This page provides information about the Generic material in V-Ray for Rhino.
Overview
Generic is a special V-Ray material, that allows for better physically correct illumination (energy distribution) in the scene, faster rendering, more convenient reflection and refraction parameters. Within this material you can apply different texture maps, control the reflections and refractions, add bump and displacement maps, force direct GI calculations, and choose the BRDF for the material.
UI Options
The Generic material settings are organized in Basic and Advanced modes. You can switch the mode from the toggle button under the Preview Swatch or globally from the Configuration rollout of the Settings tab.
An Add Layer button is provided for some V-Ray materials, including Generic. You can select an additional layer that can add up to the appearance of the material. For more information, see the Layers section on Materials page.
From the Add Attribute button, you can select additional attributes that can add up to the appearance of the material. For more information, see the Attributes section.
The context menu of the Color slot provides options to Copy and Paste, as well as to Reset the color.
A Reset option is provided in the context menu of each Number Slider. You can reset the slider value to the default one.
V-Ray Mtl
Diffuse
Some options are available only in Advanced mode.
Color – Specifies the color of the material. For dielectric materials this is the diffuse color. For metals this is the specular reflections color.
Diffuse Roughness – Controls the Diffuse BRDF Falloff. It can be used to simulate rough surfaces or surfaces covered with dust (for example, skin or the surface of the moon). Note that this parameter only affects the diffuse portion of non-metallic materials. For more information, please see the Roughness Parameter example below.
Example: The Roughness Parameter
This example demonstrates the effect of the Roughness parameter. Note how, as the Roughness increases, the materials appears more "flat" and dusty.
Reflection
Some options are available only in Advanced mode.
Reflection – Enables reflection of the material.
Reflection Color – Specifies the reflection color. Note that the reflection color dims the diffuse surface color based on the Energy preservation option. For more information, please see the Reflection Color Parameter example below.
Reflection Glossiness – Available when the Surface control option is set to Use Glossiness. Specifies the sharpness of reflections. A value of 1.0 means perfect mirror-like reflection; lower values produce blurry or glossy reflections. Use the Subdivs parameter below to control the quality of glossy reflections. For more information, please see the Reflection Glossiness Parameter example below.
Reflection Roughness – Available when the Surface control option is set to Use Roughness. Specifies the sharpness of reflections. A value of 0.0 means perfect mirror-like reflection; higher values produce blurry or glossy reflections. Use the Subdivs parameter below to control the quality of glossy reflections.
Fresnel – When enabled, the reflection strength depends on the viewing angle of the surface. Some materials in nature (e.g. glass, etc.) reflect light in this manner. Note that the Fresnel effect depends on the index of refraction as well. For more information, please see the Fresnel Option example below.
Reflection IOR – When disabled, the Refraction IOR is used as Reflection IOR. Enable for finer control over the Reflection IOR.
Metalness – Controls the reflection model of the material from dielectric (metalness 0.0) to metallic (metalness 1.0). Note that any intermediate value between 0.0 and 1.0 does not correspond to a physical material. This parameter can be used with PBR setups coming from other applications. The Metalness texture map should be considered a mask between two different types of materials: dielectric or conductive.
GTR Tail Falloff – Active only when the BRDF is set to GGX. It allows fine tuning of the specular reflections by controlling the rate at which the sharp specular highlight fades out. Higher values create a value spread out the fade out of the highlight. This parameter does not affect the size of the actual highlight - this is controlled by the Reflect glossiness parameter. For more information, please see the GTR tail falloff example below.
Surface Control – Changes the behavior of all material parameters controlling the surface smoothness:
Use Glossiness – The base and coat reflection layers as well as the Sheen will use Glossiness values. A value of 1.0 means perfectly smooth surface, while a value of 0.0. means rough/diffuse-like reflection.
Use Roughness – The base and coat reflection layers as well as the Sheen will use Roughness values. A value of 1.0 means rough/diffuse-like reflection, while a value of 0.0. means perfectly smooth surface.
BRDF – Determines the type of BRDF (the shape of the highlight). There are 4 types available - Phong, Blinn, Ward, Microfacet GTR (GGX). For more information, please see the BRDF Type example below.
GGX is the most modern and flexible BRDF (Bidirectional reflectance distribution function) type and is able to better represent a broad range of materials thanks to its ability to control the shape of the specular lobe. There currently isn't any particular performance difference between models and there is little reason to choose any of the other types.
