--- title: "V-Ray Fur" canonical: "https://documentation.chaos.com/space/VRAYHOUDINI/113280290/V-Ray%20Fur" format: markdown --- This page provides information on the V-Ray GeomHair node. Overview V-Ray Fur is a very simple procedural fur plugin. The fur is generated only during render time and is not actually present in the scene. It is recommended to use hair materials for hair-based objects used for simulating hairs. Basic Parameters Viewport Preview  – Enables preview in the viewport. Max. Preview Strands  – Specifies the maximum amount of strands visible in the viewport preview. Max. Preview Knots – Specifies the maximum amount of knots visible in the viewport preview. Length  – Specifies t he length of the fur strands. See the Length example below. Thickness  – Specifies t he thickness of the strands. See the Thickness example below. Gravity  – Specifies  the force that pulls fur strands down along the Z-direction. See the Gravity example below. Bend  – Specifies  the elasticity of the fur strands. When it is  0.0 , the strands are hard and are all straight lines. Greater values cause the strands to bend (e.g. under the influence of gravity). See the Bend example below. Taper  –  Adds a taper to the individual strands of fur. Increasing this value makes each strand thinner in its upper end and wider in its base. See the Taper example below. Scale  –  Globally   increases   the scale of the scene of the fur. Hou20_VRay6.2_Fur_Basic Example: Length Use this parameter to specify the  Length  of the strands. Length = 5.00 cm Length = 7.50 cm Length = 10.0 cm Length = 12.5 cm Length = 15.0 cm Length = 17.5 cm Length = 20.0 cm Length = 22.5 cm Length = 25.0 cm Example: Thickness Use this parameter to specify the  Thickness of the strands. Thickness = 0.05 cm Thickness = 0.10 cm Thickness = 0.15 cm Thickness = 0.20 cm Thickness = 0.25 cm Thickness = 0.30 cm Thickness = 0.35 cm Thickness = 0.40 cm Thickness = 0.45 cm   Example: Gravity Use this parameter to control the force that pulls the fur strands down along the Z-direction. Gravity = -3.0 cm Gravity = -2.5 cm Gravity = -2.0 cm Gravity = -1.5 cm Gravity = -1.0 cm Gravity = -0.5 cm Gravity = 0.0 cm Gravity = 0.5 cm Gravity = 1.0 cm Gravity = 1.5 cm Gravity = 2.0 cm Gravity = 2.5 cm Gravity = 3.0 cm Example: Bend Use this parameter to control the elasticity of the fur strands. When set to 0.0 , the strands are hard and all straight lines. Bend = 0.1 Bend = 0.2 Bend = 0.3 Bend = 0.4 Bend = 0.5 Bend = 0.6 Bend = 0.7 Bend = 0.8 Bend = 0.9 Bend = 1.0   Example: Taper When this parameter is set to  0.0 , no taper is applied to the strands and they have the same thickness from root to tip. Higher values make the root wider and the tip thinner. Taper = 0.1 Taper = 0.2 Taper = 0.3 Taper = 0.4 Taper = 0.5 Taper = 0.6 Taper = 0.7 Taper = 0.8 Taper = 0.9 Taper = 1 Curl Curl  –  When enabled, adds curls to the fur. Angle  – Specifies t he number of curls on a strand. See the Curl Angle example below. Radius  – Specifies t he radius of the individual curl. See the Curl Radius example below. Hou20_VRay6.2_Fur_Curl Example: Curl Angle Use this parameter to specify the number of curls on a strand. Angle = 2 Angle = 3 Angle = 4 Angle = 5 Angle = 6 Angle = 7 Angle = 8 Example: Curl Radius Use this parameter to specify the radius of the individual curl. Radius = 1 Radius = 1.25 Radius = 1.5 Radius = 1.75 Radius = 2 Radius = 2.25 Radius = 2.5 Radius = 2.75 Radius = 3 Radius = 3.25 Radius = 3.5 Radius = 3.75 Radius = 4 Level of Detail Tessellation  – When enabled, instructs V-Ray to subdivide and smooth the fur strands before rendering. Strands closer to the camera are tessellated into finer segments so that they render smooth, while strands away from camera are simplified to reduce memory usage and speed up rendering. Edge Length  –  Specifies the desired edge length, in pixels, of each final segment of the fur strands when  T essellation  is enabled. Smaller values produce smoother strands but take more memory and are slower to render. Larger values are faster to render and take less RAM, but may cause the fur strands to appear jagged. Level of Detail  –  When enabled, V-Ray generates less fur geometry for parts of the scene which are far away from the camera. This is done by decreasing the density of the fur strands and increasing their thickness. The level of detail function helps for two things. One, it conserves memory by decreasing the detail where it is too far to be visible, and two - it helps to reduce animation flickering of very fine fur strands when they are far from the camera. Start   Distance  – Specifies the distance from the camera at which V-Ray is going to start implementing the level of detail adjustment. Up to this distance the fur is generated as specified by the user, after that V-Ray is going to decrease the density and increase the thickness of the strand by a factor of two for every  n  units of space specified by the  Rate  parameter. Rate  – Specifies the rate at which the detail adjustment is applied. Starting from the distance specified in the  Start Distance  parameter V-Ray is going to decrease the density and increase the thickness of the strands by a factor of two for every  n  units of space specified by the  Rate  parameter. Hou20_VRay6.2_Fur_Detail Varience Direction  – Specifies a variation of the direction parameter. Length  – Specifies a variation of the length parameter. Thickness  – Specifies a variation of the thickness parameter. Gravity  – Specifies a variation of the gravity parameter. Curl Radius  – Specifies a variation of the curl radius parameter. Hou20_VRay6.2_Fur_Variance Distribution Source  –  Determines the density of strands over the source object. The available options are  Per Face  and  Per Area . See the Distribution example below. Per Face  – Specifies the number of fur strands per face of the source object. Every face generates the specified number of fur strands. Per