for the shading on the surface. These extremely dispersed reflections are multiplied with the Color value and produce the shaded surface. Since these not only react to light sources but also to indirect illumination from within the scene, no additional Global Illumination calculation is required to simulate natural lighting effects. The Diffuse BSDF Type therefore creates the basis for a shaded surface and displays the color.
Here you can define the diffuse surface color or the coloring of the reflections on a surface. Note that dark colors will reduce the intensity of the reflections correspondingly.
This is a multiplier for the brightness of the BSDF layer. Values in excess of 100% can possibly make the surface appear brighter than it normally would and prevents the material from applying proper rules of energy conservation. Physically correct, therefore, is only the use of an Intensity value higher than 0% and lower or equal 100%. Values of less than 100% will darken the surface further, e.g., to simulate a dirty surface.
Use this setting to control. how much the microfacet normals will differ from the smoothed surface geometry. A Roughness of 0% represents a perfectly smooth surface as you might have on a real-world mirror or freshly chromed surface. Higher values will lead to a dispersion of reflection rays and therewith to an increasing blurring of the reflection. If the BSDF Type is set to Diffuse, a maximum roughness will automatically be used, even if Roughness is set to 0%. The dispersion can, however, also be affected in Diffuse by increasing the Roughness value, which will simulate a diffuse Oren-Nayer shading. A Roughness value of 0% if BSDF Type is set to Diffuse will then correspond to a Lambert (Diffuse) mode, whereas a Roughness value in excess of 0% will calculate a correspondingly larger Oren-Nayer shading, as is also possible using the Reflectance setting in a physical material.
This setting is only available if BSDF Type is set to Anisotropic. It defines the strength of the distortion in the reflection. The direction of the distortion can be defined using the separate Direction setting.
This setting is only available if BSDF Type is set to Anisotropic. It defines the direction in which the simulated scratches run on the surface. The distortion of the specular lights or reflections will automatically follow the direction of these scratches.
This setting defines the number of reflection rays that are used for the BSDF layer’s roughness. However, this value will only be evaluated if the Standard Renderer is used. The Physical Renderer’s. blurry reflectivity has its own setting Blurriness Subdivision (Max).
Here you can, for example, link a Normal map or bump map to affect the surface’s shading.
This setting can be used to define the intensity with which the reflection and shading calculation will be affected by the input Normals.
The Fresnel effect defines the intensity of the reflection depending on the angle of view onto the surface. Two default groups are available for Conductor and Dielectric materials. Conducting materials are, as a rule, metals such as gold, silver or aluminum and can be selected directly from the Presets menu. Dielectric materials on the other hand are partially opaque, e.g., glass or water.
As a rule, the Fresnel effect reduces the intensity of the reflection at locations at which the surface is viewed perpendicularly. Reducing the Fresnel Strength can make the intensity of the reflection more homogenous and the Fresnel effect can be blended freely. However, you should be aware of the fact that this deviates from the physically correct behavior, at least if you’ve already selected the material you want to display via the Fresnel and Presets menu.
These are the refraction values for red, green and blue if Fresnel is set to Conductor. The coloring of the surface and its reflection is defined depending on the angle from which it is viewed.
If Fresnel is set to Conductor, this setting can be used to affect the intensity of the reflection separately from the three color portions of the reflected light.
Defines the index of refraction if Fresnel is set to Dielectric. Larger values will produce correspondingly more reflection.
A dielectric BSDF with appropriate Fresnel settings will by default transfer some light to the underlying BSDF layers (if any) and therefore appear semi-transparent. To avoid this, enable the Opaque switch.