Back Side Reflect – When disabled, reflections are calculated for the front side of the objects only. When enabled back-side reflections are also calculated.
Max depth – Specifies the number of times a ray can be reflected. Scenes with lots of reflective and refractive surfaces may require higher values to look right.
Affect Channels – Specify which channels are affected by the reflectivity of the material.
Color Only – The reflectivity of the material affects only the RGB channel of the final render
Color+Alpha – Causes the material to transmit the alpha of the reflected objects instead of displaying an opaque alpha.
All Channels – The reflectivity of the material affects all channels and render elements.
Trace Reflections – Enables reflection tracing for the current material. If disabled, disables only reflections and not specular highlights.
Example: BRDF Type
This example demonstrates the differences between the BRDFs available in V-Ray.
Example: GTR Tail Falloff
This example demonstrates the effect of the GTR tail falloff parameter.
Anisotropy
Anisotropy (-1 to 1) – Determines the shape of the highlight. A value of 0.0 means isotropic highlights. Negative and positive values simulate brushed surfaces. For more information, please see the Anisotropy example below.
Rotation – Determines the orientations of the anisotropic effect in a float value between 0 and 1 (where 0 is 0 degrees and 1 is 360 degrees). For more information, see the Rotation example below.
Derivation – Determines the anisotropy orientation method.
Local Axis – The orientation of the anisotropic reflection/highlight is based on the object's local X, Y or Z axis.
Map Channel – When enabled, the orientation of the anisotropic reflection/highlight is based on the specified map channel/set.
Local Axis – Specifies a local axis used for Anisotropy orientation. (X, Y, Z)
Map Channel/Set – Specifies a map channel that is used for the anisotropic reflections/highlights orientation.
Example: The Anisotropy and Rotation Parameters
This example demonstrates the effect of the Anisotropy and Rotation parameters, which determines the shape of the highlight. For the examples below the Type was set to Microfacet GTR (GGX).
Dim Distance
Dim Distance – Enables Dim Distance.
Distance – Specifies a distance after which the reflection rays are not traced.
Dim Falloff – Sets a fall off radius for the dim distance.
Example: The Reflection Color Parameter
This example demonstrates how the Reflection color parameter controls the reflectivity of the material. Note that this color also acts as a filter for the diffuse color.
Example: The Reflection Glossiness Parameter
This example demonstrates how the Reflection glossiness parameter controls the highlights and reflection blurriness of the material.
Example: The Fresnel Option
This example demonstrates the effect of the Fresnel option. Note how the strength of the reflection varies with the IOR of the material. For this example, the Reflection color is pure white (255, 255, 255).
Refraction
Some options are available only in Advanced mode.
Refraction – Enables Refraction of the material.
Refraction Color – Specifies the refraction color. Note that the actual refraction color depends on the reflection color as well. See the Energy preservation parameter below. For more information about refraction color, please see the Refraction Color Parameter example below.
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 the Fog Units Scaling is enabled. The fog color also determines the look of the object when using fog scattering. For more information, please see the Fog Color Parameter and Fog Multiplier Parameter examples below.
Fog Multiplier – Smaller values reduce the effect of the fog, making the material more transparent. Larger values increase the fog effect, making the material more opaque.
Fog Bias – Changes the way the fog color is applied. Negative values make the thin parts of the objects more transparent and the thicker parts more opaque and vice-versa (positive numbers make thinner parts more opaque and thicker parts more transparent).
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 does not change direction. For more information, please see the Refraction IOR Parameter example below.
Refraction Glossiness – Specifies the sharpness of refractions. A value of 1.0 produces perfect glass-like refraction; lower values produce blurry or glossy refractions. Use the Subdivs parameter below to control the quality of glossy refractions. For more information, please see the Refraction Glossiness Parameter example below.
Affect shadows – When enabled, the material casts transparent shadows, depending on the refraction color and the fog color. This only works with V-Ray shadows and lights.
Fog Units Scaling – When enabled, the fog color attenuation becomes dependent on the current system units.
Max depth – Specifies the number of times a ray can be refracted. Scenes with lots of refractive and reflective surfaces may require higher values to look right.
Affect Cchannels – Specifies which channels are affected by the transparency of the material.
