>>> VRayFur >>>
Search Keywords: fur, hair, grass, rug
VRayFur is a very simple procedural fur plugin. The fur is generated only during render time and is not actually present in the scene.
To create a VRayFur object, you must first select a mesh from the Maya scene, then go to Create>V-Ray>Add VRayFur to selection. A new set of attributes will appear for the selected mesh.
Length - the length of the fur strands.
Thickness - the thickness of the strands.
Gravity - this controls the force that pulls fur strands down along the Z-direction.
Bend - this parameter controls 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).
Taper - allows you to add a taper to the individual strands of fur. Inceasing this value will make the each strand thinner in its upper end and wider in its base.
Sides - currently this parameter is disabled. The fur is always rendered as polygons facing the traced ray; normals are interpolated to create a smooth appearance.
Knots - fur strands are rendered as several connected straight segments; this parameter controls the number of segments.
Flat normals - when this option is on, the normal of the fur strands does not vary across the strand width. Although not very precise, this is similar to how other fur/hair solutions work. It may also help with fur antialiasing, making the job of the image sampler a little easier. When this option is turned off, the surface normal varies across the width of the strands, creating the illusion that the strands have cylindrical shape.
Direction variation - this parameter adds slight variation to the direction in which fur strands grow from the source object. Any positive value is valid. This parameter should also depend on the scene scale.
Length/Thickness/Gravity variation - these add variation to the corresponding parameters. Values are from 0.0 (no variation) to 1.0.
Distribution - determines the density of strands over the source object:
Per face - specifies the number of fur strands per face of the source object. Every face will generate 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. The size of the faces is taken at the frame, specified by the Reference frame parameter.
You can control some aspects of VRayFur with texture maps. These can be either bitmaps, or vertex color maps painted directly on the source object.
UV bases set - some of the texture maps represent vectors in texture space, where the x and y directions are derived from the u and v directions of a texture UV set. This parameter specifies which mapping channel is used.
Bend direction texture - this is 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.
Initial direction texture - this is 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.
Length/Thickness/Gravity/Bend texture - 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 that the alpha output of the textures is used, so you may need to enable the Alpha Is Luminance attribute for the textures.
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.