TABLE OF CONTENTS


Bend


Bend is used to bend fibres either towards or away from the surface, the reference frame of this surface can be altered by specifying new Normal and Up Vector values as well as the bend direction to vary the result.


InputTypeDescription
0Data FlowFibres


ParameterDescription
BendThe amount of bend.
Bend RandomRandomize the amount of bend.
Bend DirectionControl the bend direction.
Bend Start/EndThe point along the fibre where it should start/end bending.
NormalAn attribute used to define the surface normal, this along with the Up Vector is used to define the orientation of the bend.
Up VectorThe Up Vector, defaulting to Y, that can be used to control the orientation of the bend.



Clumping


Will introduce clumps into the groom either based on neighbouring fibres or a second input fibre object that acts as the clumping points.


InputTypeDescription
0Data FlowFibres
1Data FlowFibres


ParameterDescription
WeightOverall level of clumping.
Weight RandomRandomize the clumping weight.
Clump SizeDefine the rough size of the generated clumps.
Clump SelectionDetermines if fibres will always clump or if they need to be within a lengths distance of a clump origin. 
Base/Tip AttractionHow much the fibres will be attracted to the base/tip of a clump.
Attraction BiasThe attraction bias along the length of the fibre.
TwistCauses the fibres to twist themselves around the clump.
Twist RandomRandomize the twist effect.
Fly AwayThe higher the value the more fibres will fly away from the clump, adding a frizz effect.


Geometry

ParameterDescription
Length HandlingDepending on the configuration of your graph there are situations ( especially when using guide curves ) when a fibre is longer than a clump, this can cause stray looking hairs. Turn this to Conform If Longer will cause fibres that are longer than a clump to conform to the length of the clump.
Obey WeightThis will control how the output fibres will behave if Conform if Longer is true and the fibre is longer, if on the Weight parameter will be take into consideration, anything with a weight of 0 will be completely ignored thus retaining their length.



Comb


The Comb node is used to apply the shape of a Groom to Fibres or Particles. When applied to Fibres they will be deformed to follow the shape and direction of the Groom, when applied to Particles the N attribute ( by default ) will be set to an average of the direction of the Groom.


InputTypeDescription
0Data FlowFibres or Particles
1StrandsGroom/Guide Curves


ParameterDescription
Weightan overall weight of the effect.
Weight RandomRandomize the combing weight.
Spreadcan be used to fan the fibres along the combing direction.



Curl


Curl is used to create curls or ringlets from the input fibres, the reference frame of this surface can be altered by specifying a new Up Vector value.


InputTypeDescription
0Data FlowFibres


ParameterDescription
CurlThe amount of curl.
Curl RandomUsed to randomize the curl on a per fibre basis.
Phase RandomRandomize the phase of the curl.
Root/Tip CurlControl the amount of curl at the base/tip of the fibre.
LengthControls the length of the actual curl, this can also be thought of as the phase of the curl.
Length RandomRandomize the length of the curl.
U/V ScaleThe scale of the curl perpendicular to the fibre.
Maintain LengthIf on, the curl will resample the fibre to ensure the length is maintained post evaluation but may shorten the appearance of the result.



Direction


The Direction node can be used to adjust the overall direction of Fibres, the reference frame of this surface can be altered by specifying new Normal and Up Vector values to vary the result.


InputTypeDescription
0Data FlowFibres


ParameterDescription
WeightThe amount that the fibres follow the direction.
RandomRandomize the direction.
RollThe roll, or amount of rotation around the main axis ( defined by the Normal parameter ).
InclinationThe inclination, or amount of rotation around the secondary axis ( tangental to the Normal parameter ).
NormalThe attribute used to define the surface normal, this along with the Up Vector is used to define the frame of the direction.
Up VectorThe value for the up vector, by default this is the Y axis but can be a varying attribute to randomize the direction.



Guide


The Guide node uses the incoming guide curves to deform the fibres to follow the direction/shape of the curves, most of the control for Guides are stored on the curve shapes themselves in Maya - please see Guide Curves for more information.


InputTypeDescription
0Data FlowFibres
1StrandsGuide Curves


ParameterDescription
WeightAn overall weight of the effect.
Max Clump InfluencesThe number of input guides that should be considered for clumping/attraction.



Motion


Motion is used to add subtle movement to fur without the need to simulate dynamics, at the moment the only effect is Wind. Depending on how this is set it can also be used to simulate fluttering leaves when instances are applied.


InputTypeDescription
0Data FlowFibres


ParameterDescription
MotionThe amount of motion.
TimeA time value used to evaluate the motion.
Scene ScaleDefines the overall scene scale, by default this is set to CM to match Maya.


Wind

ParameterDescription
WindThe amount of wind.
DirectionDirection of the wind.
ScaleScale of the wind.
SpreadHow far off axis can the wind blow.
FalloffModulate the effect of the wind along the length of the fibre.



Scraggle


The Scraggle node is used to add scraggle, or controlled noise, to the length of a fibre. This is extremely useful to break up fur silhouettes and make the groom look more organic. When Maintain Length is on Yeti will adjust the output fibres to make sure the length remains the same once deformed, otherwise it is likely that the length of the fibres may increase slightly ( in some cases this may be the desired look ).


InputTypeDescription
0Data FlowFibres


ParameterDescription
ScraggleThe amount of scraggle.
Scraggle MultiplierUsed to modulate the overall scraggle value.
Scraggle RandomRandomize the amount of scraggle on a per fibre basis.
Root/Tip ScraggleModulate the effect along the length of the fibres.
Scraggle FrequencyControls the size of the scraggle effect ( similar to a phase ).
Scraggle ShiftShifts the scraggle effect along the fibre.
Maintain LengthBy default Yeti will try and maintain the fibres length, in some cases this could affect the silhouette of a character - toggling this off will apply the scraggle while still retaining the length from root to tip.
SpaceControl if the scraggle is applied using the length of the fibre as a reference space or the parameter of the fibre.
DistributionShould the scraggle be uniform along the surface or randomized for each fibre. 
PercentageControls how many of the fibres should have the effect applied. 



Width


The Width node is used to control the width attribute of the fibres, this is then passed to the renderer for the final output width used at rendertime. These are global scale values, so the Width Multiplier parameter should be used to reduce the width accordingly.


InputTypeDescription
0Data FlowFibres
1StrandsGroom/Guide curves with a width attribute.


ParameterDescription
Width MultiplierModulates the width of the fibres.
Width RandomRandomizes the width.
Base/Tip WidthControl the width along the length of the fibres.
Base/Tip Parameter
defines where along the fibre the base and tip start/end.
Minimum Widthin many cases you don’t want the fibres width to reach 0 ( or a very small number ) so this parameter lets you control a minimum width, if the resulting widths are below this they will be clamped accordingly.