Base Properties

Here you will find the settings for the diffuse properties of the surface.

This defines the color of the surface for diffuse direct lighting or indirect global illumination. Setting diffuse color to black results in no diffuse lighting.

Base Color: Light Blue Metalness: 0	Yellow	Grey	Black
Base Color: Light Blue Metalness: 1	Yellow	Grey	Black

This scales the overall amount of diffuse lighting, with 0.0 resulting in no diffuse and 1.0 resulting in maximum diffuse.

Base Weight: 1.0	0.5	0.0

The Diffuse Model determines how the diffuse illumination on the surface is evaluated and thus how the brightness gradients on the surface are calculated. Two models are available:

• Oren-Nayar: This can be used to simulate the diffuse illumination of smooth and also rough surfaces. A special Diffuse Roughness value is available to blend between a smooth and a rough surface.
• d'Eon Lambertian Spheres: This is a special mode designed only for rough materials. Think here, for example, of small-pored or dusty surfaces. One characteristic of this is, among other things, an increase in color saturation with very flat incident light.

Oren-Nayar	d'Eon Lambertian Spheres

This setting is only available for the Oren-Nayar Diffuse Model. This controls the roughness of the diffuse lighting and is useful for simulating matte/dirty surfaces. A roughness of 0.0 is equivalent to a perfectly smooth surface, or traditional Lambert shading.

Base Roughness: 0	1

Controls the metalness weight with a range from 0.0 and 1.0, where 0.0 is a dielectric material that uses the Reflection settings to control the reflectance and 1.0 is a fully reflective metal material. When metalness is used Base Color controls the primary color of the metal and Reflection Color controls the edge tint.

Values between 0.0 and 1.0 results in a blend between the two types of material.

An IOR to Metal Tints node can be used with a Standard Material for separate IOR control for the red, green, and blue channels.

Metalness: 0	0.5	1

Most real-world materials exhibit some amount of reflection. The two most visible aspects of reflection are its blurriness (driven by Roughness) and its strength (driven by the Weight and IOR settings).

The Redshift Standard Material uses a GGX BRDF.

Controls the color of reflections on the surface. In most cases this should be left at the default white, but it may be necessary to tint reflections a different color for metals. Reflections are disabled when the reflection color is black.

When using a Metalness workflow, Reflection Color tints the reflections seen on the edges of an object while the Base Color tint the remainder of the reflections that are seen at a facing angle.

In the examples below note the difference in reflection color behavior when metalness is used, on non-metallic surfaces all reflections take on the reflection color while on metallic surfaces only reflections along the edges are tinted. Additionally, a black reflection color completely disables reflections on a non-metallic surface while only the edge reflections are dimmed on a metallic surface.

Reflection Color: White (default) Metalness: 0 Base Color: Grey	Yellow	Pink	Black
Reflection Color: White (default) Metalness: 1 Base Color: Grey	Yellow	Pink	Black

This is a multiplier of the reflection tint. Reflections are disabled when this value is 0.0.

When using a physically based workflow this should be left at 1.0.

Reflection Weight: 1.0 (default)	0.25	0.0

Controls the roughness of the surface reflection. Higher values scatter light in more random directions resulting in blurry reflections, a value of 1.0 results in an almost diffuse appearance. Lower values concentrate the light into sharper and more distinct reflections, a value of 0 results in a perfectly 'polished' surface.

Roughness simulates microfacet surface imperfections or a porous structure by controlling how light bounces off the surface. As roughness increases reflected light scatters all over the scene, simulating a bumpy uneven surface, and therefore less of it bounces back into the render camera which results in a visually dimmer overall reflection. However, the amount of light being reflected is the same, regardless of roughness, due to energy conservation. As roughness decreases the reflected light is scattered less, simulating a very smooth surface, with more of it bouncing back directly into the render camera resulting in brighter and sharper reflections. This is why wet materials tend to look shiny, liquids — which tend not to exhibit any surface roughness — fill in the gaps of an otherwise porous surface creating the appearance of a smooth surface and therefore brighter reflections.

Reflection Roughness: 0.0	0.25	0.75	1.0

IOR is short for Index Of Refraction and determines how the light bounces when reflected off of or refracted through a material. As this is a physical based value, you can look up the IOR for a specific material online. Most dielectric materials tend to have an IOR between 1.4-1.6

IOR defines how light rays traverse a medium and bend at each point when changing mediums. A value of 1 is equivalent to how light behaves in a vacuum, resulting in no bending of the light as a vacuum does not interact with the light rays at all. In the real world, normal materials never have an IOR below 1 because that would be impossible since it would mean light travels faster in this medium than it does in a vacuum.

