Material Editor Dialog (Advanced Mode), Fur Tab

Setting	Description
Fur	If enabled, fur is added to the material.
Material	Drop-down menu allows you to select a separate material for the fur strands. You can create a realistic base (dirt) material for the ground and then have a realistic grass material that is applied only to the fur strands.
Length	Sets, in master units, the length of each individual fur strand. Material with fur length per strand set to 70mm (left) and to 30mm (right) Note: This value can be randomly modified by settings described below.
Length Map (icon)	Determines the height of the fur across a surface. The height of the fur is based upon the intensity of the pixel in the image. Where a white pixel produces full height fur strands and a black pixel produces zero height fur strands. Results from using a black and white checker image length map
Spacing	Sets, in master units, the spacing between individual strands of fur. Material with fur spacing set to 5mm (left) and 15mm (right) Note: This value can be randomly modified in the Randomization drop-down settings.
Spacing Map (icon)	Controls the fur density across a surface. The darker the pixel in the image the less dense the fur will be in this area. In the example following, a white and dark grey checker pattern is used. In the image the dark grey areas have less dense fur.
Offset	Sets the offset distance the fur is created from the surface it is on. Material with fur offset set to 0mm (left) and 100mm (right)
Width	Sets the width at the root of each fur strand. This is defined as a percentage of the spacing between individual strands. For example, if the spacing is 15mm and the width is 10%, then the width of each strand is 1.5mm. If the Width is changed to 50% then the width of each strand becomes 7.5mm. Width set to 10% (left) and 50% (right)
Taper	Sets the amount that the width of each fur strand reduces over its length. A taper of 0% means the width of the root and tip of each fur strand is the same (7.5mm in the following example). Settings taper to 50% reduces the width to 3.75mm at the tip of the strand. Taper set to 0% (left) and 50% (right)
Type	Option menu that lets you select from the two types of geometry are available for individual fur strands. Strips — Each strand of fur is created as a strip. Cylinders — Each strand of fur is created as a cylinder. Note: Using cylinders for fur requires more memory for the geometry cache and also takes longer to render individual images. Fur created as Strips (left) and as Cylinders (right)
Billboard	Option menu that lets you select the position of the fur strands. When using the Billboard, the Taper option is disabled. None — Fur strands are a combination of both upright and flat. Trees — Each strand of fur is upright. Leaves — Each strand of fur is flat.
Rotation	Sets the amount that individual fur strands rotate at their root. A value of 100% will give a random rotation of up to 180 degrees. Strip rotation set to 0% (left) and to 50% (right)
Segments	Sets the maximum number of sections that make up a fur strand. A strand which has more bend requires more segments in order to display smoother curvature. Using more segments will generate more polygons at render time and consume more memory.
View Frustum Culling	If enabled, fur strands are only created on what is visible in the camera cone. In any type of reflection such as a mirror where the reflected area is not seen by the camera, the fur is not added.
Adaptive Sampling	If enabled, the density of the fur decreases as it recedes away from the camera, reducing the overall memory requirement for the fur geometry. This setting is used in conjunction with the Fur Rate setting. In the following images, the one on the left has adaptive sampling off and the image on the right has it on. In the right image, the amount of fur is reduced the further away from the camera it is. Same model with Adaptive Sampling off (left) and on (right)
Rate	Sets a threshold that Adaptive Sampling uses to reduce the number of fur strands. This is calculated as an average distance in pixels between two fibers. This setting is best used when there are large numbers of fur strands which recede into the distance, as in grassy fields. Larger values for fur rate increase the amount of reduction of the fur density with distance from the camera. Same model with fur rate set to 4 (left) and 8 (right)
Auto Fading	Auto Fading should be enabled only when animating scenes that use fur materials to prevent fur strands from popping in or out between frames.
Remove Base Surface	If on, only the fur strands are visible; the base surface does not display.
Use Hair Shader	If on, the specular shading normal is rotated toward the camera creating highlights that run parallel to the fur direction providing an overall more realistic "hair" type highlight. Use only when the geometry Type is set to Cylinders.
Clumps	This is the effect of fur strands gathering together in small groups. A higher Clumps value causes a tighter grouping of the strands. Clumps set to 10% (left) and 60% (right)
Clump Map (icon)	Controls the clumping of the fur across a surface; use in combination with the fur clumping value. The intensity of the pixel in the map scales the fur clumping value. A black pixel results in no clumping and a white pixel results in using the clumping value set in the dialog. In the following image, a black and white checker map is used to control the clumping.
Clump Range	Sets the distance that defines the average area of fur strands which gather together and is based on the Clumps (percentage) setting. Results of smaller (left) and larger (right) clump range settings
Flex	Sets the amount of bend for individual fur strands. A value of 0 produces straight fur strands and a value of 100% causes the fur strand to bend 180 degrees. Flex set to 20% (left) and 60% (right)
Flex Map (icon)	Controls the amount of fur flex across a surface. The intensity of the pixels in the map combine with the flex amount set in the dialog to control the fur flex across the surface. Using a black and white checker pattern flex map
Root Bend	Sets the amount that fur strands lay over towards the surface, in the direction of the fur growth. When this value is 0% the direction of the fur strand is based on the smoothed polygon normal at the base of the fur strand. As the value is increased to 100% the fur strands lay over towards the surface in the direction of the fur growth. Root bend set to zero (left) and 50% (right)
Randomization	The Randomization drop-down menu displays additional settings.
Growth	Sets the randomness of the growth of the fur strand along its length. Increasing the value, increases the randomness of the growth. Growth jitter set to zero (left) and 50% (right)
Growth Jitter Map (icon)	Controls the growth randomness across a surface. In the image below, which uses a black and white checker map, all the randomness has been switched off except growth jitter. Where the map pixels are black, there is no growth jitter and all the fur strands are the same length. In the areas where the map pixels are white, there is jitter applied to the value specified in the dialog.
Position	Sets the randomness of the position of the fur strands, with larger values increasing the randomness. This only has an effect when the fur spacing is large.
Direction	Used to randomize the angle of rotation for the root of the fur strand. Direction jitter set to zero (left) and to 50% (right)
Size	This value randomizes the overall scale of each fur strand. This change is most noticeable around the edge of the fur. Size jitter set to zero (left) and 50% (right)

