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Carbon Plumage

Type

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Object node (DOP only).

Description

This node defines a Carbon Plumage simulation object, its import geometry, and the plumage parameters.

A Carbon Plumage is a hybrid object, containing multiple feathers each made of several Carbon dynamic elements. Each feather can be either fully rigid or made of a rigid shaft that is welded to a soft body.

The Plumage Type can be either set to Hard Feathers or Soft Feathers. Soft feathers nicely conform to the underlying surface geometry and usually deliver more realistic results while hard feathers simulate much faster.

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An animated Carbon Plumage with Soft Feathers growing and conforming.

Both types of plumages can take up to three different feathers as input. When they are specified, Feather2 and Feather3 can only deviate in their points’ position and need to have the same topology as Feather1 (same number of points, same triangles, same vertices).

Additionally Soft Feathers must also have a shaft point attribute where the rigid part of the feather must be painted.

On the plumage groom’s points a type attribute is used to define the interpolation between the three feather geometries and a scale attribute scales independently each instance, which can result in a single Carbon Plumage containing tens of thousands of unique feathers. The plumage input geometry must be created from the groom geometry using a Carbon Plumage Mesh node.

Parameters

Activation activation

Enable this object. Use 0 to disable, any other value to enable.

Plumage

Animated Geometry geometryAnimated

Enable animated plumage geometry.

Note

It is a good practice to leave this toggled off when not using animated parameters because it impacts performance.

Plumage SOP Path plumage

Path to the SOP geometry defining the plumage, i.e. path to a Carbon Plumage Mesh.

Base Name baseName

Prefix of the name primitive attribute output used to mark the geometry of each feather.


Root Offset rootOffset

Feather root offset in surface normal direction. Must be greater or equal to the Collider Outer Fatness positioned underneath the feathers if any.


Growth Lead-In leadScales

The lead-in time in number of frames spent growing the feathers.

Note

Any value different than 0 will force the Animated flag during the growth lead-in.

Animated Scales/Types scalesAnimated

Enable animated plumage scales and types.

Note

It is a good practice to leave this toggled off when not using animated parameters because it impacts performance.


Swing Lead-In leadAngles

The lead-in time in number of frames spent swinging the feathers to their reference angles.

Animated Angles anglesAnimated

Enable animated parameters for this section by evaluating and updating the values at every frame.

Note

It is a good practice to leave this toggled off when not using animated parameters because it impacts performance.

Groom Angles

Extract all feather resting angles from the angle painted primitive attribute map.

Angle Limit angleLimit

Angular swing limit per primitive.

Note

Painted primitive attribute name: angle

Override Angles

Override all painted angles and set all feathers to conform to the same resting angle.

Angle angle

Feathers’ resting angle, set equally for all feathers.


Animated Springs springsAnimated

Enable animated plumage springs controlling the feathers’ orientation.

Note

It’s good practice to leave this toggled off when not using animated parameters because it impacts performance.

Base Parameters

Swing Stiffness swingStiffnessBase

The Swing angular stiffness.

Swing Viscosity swingViscosityBase

The Swing angular viscosity.

Twist Stiffness twistStiffnessBase

The Twist angular stiffness.

Twist Viscosity twistViscosityBase

The Twist angular viscosity.

Painted Attribute Range

Swing Stiffness swingStiffnessRange

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

Painted primitive attribute name: swingStiffness

Swing Viscosity swingViscosityRange

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

Painted primitive attribute name: swingViscosity

Twist Stiffness twistStiffnessRange

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

Painted primitive attribute name: twistStiffness

Twist Viscosity twistViscosityRange

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

Painted primitive attribute name: twistViscosity


Static Friction staticFriction

Feather static friction, between 0 and 1 but must be greater than dynamic friction.

See also

Friction

Dynamic Friction dynamicFriction

Feather dynamic friction, between 0 and 1 but must be smaller than static friction.