Reflection IOR: 1.25	1.5 (default)	3.0	1.0

This allows to you stretch reflections in a particular axis. Anisotropy is used to emulate materials such as brushed metals where surface roughness is focused in a particular direction. You have to increase Reflection Roughness above 0.0 to see the effect.

Reflection Anisotropy: 0 (default)	0.75	1.0

Rotates the direction of the anisotropic reflections. Input values range 0 to 1 which is equal to the rotation angles 0° to 360°.

These settings set the refractive transparency of the material. A full refraction calculation needs a double sided geometry. To see refractive tint one a single sided geometry, you have to activate the Thin Walled option in the Geometry section.

A transmissive object's shadow can have a very large impact on the overall look and realism of an object, for information on controlling a transmissive object's shadow please see the Advanced Transmission section.

This is the refraction tint. To be physically correct, when used in conjunction with Subsurface Scattering or Transmission Scatter, this should be white.

Transmission Color: White (default) Transmission Weight: 1	Green	Orange	Black

This is a multiplier of the refraction tint. When 0.0 refraction transparency is disabled.

Transmission Weight: 1 Transmission Color: White	0.25	0.75	0 (default)

The Extra Roughness parameter allows for transmission roughness that can be higher or lower than Reflection Roughness. This is because the Reflection Roughness parameter also affects the transmission roughness result, how blurry refractions appear.

Extra Roughness can be set from -1 to 1, the default value of 0 results in Transmission Roughness that is equal to Reflection Roughness.

The example images below demonstrate the Reflection Roughness being used to control the transmission roughness.

Reflection Roughness: 0 Extra Roughness: 0 Transmission Color: Red	0.2 (default) 0	0.5 0	0.75 0

Positive or negative values can be used for Extra Roughness to counteract Reflection Roughness so that refractions can be more or less blurry than reflections.

The example images below demonstrate offset values between the two parameters along with the calculated transmission roughness equivalent which is just the difference between Extra Roughness and Reflection Roughness.

Extra Roughness: 0 Reflection Roughness: 0 Transmission Roughness : 0 Transmission Color: Red	- 0.2 0.2 0	- 0.4 0.5 0.1	0.5 0.2 0.3

Controls the number of samples used for transmission refractions, higher transmission roughness will need more samples to get a clean "noise-free" result. Higher numbers will reduce grain issues, but will take longer to render and vice-versa.

Controls the distance in scene units a ray needs to travel before the transmission color reaches full saturation. As light travels through a medium, some wavelengths of light get absorbed/attenuated making transmissive objects darker/lighter in regions of differing thicknesses. Therefore, Transmission Depth should be set in accordance with the actual thickness of the object taken into consideration. At higher values, the visual density of the object decreases resulting in less absorption of color in the object.

For example, with a transmission color of red, when the depth is low the transmission color is hit early resulting in a rich red color that makes the object look dense — when the ray continues to travel farther than the depth value the transmission color becomes an even darker shade of red until it starts to look black and opaque. On the other hand, if transmission depth is high it will take longer for the ray to reach full saturation, resulting in a desaturated red look in the thinnest parts of an object that make it look more like clear glass. When a depth value of 0 is used the transmission is fully tinted with the Transmission Color at all depths.

In the examples below take note of the different behavior Transmission Depth has when Transmission Scatter Color is black versus grey. At a transmission depth of 0 no scattering takes place and transmission looks the same regardless of the scatter color. When the depth is low and the scatter color is black the object looks dark but clear, however when the scatter color is grey the object looks foggy due to the single-scattering taking place which is an ideal look for plastics. At higher depth values both results begin to converge as the scattering effect becomes less pronounced and the object starts to look glassy again.

Transmission Depth: 0 (default) Transmission Scatter Color: Black (default) Transmission Color: Red	0.01 to 1	1 to 20
Transmission Depth: 0 (default) Transmission Scatter Color: Grey Transmission Color: Red	0.01 to 1	1 to 20

A Transmission Depth value greater than 0 is required for transmission scattering.

Controls the subsurface single scattering component which simulates microscopic particulate suspended in a medium, this is similar to multiple scattering but better suited to thinner volumes. Transmission scattering is useful for controlling subsurface scattering in plastics, thick fluids like orange juice or milk, and large volumes of thin fluids like the ocean to reproduce its typical blue tint.

Lighter colors result in more scattering while darker colors result in less scattering, by default the black scatter color results in no scattering. For more information on controlling the scattering look see the Transmission Depth parameter above.

Scatter Color: Black (default) Transmission Depth: 1 Transmission Color: White	Grey	White	Red	Green

Controls the direction transmissive light is scattered.