Area  – The number of strands for a given face is based on the size of that face. Smaller faces have fewer strands, larger faces have more strands. Every face has at least one strand. Lock To Surface – When distribution is Per Area and fur is assigned to an animated surface, it locks the hair count to the generated hairs from the reference frame. Reference Frame – When distribution is Per Area , specifies the frame at which the source object is captured to calculate the face area. Per Area distribution type does not work with packed alembic primitives. Hou20_VRay6.2_Fur_Distribution Source: Per Face Source: Per Area Example: Distribution Use the  Distribution Per Face parameter to specify the number of fur strands per triangular face of the source object. Distribution Per Face = 1 Distribution Per Face = 2 Distribution Per Face = 4 Distribution Per Face = 8 Distribution Per Face = 16 Distribution Per Face = 32 Use the  Distribution Per Area parameter to specify the number of strands per squared scene unit. Distribution Per Area = 0.02 Distribution Per Area = 0.03 Distribution Per Area = 0.04 Distribution Per Area = 0.05 Distribution Per Area = 0.06 Distribution Per Area = 0.07 Distribution Per Area = 0.08 Distribution Per Area = 0.09 Distribution Per Area = 0.1 Options Knots  –  Controls the number of connect straight segments the fur strands are rendered in. Manual Gravity Direction  –  When enabled, manually specifies the gravity vector. Gravity Direction  – Specifies the x, y and z values of the gravity vector when the  Manual Gravity Direction is enabled. Hou20_VRay6.2_Fur_Options Textures Initial Direction  – Enables the use of Initial Direction texture - an  RGB map which specifies the initial direction of the fur strands, in texture space (according to the specified  Base map channel ). The red component is offset along the U texture direction, the green component is the offset along the V texture direction, and the blue component is the offset along the surface normal. Initial Direction Attr  – Specifies the geometry attributes. Initial Direction Texture  – Loads a file with the texture. Bend Direction  – Enables the use of Bend Direction texture - an  RGB map which specifies a bend direction of the fur strands, in texture space (according to the specified  Base map channel ). This is the direction in which the fur strands curve to (the amount of curvature is also controlled by the  Bend  parameter). The red component is offset along the U texture direction, the green component is the offset along the V texture direction, and the blue component is the offset along the surface normal. Bend Direction Attr  – Specifies the geometry attributes. Bend Direction Texture  – Loads a file with the texture. Bend  – Enables the use of Bend textures.  These maps are multipliers for the corresponding parameters, where black is a multiplier of  0.0 , and white is a multiplier of  1.0 . Note: the alpha output of the textures is used, so you may need to enable the Alpha Is Luminance attribute for the textures. Bend Attr  – Specifies the geometry attributes. Bend Texture  – Loads a file with the texture. Length  – Enables the use of Length textures.  T hese maps are multipliers for the corresponding parameters, where black is a multiplier of  0.0 , and white is a multiplier of  1.0 . Note: the alpha output of the textures is used, so you may need to enable the  Alpha Is Luminance  attribute for the textures. Length Attr  – Specifies the geometry attributes. Length Texture  – Loads a file with the texture. Thickness  – Enables the use of Thickness textures.  These maps are multipliers for the corresponding parameters, where black is a multiplier of  0.0 , and white is a multiplier of  1.0 . Note: the alpha output of the textures is used, so you may need to enable the  Alpha Is Luminance  attribute for the textures. Thickness Attr  – Specifies the geometry attributes. Thickness Texture  – Loads a file with the texture. Gravity  – Enables the use of Gravity textures.   T hese maps are multipliers for the corresponding parameters, where black is a multiplier of  0.0 , and white is a multiplier of  1.0 . Note: the alpha output of the textures is used, so you may need to enable the  Alpha Is Luminance  attribute for the textures. Gravity Attr  – Specifies the geometry attributes. Gravity Texture  – Loads a file with the texture. Density  – Enables the use of Density texture.  This map is a multiplier for the strand density. Black portions of the map correspond to zero density (effectively no fur will be generated in these areas), and white represents the normal strand density, as specified by the distribution parameters. Note that the alpha output of the texture is used, so you may need to enable its  Alpha Is Luminance  option. Density   Attr  – Specifies the geometry attributes. Density   Texture  – Loads a file with the texture. Curl  – Enables the use of Curl texture. Curl Attr  – Specifies the geometry attributes. Curl   Texture  – Loads a file with the texture. Hou20_VRay6.2_Fur_Textures   Example: Textures     These examples demonstrate the effect of using a texture in the VRayFur texture slots. The texture used for each example is seen facing the camera. The same texture is applied to a different slot of the VRayFur and the effect can be observed on the larger plane with VRayFur applied. Note that some of the examples use normal maps. Color maps can be used instead, both procedural and bitmaps, where RGB would equal XYZ respectively.   Color or normal maps can be used for  Bend direction  and  Initial direction , as those require a direction vector of three components.   The rest of the examples use simple black and white gradients, since the respective parameters require a single float value. Bend direction map (XYZ or RGB) Initial direction map (XYZ or RGB) Length map (mono) Thickness map (mono) Gravity map (mono) Bend map (mono) Density map (Mono) Curl map (Mono)