See also

Friction


Drag drag

Aerodynamics form drag. Shapes with a large apparent cross section exposed to the air flow and with a high form drag coefficient will receive more drag than thinner ones.

Warning

Explicit force, so high values can produce instability.

See also

Aerodynamics

Skin Drag skinDrag

Aerodynamics skin drag. Friction of the skin against the air flow. Usually much smaller, and never bigger than form drag.

Warning

Explicit force, so high values can produce instability.

See also

Aerodynamics

Lift lift

Aerodynamics lift. Lift force coefficient.

Warning

Explicit force, so high values can produce instability.

See also

Aerodynamics

Feathers

Plumage Type plumageType

The type of plumage, either Hard Feathers, Soft Feathers

Hard feathers are fully rigid, i.e. each feather is a single Carbon Rigid Body object.

While they do not always conform to the underlying surface geometry and might not look as realistic as Soft Feathers, they simulate much faster (up to 60 times faster on modern desktops).

Hard feathers have two main applications:

  • Provide fast pre-visualization results for feathers.
  • Simulate hard shells, e.g. reptile scales, porcupine spines.

Soft Feathers contains a rigid shaft, defined by the painted point attribute shaft, and a soft shell which is welded to the shaft. The soft shell is equivalent to a Carbon Cloth object using the Face-Segment-Crease Cloth Model. All of their parameters are paintable but not animated.

Feather 1

SOP Path feather1

Path to the SOP geometry defining the feather geometry.

Inner Fatness innerFatness1

Feather 1’s inner volume thickness (single sided collider when inner fatness is bigger than 0).

See also

Fatness

Outer Fatness outerFatness1

Feather 1 outer volume thickness (can be null for a single sided collider).

See also

Fatness

Mass featherMass1

Feather 1’s mass in kg.

Base Parameters

Welding Radius weldingRadiusBase1

Feather 1’s soft-welding radial limit, how far the feather is allowed to move away from its rigid attachment points.

Note

  • For use with the Soft Feathers plumage type only.
  • It is recommended to use at least a small radius for most applications. Soft-welding is a simple way to handle over-constrained situations, reducing jiggling and increasing stability.

Welding Stiffness weldingStiffnessBase1

Feather 1’s soft-welding stiffness coefficient, keeps the feather from moving away from its rigid attachment points.

Note

Welding Viscosity weldingViscosityBase1

Feather 1’s soft-welding viscous ratio, the damping of the feather moving around its rigid attachment points.

Note

Painted Attribute Range

Welding Radius weldingRadiusRange1

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

  • For use with the Soft Feathers plumage type only.
  • Painted primitive attribute name: weldingRadius

Welding Stiffness weldingStiffnessRange1

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

  • For use with the Soft Feathers plumage type only.
  • Enabled when the Welding Radius (Base or Range) is greater than zero.
  • Painted primitive attribute name: weldingStiffness

Welding Viscosity weldingViscosityRange1

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

  • For use with the Soft Feathers plumage type only.
  • Enabled when the Welding Radius (Base or Range) is greater than zero.
  • Painted primitive attribute name: weldingViscosity

Feather 2

SOP Path feather2

Path to the SOP geometry defining the feather geometry. Must have the same topology as Feather1.

Inner Fatness innerFatness2

Feather 2’s inner volume thickness (single sided collider when inner fatness is bigger than 0).

See also

Fatness

Outer Fatness outerFatness2

Feather 2’s outer volume thickness (can be null for a single sided collider).

See also

Fatness

Mass featherMass2

Feather 2 mass in kg.

Base Parameters

Welding Radius weldingRadiusBase2

Feather 2’s soft-welding radial limit, how far the feather is allowed to move away from its rigid attachment points.

Note

  • For use with the Soft Feathers plumage type only.
  • It is recommended to use at least a small radius for most applications. Soft-welding is a simple way to handle over-constrained situations, reducing jiggling and increasing stability.

Welding Stiffness weldingStiffnessBase2

Feather 2’s soft-welding stiffness coefficient, keeps the feather from moving away from its rigid attachment points.