Color Only – The transparency of the material affects only the RGB channel of the final render.
Color+alpha – Causes the material to transmit the alpha of the refracted objects instead of displaying an opaque alpha. Note that currently this works only with clear (non-glossy) refractions.
All channels – The transparency of the material affects all channels and render elements.
Trace Refractions – Enables/disables refraction tracing for the current material. The option disables only the refraction and not the transparent shadows. To make the shadows opaque, disable the Affect Shadows checkbox or set the Refraction Color to black.
Dispersion
Dispersion – When enabled, true light wavelength dispersion is calculated. For more information, please see the Dispersion example below.
Abbe – Increases or decreases the dispersion effect. Lowering it widens the dispersion and vice versa.
Fog Scattering
Fog Scattering2 – Enables fog scattering.
Type – Selects the algorithm for calculating fog scattering (also called sub-surface scattering). Note that Refraction must be enabled and the refraction fog color should be different from white for this effect to be visible.
Hard (wax) model – This model is specifically suitable for hard materials like marble.
Hybrid – This is the most realistic SSS model and is suitable for simulating skin, milk, fruit, juice, etc.
Back-side Color – Normally the color of the subsurface scattering effect depends on the Fog color. This parameter allows you to additionally tint the SSS effect.
Scatter Coeff – The amount of scattering inside the object. 0.0 means rays are scattered in all directions; 1.0 means a ray cannot change its direction inside the sub-surface volume.
Fwd/back Coeff – Controls the direction of scattering for a ray. 0.0 means a ray can only go forward (away from the surface, inside the object); 0.5 means that a ray has an equal chance of going forward or backward; 1.0 means a ray is scattered backward (towards the surface, to the outside of the object).
Thickness – Limits the rays that are traced below the surface. This is useful if you do not want or don't need to trace the whole sub-surface volume.
Light Multiplier – Multiplies the translucent effect.
Example: The Refraction Color Parameter
This example demonstrates the effect of the Refraction color parameter to produce glass materials. The material has a gray Diffuse color, white Reflection color, and the Fresnel option is turned on.
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.
Example: The Fog Multiplier Parameter
This example demonstrates the effect of the Fog multiplier parameter. Smaller values cause less light absorption because of the fog; while higher values increase the absorption effect.
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.
Example: The Refraction Glossiness Parameter
This example demonstrates the effect of the Refraction glossiness parameter. Note how lower Refraction glossiness values blur the refractions and cause the material to appear as frosted glass.
Example: The Refraction Depth Parameter
This example shows the effect of the Refraction depth parameter. Note how too low of a refraction depth produces incorrect results and areas with total internal reflection are also affected by the Reflection depth.
Example: Dispersion
This example demonstrates the Dispersion capabilities of the V-Ray material and the effect of the Abbe parameter.
Coat
Available only in Advanced mode.
Coat Amount – Specifies the blending weight of the coat layer. A value of 0 does not add a coat layer, while higher values blend the coat gradually.
Coat Color – Determines the coat layer's color. A texture map can be used here.
Coat Glossiness – Available when the Surface control option is set to Use Glossiness. Controls the sharpness of reflection. A value of 1.0 means perfect glass-like reflection; lower values produce blurry or glossy reflections. See the Coat Glossiness example below.
Coat Roughness – Available when the Surface control option is set to Use Roughness. Controls the sharpness of reflection. A value of 0.0 means perfect glass-like reflection; higher values produce blurry or glossy reflections.
Coat IOR – Specifies the Index of Refraction for the coat layer.
Coat Bump
Available only in Advanced mode.
Mode / Map – Allows the user to specify whether a bump map or a normal map effect is added to the base material.
Bump Map – Requires a height map.
Bump Texture Channel – Most commonly used for the Round Edges effect (Edges texture used as bump).
Normal Map – Requires an RGB map. If a Bitmap texture is slotted, its color space must be set to Rendering Space (Linear).
Amount – Multiplies the Bump / Normal effect. See the Coat Amount example below.
Example: Coat Amount
This example shows how the Amount value affects the look of the material. The base Reflection Glossiness is set to 0.76 and the Coat Glossiness is set to 1. The value of the Coat IOR is set to 2 and the Coat Color is the default white.