The default anisotropy of 0 results in isotropic scattering, when the light scatters equally in all directions. Positive values increase the chance for forward scattering, when more light is scattered in the direction the light rays are already traveling. Negative values increase the chance for back scattering, when more light is scattered back towards the location of the light source.

In the examples below, note how the final result is highly dependent on the location of the light source relative to the transmissive object. All examples showcase a transmission anisotropy from -0.8 to +0.8, positive values frequently lead to a more glassy appearance while negative values lead to a more frosted look.

Transmission scattering, like all blurry effects, will need more samples to get a clean "noise-free" result. Higher numbers will reduce grain issues, but will take longer to render and vice-versa.

This value describes how much the refractive index (IOR) in a transparent material varies across light spectrum wavelengths resulting in a color shift in the material. Lower values result in more intense dispersion while higher values result in little to no dispersion. With a default value of 0 dispersion is disabled. Dispersion behaves similarly to a roughness effect so it can add extra noise to the scene.

Typical values start at 10 for glass and around 70 for diamond, in general higher quality materials exhibit lower amounts of dispersion.

Dispersion: 0 (default)	0.01 to 1	1 to 5

Subsurface Scattering (SSS) simulates light that penetrates the surface of an object and gets scattered around inside the geometry. Some of this light may exit the object again and illuminate the surface in that area. This effect is common for many real world materials, but best known for skin, wax candles, plastic, and even stones.

The general look of subsurface scattering is driven by three main components, the overall color (subsurface color), the color of the light that scatters inside the object and then returns to the surface (subsurface radius), and the total distance that the subsurface scattering effect can travel which makes things look more or less dense (subsurface scale). The subsurface scattering effect is very scale dependent so it's important to have an understanding of your scene's scale and the unit of measurement that you are working in.

For example, in human skin a skin tone would be appropriate for subsurface color, a generally reddish color for subsurface radius to emulate the blood vessels underneath the skin, and a relatively low scale so that the skin does not appear too thin.

The example images for the Subsurface parameters below use the Random Walk subsurface mode unless noted otherwise.

Credit to Three D Scans for the Rhinoceros model used in the example images below.

Light scattered inside the object takes on this overall color and transports it back to the surface.

In a material for human skin, a skin tone would be appropriate for the subsurface color.

Depending on the scale of the scattering this can be thought of similarly as an albedo color for subsurface scattering since low scattering values will result in a very diffuse look and where black is used no subsurface scattering will take place at all.

Subsurface Color: White (default) Subsurface Radius: Orange (0.97, 0.62, 0.11) Subsurface Weight: 1	Green	Orange	Black

This can be used to blend between diffuse surface shading and subsurface scattering. With a Weight value of 1, diffuse shading has no effect and the full Subsurface Scattering effect becomes visible.

Subsurface Weight: 0	0.5	0.75	1

Subsurface radius controls the average distance the red, green, and blue wavelengths can travel and scatter before returning to the surface.

Lighter colors (higher values) result in more scattering and darker colors (lower values) result in less scattering. The default radius color white means all colors are scattered equidistant and a black radius color results in no subsurface scattering.

For example, a radius color with RGB values (1, 0, 0) means that only the red wavelength would travel beneath the surface and the green and blue components would be completely blocked from scattering.

The radius color is a very powerful parameter to tweak for many of the most interesting subsurface scattering looks.

Subsurface radius is in scene units even though it is represented as a color input, however, it is recommended to use the subsurface scale parameter to control the overall distance subsurface light can travel.

Working this way makes it easier to author radius color maps rather than relying on high dynamic range color values above 1 in order to achieve the intended result because the total distance light can travel in a subsurface object is obtained by multiplying the subsurfaceRadius color values by the subsurfaceScale value.

For example, if red should scatter 7.5 scene units, green should scatter 5 scene units, and blue should scatter 1 scene unit then a radius color with RGB values (0.75, 0.5, 0.1) should be used in combination with a subsurface scale value of 10. The final result would be the same as using a radius color with RGB values (7.5, 5, 1) but with a subsurface scale of 1.

Subsurface Radius: White (default) Subsurface Color: Light Green Subsurface Scale: 0.75	Light Blue (0, 0.5, 0.1) Light Green	Red (1,0,0) Light Green	Red (1,0,0) White	Black (0,0,0) Light Green

Subsurface scale controls the overall distance in scene units subsurface scattering can travel.

For example, if your scene is using centimeters then a value of 10 results in subsurface scattering traveling up to 10 centimeters.