Fur

If enabled, fur is added to the material.

Material

Drop-down menu allows you to select a separate material for the fur strands. You can create a realistic base (dirt) material for the ground and then have a realistic grass material that is applied only to the fur strands.

Length

Sets, in master units, the length of each individual fur strand.

Material with fur length per strand set to 70mm (left) and to 30mm (right)

Note: This value can be randomly modified by settings described below.

Length Map (icon)

Determines the height of the fur across a surface. The height of the fur is based upon the intensity of the pixel in the image. Where a white pixel produces full height fur strands and a black pixel produces zero height fur strands.

Results from using a black and white checker image length map

Spacing

Sets, in master units, the spacing between individual strands of fur.

Material with fur spacing set to 5mm (left) and 15mm (right)

Note: This value can be randomly modified in the Randomization drop-down settings.

Spacing Map (icon)

Controls the fur density across a surface. The darker the pixel in the image the less dense the fur will be in this area. In the example following, a white and dark grey checker pattern is used. In the image the dark grey areas have less dense fur.

Offset

Sets the offset distance the fur is created from the surface it is on.

Material with fur offset set to 0mm (left) and 100mm (right)

Width

Sets the width at the root of each fur strand. This is defined as a percentage of the spacing between individual strands.

For example, if the spacing is 15mm and the width is 10%, then the width of each strand is 1.5mm. If the Width is changed to 50% then the width of each strand becomes 7.5mm.

Width set to 10% (left) and 50% (right)

Taper

Sets the amount that the width of each fur strand reduces over its length.

A taper of 0% means the width of the root and tip of each fur strand is the same (7.5mm in the following example). Settings taper to 50% reduces the width to 3.75mm at the tip of the strand.

Taper set to 0% (left) and 50% (right)

Type

Option menu that lets you select from the two types of geometry are available for individual fur strands.

Strips — Each strand of fur is created as a strip.
Cylinders — Each strand of fur is created as a cylinder.

Note: Using cylinders for fur requires more memory for the geometry cache and also takes longer to render individual images.

