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Carbon Stitching

Type

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Relationship node (SOP and DOP).

Description

A Stitching is a collection of attachments between one or several pairs of Carbon Cloth/Carbon Tetra nodes. Each attachment is a collection of constraints called Stitches pairing points from each of the Carbon Cloth/Carbon Tetra nodes involved.

Two Carbon Cloth/Carbon Tetra objects are required to define each attachment, and an ordered Houdini point Group within each Carbon Cloth/Carbon Tetra reference pose geometry is required to assemble the pairs of Carbon Cloth /Carbon Tetra points constrained by Stitches.

Note

The Houdini point Group needs to be ordered, otherwise no ordered stitches will be established.

The correct way to create these groups is:

  1. Select each of the vertices in a specific order from the first part of the cloth/tetra geometry you want to stitch.
  2. Click on the Model toolbar, icon Group (or hit tab while the mouse is over the viewport and type group).
  3. In the group parameters, tick Create Ordered.
  4. Repeat the three operations above on the other cloth/tetra (or the other side of the cloth/tetra you are stitching to itself) while making sure the order and number of points selected is respected.

Attach this node after a merge node that the Carbon Cloth / Carbon Tetra node(s) are connected to, then use the drop down menus to select the Carbon Cloth / Carbon Tetra objects and groups from their lists.

_images/animation_carbon_stitching.gif

A Stitching.

Note

The Carbon Stitching relationship uses the same stretch Stiffness/Viscosity constraint as the Carbon Cloth Stretch model.

Inputs

Input #1: objects

All objects referenced by this relationship must also be connected to this input through a Houdini Merge node for the Carbon Stitching node to operate within the Carbon Simulation it is connected to.

Parameters

Activation activation

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


Properties

Animated propertiesAnimated

Update the following property values for this constraint at every frame.

Note

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

Stiffness stiffness

Stretch stiffness (mass/time^2), usually between 0.0 and 1000.0.

Similar to the Carbon Cloth Stretch Stiffness.

Viscosity viscosity

Stretch viscosity (mass/time), usually between 0.0 and 1000.0.

Similar to the Carbon Cloth Stretch Viscosity.

Compression compression

Stretch compression, must be strictly greater than 0 and usually smaller than 1, but must always be smaller than extension.

Similar to the Carbon Cloth Stretch Compression.

Extension extension

Must be strictly greater than 0 and usually smaller than 1, but must always be greater than compression.

Similar to the Carbon Cloth Stretch Extension.

Equilibrium equilibrium

Resting length of stretch (ratio) of reference length, usually between 0.25 and 1.75.

Use 1 for the default reference length.

Similar to the Carbon Cloth Stretch Equilibrium.


Stitching Pairs

Stitching Count count

The number of stitching pairs created from this node.

Cloth/Tetra A clothA#

The Carbon Cloth/Carbon Tetra object name to use with this constraint.

Cloth/Tetra B clothB#

The Carbon Cloth/Carbon Tetra object name to use with this constraint.

This can be the same object as in Cloth/Tetra A.


Reference

Animated referenceAnimated#

Update the following property values for this constraint at every frame.

Note

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

Point Group A groupA#

The points from Cloth/Tetra A’s geometry that are used for the stitching. Must be the same number of points as Point Group B.

Point Group B groupB#

The points from Cloth/Tetra B’s geometry that are used for the stitching. Must be the same number of points as Point Group A.

Parent Pose parentMesh#

Cloth/Tetra A’s pose in the stitching reference space.

Note

This parameter is optional.

Child Pose childMesh#

Cloth/Tetra B’s pose in the stitching reference space.

Note

This parameter is optional.


Properties Override propertiesOverride#

Allows to specify individual properties for this constraint pair, therefore ignoring the local properties set above for the node.

Properties

Animated propertiesAnimated#

Update the following property values for this constraint at every frame.

Note

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

Stiffness stiffness#

Stretch stiffness (mass/time^2), usually between 0.0 and 1000.0.

Similar to the Carbon Cloth Stretch Stiffness.

Viscosity viscosity#

Stretch viscosity (mass/time), usually between 0.0 and 1000.0.

Similar to the Carbon Cloth Stretch Viscosity.

Compression compression#

Stretch compression, must be strictly greater than 0 and usually smaller than 1, but must always be smaller than extension.

Similar to the Carbon Cloth Stretch Compression.

Extension extension#

Must be strictly greater than 0 and usually smaller than 1, but must always be greater than compression.

Similar to the Carbon Cloth Stretch Extension.

Equilibrium equilibrium#

Resting length of stretch (ratio) of reference length, usually between 0.25 and 1.75.

Use 1 for the default reference length.

Similar to the Carbon Cloth Stretch Equilibrium.

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

Show Stitches showguide

Display the stitches as colored lines between the Cloth/Tetra A and Cloth/Tetra B objects.

Stitches colorStitchesr colorStitchesg colorStitchesb

Color used to draw the stitches when Show Stitches is toggled on.