The total distance light can travel in a subsurface object is obtained by multiplying the Radius color values by the Scale value.

Subsurface Scale: 0 Subsurface Color: Light Green Subsurface Radius: Orange (0.97, 0.62, 0.11)	0.25	1 (default)	5

Only relevant for Random Walk mode. Values close to the extreme ends (-1 and 1) may result in an unwanted look as the light scattering becomes so highly concentrated in a single direction.

Anisotropy controls the direction light scatters inside a subsurface object within a -1 to 1 range. Adjusting a material's anisotropy allows for more artistic control and increased realism.

The default anisotropy of 0 results in isotropic scattering, when the light scatters equally in all directions. Positive values increase the chance for forward scattering, when more light is scattered in the direction the light rays are already traveling. Negative values increase the chance for back scattering, when more light is scattered back towards the location of the light source.

In the examples below, note how the final result is highly dependent on the location of the light source relative to the subsurface object. All examples showcase a subsurface anisotropy from -0.9 to +0.9, positive values frequently lead to a more glassy appearance while negative values lead to a more frosted look.

The subsurface calculation offers the following methods:

• Point-Based Diffusion- The fastest and cleanest but least accurate method, not good for detailed geometry and may be unstable during animation.
• Ray-Traced Diffusion- Visually similar to Point-Based Diffusion but more accurate and stable at the cost of increased render times.
• Random Walk (default) - The most accurate method, the best choice for detailed and thin geometry but can be slower than Ray-Traced Diffusion.

Subsurface Mode: Point-Based Diffusion	Ray-Traced Diffusion	Random Walk

Point-Based Diffusion

• Faster and smoother
• Less detailed / accurate
• Does not work in progressive rendering mode
• Requires a “prepass” stage
• Highest chance of flickering in difficult lighting situations.
• Not possible to isolate SSS effect on a particular object which can result in unnecessary “light bleeding” artifacts.

Ray-Traced Diffusion

• Slower and noisier than Point-Based Diffusion
• More detailed and accurate than Point-Based Diffusion
• Works in progressive render mode
• The higher the scatter radius the more samples are needed for clean results.
• Possible to isolate SSS effect between objects or have it affect all objects.

Random Walk

• Realistic results for detailed and thin geometries
• Calculates scattering in a volume without using preliminary estimates or simplifications of the geometry as in other methods.
• Can be slower than other methods.
• Works in progressive rendering mode
• Overlapping geometry can cause artifacts
• Not available in Redshift Material

Controls the amount of noise or grain in the Subsurface calculation. Higher numbers will reduce potential grain issues but will take longer to render and vice-versa.

Controls which objects are seen by the Scattering calculation.

• All Objects : All other objects participate in the SSS effect.
• Only Self : Contain the SSS effect in the same object only.

The Sheen effect can be used to simulate a soft backscatter effect commonly seen on fabrics like velvet or satin.

Cloth with Sheen	Cloth without Sheen

Controls the color tint of the sheen reflection.

Sheen Color: Blue	Purple	Yellow	Teal

Controls the intensity of the sheen reflection. When 0.0 the sheen effect is disabled.

Sheen Weight: 0.0 Sheen Color: Light Pink	0.5	1.0

This controls the roughness of the sheen reflection, higher values result in a softer look.

Sheen Roughness: 0.0	0.2	0.5	Textured 0.3 - 1

A sheen with high a roughness value needs more samples to get a clean "noise-free" result. Higher sheen samples help reduce noise but will take longer to render and vice-versa.

Thin Film can be used to simulate a thin, light-refracting layer on the surface. For example, the shimmer on an oil film or a soap bubble.

This is the refractive index of the thin layer on the surface. A thin film of water can be simulated with an IOR of 1.333. Since soap has an IOR of about 1.5, the thin film of a soap bubble could have an IOR of about 1.4 ((1.3+1.5)/2.0).

In the animated examples below note the massive effect thin film thickness has on color shift, both have an IOR range from 1 to 4 but the thickness is different.

The thickness of this layer is specified here in nanometers and influences the color shift on this layer. This effect looks particularly interesting when thickness is varied slightly, for example, remapping a noise texture into an appropriate thickness range.

In the animated examples below note the massive effect thin film IOR has on color shift, both have a thickness range from 0 to 300 but the IOR is different.

Thickness: 0 to 300 IOR: 2.0	0 to 300 3.0	Noise variation 100-500 2.0

These options define an additional reflection layer over the material, this is helpful to emulate properties such as varnish, the clear coat of car paint, or slimy and wet surfaces. The coating layer also has its own bump map input which allows you to define details such as scratches separate from the base of the material, or leave as perfectly smooth.

