This page provides information on the V-Ray Fur object.

 

Page Contents

 

Overview


VRayFur is an easy to use procedural fur plugin allowing users to create fur and effects such as grass. The fur is generated only during render time and is not actually present in the scene.

 

 

 



 

UI Paths:

||Select mesh|| > Items tab > Add Item > V-Ray Geometry > V-Ray Fur

 

 

 

 

Grow Fur On




 

Geometry Items – The fur strands will grow on the geometry selected here. Note that groups can also be selected.

Include Children – When enabled, includes all items that are children of the selected items or group locators.

Material Tag – Restricts fur growth only to polygons that have this tag. The list shows only the tags present in the surfaces connected to the selected V-Ray Fur items.

Part Tag – Restricts fur growth only to polygons that have this tag. The list shows only the tags present in the surfaces connected to the selected V-Ray Fur items.

Selection Tag – Restricts fur growth only to polygons that have this tag. The list shows only the tags present in the surfaces connected to the selected V-Ray Fur items.

 

Due to API limitations, if applying the V-Ray Fur to meshes with Modo subdivision, the selected material/part/selection tags MUST be used somewhere in the Shader Tree, even in a hidden/empty group.

 

Basic Parameters



 

 

Length – The length of the fur strands.

Thickness – The thickness of the strands.

Gravity – Controls the force that pulls fur strands 

Gravity vector X, Y, and Z – Controls the direction of the force that pulls fur strands along the X, Y, and Z-directions.

Bend – Controls the elasticity of the fur strands. When it is 0.0, the strands are stiff and are straight lines. Greater values cause the strands to bend (e.g. under the influence of gravity).

Taper – Adds a taper to the individual strands of fur. Increasing this value makes each strand thinner at its upper end, while wider at its base.

Fur Scale Globally increases the scale of the scene of the fur.


 

Using Textures to Vary the V-Ray Fur Parameters

 



Some of the V-Ray Fur parameters can be modified using textures. To do this, add the V-Ray Fur item to the Schematic viewport and connect the textures there.

Bend direction texture – This is an RGB texture which specifies the bend direction of the fur strands in texture space (according to the first UV map on the mesh). 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.

Initial direction texture – This is an RGB texture which specifies the initial direction of the fur strands, in texture space (according to the first UV map on the mesh). 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.

Length/Thickness/Gravity/Bend textures – These textures are multipliers for the corresponding parameters.

Density texture – This texture is a multiplier for the strand density. No fur will be generated where the texture values are 0. The full density as specified by the Distribution parameters will be used where the texture values are 1. The density will be cut in half where the texture value is 0.5 and so on.

Curl texture – This texture is a multiplier for the strand Curl. Black portions of the map correspond to no curl, and white represents the set curl, as specified by the Curl parameters.

 

Variation


 

 

 


Direction variation – Adds slight variation to the direction in which fur strands grow from the source object. Any positive value is valid. This parameter should be adjusted according to the scale of the scene.

Length/Thickness/Gravity/Curl var – Adds variation to the corresponding parameter values. Values range from 0.0 (no variation) to 1.0.

 

Curl


 



Curl – When enabled, adds curls to the fur.

Curl Radius – The radius of the individual curl.

Number of curls – The number of curls on a particular strand.


Geometric Detail


 

 

 

 

Knots – Controls the number of connected straight segments in which the fur strands are rendered.

Level of detail – When enabled, V-Ray generates less fur geometry for parts of the scene that 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.

LOD start distance – The distance from the camera at which V-Ray starts implementing the level of detail adjustment. Up to this distance, the fur will be generated as specified by the user, but after this value, V-Ray decreases the density and increases the thickness of the strand by a factor of two for every n units of space specified by the Rate parameter.

LOD Rate – The rate at which the detail adjustment is applied. Starting from the distance specified in the Start distance parameter, V-Ray decreases the density and increases the thickness of the strands by a factor of two for every n units of space specified by the Rate parameter.


Distribution


 


 

Distribution – Determines the density of strands over the source object:

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. 

Per face – Specifies the number of fur strands per face of the source object. Every face will generate the specified number of fur strands.

Hairs per unit area – Enables the size of the faces taken at a specified frame as specified by the Fix at Time parameter. This parameter is used in the case of deforming meshes.


Misc



 



Ignore Base Mesh Displacement – When enabled, V-Ray ignores the displacement and generates the fur based on the original undisplaced object. By default, VRayFur follows the displaced object's geometry.

 

Notes


  • For subdivision surfaces, applying V-Ray Fur on a specific material/part/selection tag REQUIRES the tag to be present somewhere in the Shader Tree
  • Multiple materials on one V-Ray Fur item is not supported in RT GPU
  • Assigning item shaders on the V-Ray Fur item is currently not supported
  • V-Ray Fur does not have a preview in Modo's 3D viewports. Instead, use V-Ray RT to set it up
  • To get a better idea of how to set up V-Ray Fur, follow this tutorial on Making grass with V-Ray Fur and Hair.