Table of Contents

This article explains the settings and values for the Corona Hair Material.


Overview


Hair has particular unique qualities that need a dedicated material. The Corona Hair Material is physically accurate and handles the unique highlights and transmission properties that hair requires, while still rendering quickly and giving you the ease of use in controlling the material that you expect from Corona. The hair material is mainly intended for creating human hair and animal fur, as it includes properties based on natural hair model (melanin pigment amount, anisotropic reflections, hair fiber caustics); however, it can be as well used to render carpet strands, fuzzy fabrics, nylon strings, and other types of synthetic fibers.

Corona supports the native Cinema 4D Hair for generating hair geometry.

The Corona Hair Material is intended only for special hair objects. Applying it to any other objects, such as boxes, spheres, or any other geometry object will most likely result in incorrect shading on those objects.

 

Edith, by Markus Skibinski, Senior 3D-Artist, Stoll. von Gati GmbH | artstation.com/markus_s


Color


Color

Level – This is the intensity (also considered as the visibility) of the color.

Melanin

Value – Controls the absorption inside hair fibers by setting the total amount of melanin pigment in the hair. This sets the overall color of hair. A value of 0% (no pigment) leads to white hair, while a value of 100% leads to completely black hair. The values between them give physically plausible human hair color.

Texture – Defines the texture map or shader that will be used to control the melanin value instead.

Pheomelanin

Value – Controls the relative amount of reddish pheomelanin pigment among the hair pigments and hence the hair redness. A value of 0% leads to 100% of eumelanin (brown pigment), and a value of 100% leads to 100% of pheomelanin (reddish pigment causing ginger coloration).

Texture – Defines the texture map or shader that will be used to control the pheomelanin value instead.

Randomize melanin – Controls the randomization of pigment amount between different hair strands. 0% means no randomization, while 100% means completely random amount of hair pigment for each hair strand.

Tint

Value – Controls the absorption inside hair fibers. Setting this value to black leads to total absorption within the hair and hence black hair with only reflection. This value is not used on its own, it only tints the color calculated from (pheo)melanin. For natural human hair color, it is recommended to leave the tint at white, where it does not modify the color calculated from (pheo)melanin. It can, however, be used to simulate hair dyes, textile fibers, etc.

Texture – Defines the texture map or shader that will be used to control the tint color instead.

Mix mode – Controls the blending mode of the texture map or shader over the color.

Mix strength – Controls the intensity of the texture map or shader that is being used.

Transmission tint

Value – Colors the light transmission through the hair fibers. For physically plausible results, it is recommended to keep this value as pure white.

Texture – Defines the texture map or shader that will be used to control the transmission tint color instead.

Mix mode – Controls the blending mode of the texture map or shader over the color.

Mix strength – Controls the intensity of the texture map or shader that is being used.

 

 

Colored reflection


Glossiness

Value – Controls the glossiness of hair in the direction of the hair length. A value of 0% leads to very rough/diffuse hair, while a value of 100% leads to the shiniest hair.

Texture – Defines the texture map or shader that will be used to control the glossiness value instead.

Tint

Value – Color tint of the secondary (colored) reflection on the hair fibers. For physically plausible results, it is recommended to keep this value as pure white.

Texture – Defines the texture map or shader that will be used to control the tint color instead.

Mix mode – Controls the blending mode of the texture map or shader over the color.

Mix strength – Controls the intensity of the texture map or shader that is being used.

 

 

Colorless Reflection


Glossiness

Value – Multiplier of glossiness parameter for the primary (colorless) reflection lobe. Increasing the value leads to a sharper primary (colorless) reflection lobe compared to other lobes (colored reflection, transmission).

Texture – Defines the texture map or shader that will be used to control the glossiness value instead.

Tint

Value – Color tint of the primary (colorless) reflection on the hair fibers. For physically plausible results, it is recommended to keep this value as pure white.

Texture – Defines the texture map or shader that will be used to control the tint color instead.

Mix mode – Controls the blending mode of the texture map or shader over the color.

Mix strength – Controls the intensity of the texture map or shader that is being used.

 

 

Reflection


Softness (aniso)

Value – Controls the overall softness of hair by changing the hair roughness along the hair width. A value of 0% leads to the roughest hair (high glossiness along hair width), while a value of 100% leads to the softest hair.

Texture – Defines the texture map or shader that will be used to control the softness instead.

Glint strength

Value – Controls the strength of random glints (i.e., caustics caused by internal reflection within elliptical hair fibers). This effect makes random strands stand out from the rest, creating the appearance of damaged hair. A value of 0% results in no random glints, a value of 100% leads to the most apparent random glints. Increasing the glint strength leads to an overall decrease in colored reflection.

Texture – Defines the texture map or shader that will be used to control the glint strength instead.

Highlight shift

Value – Shifts the highlights on the hair by changing the angle (in degrees) of scales on the hair fiber. A value of 0 leads to an identical position of colorless and colored reflection highlights; increasing the value separates the highlights more by moving the colored reflection highlight.

Texture – Defines the texture map or shader that will be used to control the highlight shift instead.

IOR

Value – Controls the index of refraction on the hair surface. A value of 1.55 is recommended for physically plausible results. Increasing the value leads to more reflection on the hair.

Texture – Defines the texture map or shader that will be used to control the IOR value instead.

 

 

 

Diffuse


Level – Diffuse component multiplier.

Color – Adds a diffuse component to the hair. Clean hair does not have this component in reality, so it should be used only in very special cases (dirt in hair, non-hair objects, etc.).

Texture – Defines the texture map or shader that will be used to control the diffuse color instead.

Mix mode – Controls the blending mode of the texture map or shader over the color.

Mix strength – Controls the intensity of the texture map or shader that is being used.

 

 

 

Opacity


Level – Specifies the opacity level. Both the opacity constant color and texture map are multiplied by this number. Setting 50% and using white color is equal to using 50% gray color or using a texture map with output level of 50%.

Color – Specifies the opacity of the material. It can be set as a constant color or mapped by a texture map.

Texture – Defines the texture map or shader that will be used instead of the above color.

Mix mode – Controls the blending mode of the texture map or shader over the color.

Mix strength – Controls the intensity of the texture map or shader that is being used.

 

 

Bump


Strength – The missing coefficient between the texture and constant color. 100% means only the constant color is used, and the value in-between blend the texture with the constant color.

Texture – Defines the texture map or shader that will be used for the bump channel.

 

 

Advanced


Material ID – Defines an ID for the material that can be used in the Corona Compositing tag or in the Corona Data shader.

GI simplification amount – When set to non-zero values, less precise global illumination is computed for this hair material. This leads to significantly less noise but also more unrealistic results.