Example: Coat Glossiness
Coat Glossiness controls the sharpness of the coat reflection. Here, the base Reflection Glossiness is 0.76 and the Coat Amount is 1. Coat IOR is 2 and the Coat Color is the default white. Notice how higher values produce glossier reflection and lower values make it look blurry.
Sheen
Available only in Advanced mode.
Sheen Color – Specifies the color of the sheen layer. Black color disables the effect.
Sheen Glossiness – Available when the Surface control option is set to Use Glossiness. Controls the sharpness of reflection. A value of 1.0 means all of the light reaches the diffuse color, and when the value is smaller, the cloth material looks glossier. See the Sheen Glossiness example below.
Sheen Roughness– Available when the Surface control option is set to Use Roughness. Controls the sharpness of reflection. A value of 0.0 means all of the light reaches the diffuse color, whereas when the value is higher, the cloth material looks glossier.
Example: Sheen Glossiness
This example shows how changing the glossiness parameter of the sheen layer affects the material. A smaller value makes the sheen layer reflect most of the light. Increasing the value allows more light to reach the diffuse component.
Opacity
Some options are available only in Advanced mode.
Opacity – Specifies how opaque or transparent the material is. A texture map can be assigned to this channel.
Custom Source – When enabled, V-Ray uses an alpha channel to control the material opacity.
Diffuse Texture Alpha – The diffuse texture alpha channel controls the opacity. Diffuse Texture Alpha source works the same way as Diffuse Map Alpha as Transparency legacy option from the V-Ray versions before 3.60.
Opacity Texture Alpha – The opacity texture alpha channel controls the opacity, instead of the default texture intensity. If there is no texture in the source slot, the option is ignored.
Mode – Controls how opacity is sampled.
Clip – (Very fast) The surface is shaded as either fully opaque or fully transparent depending on the value of the opacity map (i.e. without any randomness). This mode also disables the filtering of the opacity texture. This is the fastest mode but it may increase flickering when rendering animations.
Stochastic – (Optimal) The surface is randomly shaded as either fully opaque or fully transparent so that on average it appears to be with the correct transparency. This mode reduces lightning calculations but might introduce some noise in areas where the opacity map has gray-scale values. The opacity texture is still filtered as normal.
Bump
Bump – Enables or disables the bump or normal effect.
Mode/Map – Specifies the bump map type.
Bump Map – A height map should be used.
Normal Map – RGB map should be used with this option. Note that in most cases the normal map bitmap color space should be set to Linear to ensure correct results.
Amount – Multiplier for the bump/normal effect.
Multipliers
Mode – Specifies how textures and colors will be blended by the multipliers.
Multiply – The texture is blended with a black color.
Blend Amount – The user-specified color is used for blending
Color – Controls the intensity of the Diffuse color.
Reflection Color – Controls the intensity of the reflection color.
Reflection Glossiness – Controls the intensity of the reflection sharpness.
Refraction Color – Controls the intensity of the refraction color.
IOR – Controls the intensity of the Index of Refraction value when calculating refraction.
Refraction Glossiness – Controls the intensity of the refraction sharpness.
Opacity – Controls the intensity of the overall material Opacity.
Binding
Texture – Selected textures are displayed in the viewport. Keep in mind that procedural texture will not get displayed. Note that the viewport texture will not affect the way the material is rendered in V-Ray. It is mainly used for preview purposes.
Override Control
Can be Overridden – When enabled, the material can be overridden by the Material Override option in the Settings.
Attributes
The attributes from the following expandable menus are available for the Generic material.
Notes
Materials with Normal opacity mode are now migrated to Stochastic opacity mode.
The Highlight Glossiness parameter is a legacy plugin. It is migrated from previous versions; however, if it is disabled, the row is hidden and its value is set to 1.
Use the VRayMtl/VRayBRDF whenever possible in your scenes. This material is specifically optimized for V-Ray and often GI and lighting is computed much faster for V-Ray materials than for standard materials. Many V-Ray features (e.g. light cache, render elements ) are guaranteed to work properly only with VRayMtl and other V-Ray compliant materials.
VRayMtl can produce reflections/refractions for matte objects - see Wrapper.
The 2D mapping method will ignore the Tiling parameters specified in the textures themselves.
- Having a very large number of scene objects using materials with 2D Displacement may substantially prolong the geometry compilation phase of the rendering process.
Prior to V-Ray Next, Update 1 the Fog Scattering section was known as Translucency.