Note

Welding Viscosity weldingViscosityBase2

Feather 2’s soft-welding viscous ratio, the damping of the feather moving around its rigid attachment points.

Note

Painted Attribute Range

Welding Radius weldingRadiusRange2

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

  • For use with the Soft Feathers plumage type only.
  • Painted primitive attribute name: weldingRadius

Welding Stiffness weldingStiffnessRange2

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

  • For use with the Soft Feathers plumage type only.
  • Enabled when the Welding Radius (Base or Range) is greater than zero.
  • Painted primitive attribute name: weldingStiffness

Welding Viscosity weldingViscosityRange2

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

  • For use with the Soft Feathers plumage type only.
  • Enabled when the Welding Radius (Base or Range) is greater than zero.
  • Painted primitive attribute name: weldingViscosity

Feather 3

SOP Path feather3

Path to the SOP geometry defining the feather geometry. Must have the same topology as Feather1.

Inner Fatness innerFatness3

Feather 3’s inner volume thickness (single sided collider when inner fatness is bigger than 0).

See also

Fatness

Outer Fatness outerFatness3

Feather 3’s outer volume thickness (can be null for a single sided collider).

See also

Fatness

Mass featherMass3

Feather 3’s mass in kg.

Base Parameters

Welding Radius weldingRadiusBase3

Feather 3’s soft-welding radial limit, how far the feather is allowed to move away from its rigid attachment points.

Note

  • For use with the Soft Feathers plumage type only.
  • It is recommended to use at least a small radius for most applications. Soft-welding is a simple way to handle over-constrained situations, reducing jiggling and increasing stability.

Welding Stiffness weldingStiffnessBase3

Feather 3’s soft-welding stiffness coefficient, keeps the feather from moving away from its rigid attachment points.

Note

Welding Viscosity weldingViscosityBase3

Feather 3’s soft-welding viscous ratio, the damping of the feather moving around its rigid attachment points.

Note

Painted Attribute Range

Welding Radius weldingRadiusRange3

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

  • For use with the Soft Feathers plumage type only.
  • Painted primitive attribute name: weldingRadius

Welding Stiffness weldingStiffnessRange3

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

  • For use with the Soft Feathers plumage type only.
  • Enabled when the Welding Radius (Base or Range) is greater than zero.
  • Painted primitive attribute name: weldingStiffness

Welding Viscosity weldingViscosityRange3

The multiplier of the painted primitive attribute values that add up to the base parameter.

Note

  • For use with the Soft Feathers plumage type only.
  • Enabled when the Welding Radius (Base or Range) is greater than zero.
  • Painted primitive attribute name: weldingViscosity

Self Collide selfCollide

Enable self-collision for each feather against itself. Toggling this off can improve performance but causes self-interpenetrations.

Note

For use with the Soft Feathers plumage type only.

Base Parameters

Surface Compression surfaceCompressionBase

Feather’s surface compression, must be strictly greater than 0 and usually smaller than 1, but must always be smaller than or equal to extension.

Note

For use with the Soft Feathers plumage type only.

Surface Extension surfaceExtensionBase

Feather’s surface extension, must be strictly greater than 0 and usually greater than or equal to 1, but must always be greater than or equal to compression.

Note

For use with the Soft Feathers plumage type only.

Surface Pressure surfacePressureBase

Feather’s pressure. Unit in mass/length/time^2.

Describes the force per area over a surface map exercised by a virtual fluid.

Note

For use with the Soft Feathers plumage type only.

Warning

Explicit force, so high values can produce instability.

See also

Surface Pressure

Painted Attribute Range

Surface Compression surfaceCompressionRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: surfaceCompression

Surface Extension surfaceExtensionRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: surfaceExtension

Surface Pressure surfacePressureRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: surfacePressure


Base Parameters

Stretch Stiffness stretchStiffnessBase

Feather’s stretch stiffness (mass/time^2), usually between 0.0 and 1000.0.