Fur created as Strips (left) and as Cylinders (right)

Billboard

Option menu that lets you select the position of the fur strands. When using the Billboard, the Taper option is disabled.

None — Fur strands are a combination of both upright and flat.
Trees — Each strand of fur is upright.
Leaves — Each strand of fur is flat.

Rotation

Sets the amount that individual fur strands rotate at their root. A value of 100% will give a random rotation of up to 180 degrees.

Strip rotation set to 0% (left) and to 50% (right)

Segments

Sets the maximum number of sections that make up a fur strand. A strand which has more bend requires more segments in order to display smoother curvature. Using more segments will generate more polygons at render time and consume more memory.

View Frustum Culling

If enabled, fur strands are only created on what is visible in the camera cone. In any type of reflection such as a mirror where the reflected area is not seen by the camera, the fur is not added.

Adaptive Sampling

If enabled, the density of the fur decreases as it recedes away from the camera, reducing the overall memory requirement for the fur geometry. This setting is used in conjunction with the Fur Rate setting. In the following images, the one on the left has adaptive sampling off and the image on the right has it on. In the right image, the amount of fur is reduced the further away from the camera it is.

Same model with Adaptive Sampling off (left) and on (right)

Rate

Sets a threshold that Adaptive Sampling uses to reduce the number of fur strands. This is calculated as an average distance in pixels between two fibers. This setting is best used when there are large numbers of fur strands which recede into the distance, as in grassy fields. Larger values for fur rate increase the amount of reduction of the fur density with distance from the camera.

Same model with fur rate set to 4 (left) and 8 (right)

Auto Fading

Auto Fading should be enabled only when animating scenes that use fur materials to prevent fur strands from popping in or out between frames.

Remove Base Surface

If on, only the fur strands are visible; the base surface does not display.

Use Hair Shader

If on, the specular shading normal is rotated toward the camera creating highlights that run parallel to the fur direction providing an overall more realistic "hair" type highlight. Use only when the geometry Type is set to Cylinders.

Clumps

This is the effect of fur strands gathering together in small groups. A higher Clumps value causes a tighter grouping of the strands.

Clumps set to 10% (left) and 60% (right)

Clump Map (icon)

Controls the clumping of the fur across a surface; use in combination with the fur clumping value. The intensity of the pixel in the map scales the fur clumping value. A black pixel results in no clumping and a white pixel results in using the clumping value set in the dialog. In the following image, a black and white checker map is used to control the clumping.

Clump Range

Sets the distance that defines the average area of fur strands which gather together and is based on the Clumps (percentage) setting.

Results of smaller (left) and larger (right) clump range settings

Flex

Sets the amount of bend for individual fur strands. A value of 0 produces straight fur strands and a value of 100% causes the fur strand to bend 180 degrees.

Flex set to 20% (left) and 60% (right)

Flex Map (icon)

Controls the amount of fur flex across a surface. The intensity of the pixels in the map combine with the flex amount set in the dialog to control the fur flex across the surface.

Using a black and white checker pattern flex map

Root Bend

Sets the amount that fur strands lay over towards the surface, in the direction of the fur growth.

When this value is 0% the direction of the fur strand is based on the smoothed polygon normal at the base of the fur strand. As the value is increased to 100% the fur strands lay over towards the surface in the direction of the fur growth.

Root bend set to zero (left) and 50% (right)

Randomization

The Randomization drop-down menu displays additional settings.

Growth

Sets the randomness of the growth of the fur strand along its length. Increasing the value, increases the randomness of the growth.

Growth jitter set to zero (left) and 50% (right)

Growth Jitter Map (icon)

Controls the growth randomness across a surface. In the image below, which uses a black and white checker map, all the randomness has been switched off except growth jitter. Where the map pixels are black, there is no growth jitter and all the fur strands are the same length. In the areas where the map pixels are white, there is jitter applied to the value specified in the dialog.

Position

Sets the randomness of the position of the fur strands, with larger values increasing the randomness. This only has an effect when the fur spacing is large.

Direction

Used to randomize the angle of rotation for the root of the fur strand.

Direction jitter set to zero (left) and to 50% (right)

Size

This value randomizes the overall scale of each fur strand. This change is most noticeable around the edge of the fur.