Controls the coat reflection color, using a different coat color compared to the primary reflection a two-tone effect can be achieved.

In the examples below a rough metallic shader with a triangular bump map pattern can be seen with a very shiny coating on top.

Coat Color: White (default)	Yellow	Red	Blue

Controls the intensity of the coating reflection. Coat is disabled at 0.0.

Coat Weight: 0	0.5	1

This is the roughness of the surface reflection. A roughness value of 0.0 means perfectly 'polished', or full glossiness. A roughness value of 1.0 means almost diffuse appearance.

The index of refraction used to calculate the strength of the coatings fresnel effect. An IOR of 1.0 disables the coat.

Note that the clearly defined coating specular highlight compared to the rough base metal reflection.

Coat IOR : 1	1.5	2	3

This allows to you stretch coat reflections in a direction based on the anisotropy rotation. Anisotropy is used to emulate materials such as brushed metals where surface roughness is focused in a particular direction. Reflection Roughness must be set above 0.0 to see the effect.

Coat Anisotropy: 0	0.5	1

Rotates the direction of the anisotropic reflections. Input values range 0 to 1 which is equal to the rotation angles 0° to 360°.

Blurry reflections (when Roughness is greater than 0.0) will need multiple samples to get a clean "grain-free" result. Higher numbers will reduce any potential grain issues, but will take longer to render and vice-versa.

Connect a bump map node to this input to that will only affect coating reflections. Coat bump mapping is separate from the base layer, this means you can apply details like scratches on the coating without affecting the base layer.

Alternatively, by plugging a bump map into the base 'Geometry' Bump input of the material and leaving the 'Coating' Bump input empty you can easily achieve a clear coat or varnish effect:

Coat Bump: Disabled Base Bump: Disabled	Enabled Disabled	Disabled Enabled	Enabled Enabled

Emission can be used for surface illumination effects, and when rendered with Global Illumination will emit light into the scene when the effect is strong enough based on the emission weight.

Controls the color of the emission. Emission simulates light in the scene by using indirect global illumination rays to cast diffuse lighting on other objects in the scene. The emission color blends with the underlying properties of the material, however when emission weight is high enough it will completely overpower the rest of the material.

Emission Color: Red Emission Weight: 10	Blue	Yellow	Grey	Black

A multiplier for the emissive color of the material, higher values result in brighter colors and stronger global illumination.

Geometry settings affect the overall shading and calculation of the surface. For example, here you will find the option to assign a bump map, control the overall opacity of the material or tint the entire material with a color or texture.

This color controls the overall opacity of the material, with colors closer to white being more opaque. An opacity of black means the material will be fully transparent.

Grey-scale values are typically used to describe opacity but other colors can be used with varying effects, the resulting refraction color is the inverse of opacity color.

Opacity Color: White Base Material: Blue	Grey	Black	Green	Textured
Opacity Color: White Base Material: Grey	Grey	Black	Green	Textured

This option is useful for thin refractive materials such as a pane of glass, where the ray-bending effect is not noticeable and modeling actual object thickness is not worth it. When this option is enabled, refraction rays will enter and immediately exit the medium without bending the rays.

Thin Transparent Materials in Detail

The Thin Walled option is available for rendering thin transparent objects that don't actually have modeled thickness, such as a pane of glass. For very thin objects, refractive rays will not travel enough of a distance inside the object before exiting to show any noticeable bending effect. Enabling this option preserves the reflection Fresnel effect while internally disabling any medium interface transition math that would allow rays to bend.

In the examples below you can see a noticeable difference when this option is enabled. When enabled by default, the refractions bend and distort realistically - however, when disabled no bending occurs and instead the background can be seen straight through to the other side.

Thin Walled: disabled	Thin Walled: enabled

Connect your overall bump map here.

This is an overall tint for the entire material.

The Overall Tint parameter allows you to tint the entire material after lighting has been calculated. This parameter is also useful if you want to apply additional lighting attenuation from effects such as ambient occlusion, to accentuate shadows around crevices.

Below shows examples of Overall Tint. See how it affects both diffuse lighting and reflections:

Overall Tint: White	Grey	Black	Pink	Green and blue texture	AO shader

When enabled the Overall Tint color affects the emission color. When using the Overall Tint for certain shading effects, like ambient occlusion, you should leave this option disabled for more realistic results.

In the examples below an AO shader or a texture is used to drive the Overall Tint of the emissive shader ball. When the option is enabled the AO shadow or voronoi texture affects the emissive color and strength of the ball material:

Overall Tint Affects Emission: Enabled	Disabled	(Reference) Overall Tint without Emission