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Specular Layer

For first lets answer the question: What has the specular to do with glossy reflection?

All is the answer specularity is physically seen an unsharp or glossy reflection of an light source or any other light part in the environment of an object, therefore also in vray the specularity is bound to the glossy reflection, VRAY however gives you the possibility to use both: traditional "cheated" specular effects and real physical correct glossy reflections.

The specular color gives the main color of the reflection. a car paint p.e. might be “Ferrari red”, maybe uses also a Fresnel falloff with slight color variation depending on viewangle.
The Specular Layer parameters let you set the glossiness of the specularity (classic fake specular) and the glassy reflection, this can be set via texture, you can set a multiplier for the texture, shader or slider, a value of white or 1 will give a sharp non glossy reflection. a value of 0.8 will give a 80% glossiness (equals 20% roughness), you can adjust both values independently. and also you can deactivate either or with the check boxes “trace reflections” or “trace specularity”.

The glossiness subdivision controls the exactness of the calculation, higher values produce a more exact solution but render longer. most time when using proper AA settings 8 might be enough. for high level surfaces you might want to set a higher value like 16 or 32 etc. last not least there are also Fresnel settings below:

You can turn Fresnel behavior on or off, when on the layer transparency get disabled, because this is now controlled by the Fresnel, the IOR gives again real world behavior. in reality almost all materials have a certain amount of glossy reflectivity and also a Fresnel behavior with a certain IOR. Glass has a IOR of 1.5- 1,75, ceramics, plastics, polished wood, etc. have an IOR of 3-6, metals have IOR starting with 10 going up to 200. You can also adjust the color of the Fresnel. it does not have to be black and white. often gray shades or even slight colors give good results, as glossy reflections are very important for all kind of high level materials we have implemented 5 specular layers to mix!

You can each setup individually and blend them together via the specular layer transparency or Fresnel behavior. each layer can have its on glossiness, own anisotropy, colors, filters...this is excellent for car paints, silk, plastics, multilayer materials like coated woods, brushed metal etc.

You can also use one layer for only specular effects and one only for glossy reflection to have different controls and colors for both. the variation is only limited by your imagination:-)

The specular layer in the Vray material gives a totally new way to build materials, as all real world materials have a specular/glossy reflection, so it is good that they render fast in vray, also in combination with GI and refraction....

Specular Type

Type - this determines the type of specular (the shape of the highlight): Phong, Blinn and Ward. They all look a bit different. Blinn and Ward (good for metals) also offer true anisotropy for specular and glossy reflections.

Specular Color

Color - this is the specular color of the material.
Brightness - use this setting to adjust the brightness of a channel`s color. The Brightness setting functions somewhat like a multiplier and can be set to greater than 100%.
Texture Map - here an image texture or shader can be defined.
Mix Mode - use these parameters to mix the color and texture panes using one of four modes. The default mode for all channels is Normal. If you load a texture or shader, it is placed on a layer above the color (i.e. the texture is placed on top of the color). Please consult the Cinema4d documentation about the different mix modes.
Mix Strength - defines the mixing proportion between the texture and color.

Specular Layer Transparency

Color - this is the transparency color of the material.
Amount - use this setting to adjust the transparency of a channel.
Texture Map - here an image texture or shader can be defined.
Mix Mode - use these parameters to mix the color and texture panes using one of four modes. The default mode for all channels is Normal. If you load a texture or shader, it is placed on a layer above the color (i.e. the texture is placed on top of the color). Please consult the Cinema4d documentation about the different mix modes.
Mix Strength - defines the mixing proportion between the texture and color.
Invert - This option simply inverts the Texture Map.

Specular Layer Parameters

Soften edges - use this setting to make "rough" edges more soften.
Highlight glossiness - this determines the shape of the highlight on the material.
Texture Map - here an image texture or shader can be defined.
Mix Strength - defines the mixing proportion between the texture and color.
Invert - This option simply inverts the Texture Map.
Reflection Glossiness - controls the sharpness of reflections. A value of 1.0 means perfect mirror-like reflection; lower values produce blurry or glossy reflections.
Texture Map - here an image texture or shader can be defined.
Mix Strength - defines the mixing proportion between the texture and color.
Invert - This option simply inverts the Texture Map.
Use Interpolation - this specifies on what occasions glossy rays will be treated as GI rays:
  • Never - glossy rays are never treated as GI rays.
  • Only for GI rays - glossy rays will be treated as GI rays only when GI is being evaluated. This can speed up rendering of scenes with glossy reflections and is the default.
  • Always - glossy rays are always treated as GI rays. A side effect is that the Secondary GI engine will be used for glossy rays. For example, if the primary engine is irradiance map, and the secondary is light cache, the glossy rays will use the light cache (which is a lot faster).
Anisotropy - determines the shape of the highlight. A value of 0.0 means isotropic highlights. Negative and positive values simulate "brushed" surfaces.
Texture Map - here an image texture or shader can be defined.
Invert - This option simply inverts the Texture Map.
Anisotropy Rotation - determines the orientation of the anisotropic effect in degrees (rotation in degrees). Different brushed surfaces can be simulated by using a texture map for the anisotropy rotation parameter.
Anisotropy axis - controls how the direction for the anisotropic effect is chosen.
Texture Map - the direction is based on the selected texture or shader.
Invert - This option simply inverts the Texture Map.
Glossiness Subdivs - controls the quality of glossy reflections. Lower values will render faster, but the result will be more noisy. Higher values take longer, but produce smoother results.
Back side - if this is true, specular will be computed for back-facing surfaces too. Note that this affects total internal specular too (when specular are computed).
Cutoff - this is a threshold below which specular will not be traced. VRAYforC4D tries to estimate the contribution of specular to the image, and if it is below this threshold, these effects are not computed. Do not set this to 0.0 as it may cause excessively long render times in some cases.
Trace Reflections - if this is off, reflections will not traced.
Trace Specular - if this is off, specular will not traced.
Trace Depth - represents the maximum number of bounces that will be computed for reflections and specular.
Refl Dim Distance - enables the Dim distance parameter which allows you to stop tracing reflection rays after a certain distance.
Dim Distance -pecifies a distance after which the reflection rays will not be traced.
Dim Falloff - a fall off radius for the dim distance..

Specular Layer Fresnel

Use Fresnel - checking this option makes the specular strength dependent on the viewing angle of the surface. Note that the Fresnel effect depends on the index of refraction as well.
Fresnel IOR - the IOR to use when calculating Fresnel specular.
Reflectance 90 Degree - reflection color.
Texture Map - the direction is based on the selected texture or shader.
Invert - This option simply inverts the Texture Map.
Reflectance 0 Degree - refraction color. Note that the actual refraction color depends on the reflection color as well.
Texture Map - the direction is based on the selected texture or shader.
Invert - This option simply inverts the Texture Map.
Map Preview Size - Here you’ll find entries from 64x64 (16 KB) to 4096x4096 (64 MB). The value controls the internal resolution of the map — the higher you set this value, the more detailed the map will be in the viewport. The value has no effect on the rendered result.Proceed with caution when increasing the Map Preview Size. Higher settings require more RAM and increase the filesize of the CINEMA 4D scene. OpenGL is also affected because the map previews must be loaded into the graphics card’s memory.

Notes

In ward note it is not possible to have no specularity, the result will be black, this lies in the nature of ward, when using ward don not deactivate trace specular or do not set the specular glossiness to 1 use 0.99 instead p.e.

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