Note

For use with the Soft Feathers plumage type only.

Stretch Viscosity stretchViscosityBase

Feather’s stretch viscosity (mass/time), usually between 0.0 and 10.0.

Note

For use with the Soft Feathers plumage type only.

Stretch Compression stretchCompressionBase

Feather’s stretch compression, must be strictly greater than 0 and usually smaller than 1, but must always be smaller than or equal to extension.

Note

For use with the Soft Feathers plumage type only.

Stretch Extension stretchExtensionBase

Feather’s stretch extension, must be strictly greater than 0 and usually greater than or equal to 1, but must always be greater than or equal to compression.

Note

For use with the Soft Feathers plumage type only.

Stretch Equilibrium stretchEquilibriumBase

Feather’s resting length of stretch (ratio), usually between 0.25 and 1.75.

Use 1 for the default resting position.

Note

For use with the Soft Feathers plumage type only.

Painted Attribute Range

Stretch Stiffness stretchStiffnessRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: stretchStiffness

Stretch Viscosity stretchViscosityRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: stretchViscosity

Stretch Compression stretchCompressionRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: stretchCompression

Stretch Extension stretchExtensionRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: stretchExtension

Stretch Equilibrium stretchEquilibriumRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: stretchEquilibrium


Base Parameters

Bend Stiffness bendStiffnessBase

Feather’s angular stiffness (mass/length^2/time^2), usually between 0.0 and 1000.0.

Note

For use with the Soft Feathers plumage type only.

Bend Viscosity bendViscosityBase

Feather’s angular viscosity (mass/length^2/time), between 0.0 and 10.0.

Note

For use with the Soft Feathers plumage type only.

Bend Limit bendLimitBase

Feather’s crease angular limit (degree), between 0 and 180 degree.

Note

For use with the Soft Feathers plumage type only.

Painted Attribute Range

Bend Stiffness bendStiffnessRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: bendStiffness

Bend Viscosity bendViscosityRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: bendViscosity

Bend Limit bendLimitRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: bendLimit


Base Parameters

Viscous Damping viscousDampingBase

Feather’s viscous damping (1/time^2), damping control over the nodes’ group cohesion.

Note

For use with the Soft Feathers plumage type only.

See also

Viscous Damping

Painted Attribute Range

Viscous Damping viscousDampingRange

The multiplier of the painted point attribute values that add up to the base parameter.

Note

Painted point attribute name: viscousDamping

Parameter File

Use Parameter File fileOverride

Replace parameter values by expressions fetching the values from the loaded parameter file. Parameter values from the exclusion filter are left unchanged.

File Name fileName

Json file path to save this node’s current parameters to, and load the parameter file from.

Save save

Save this node’s current parameters to the specified file.

Load load

Load or reload the specified parameter file. As the overriding expressions always fetch values from the last loaded parameter file, and not from the file itself, use this button to refresh the loaded current parameter file with the values on disk.

Reload Every Time The Node Is Loaded reload

Automatically reload the parameter file when the scene is loaded. If the specified file cannot be found then the overriding expressions will use the values of the last loaded parameter file instead.

Exclusion Filter exclusionFilter

The exclusion filter allows to select which of the parameters are not to be replaced by the overriding expressions, therefore keeping their original values while all other parameters will evaluate with the values set from the last loaded parameter file.

Guide Geometry

Double Sided

Visualize the feather geometry with two distinctive colors per triangle, i.e. front faces and back faces drawn separately. The Inner Fatness and Outer Fatness of each individual feather depend on the three base feathers’ Inner Fatness and Outer Fatness values and the interpolation coefficients used for the plumage. In case of an Inner Fatness of 0, the feathers’ Outer Fatness is used as an offset for drawing both front and back faces, otherwise all back faces are drawn with an offset of Inner Fatness.

Front colorFrontr colorFrontg colorFrontb

Color used to draw the front facing side.

Back colorBackr colorBackg colorBackb

Color used to draw the back facing side.