Houdini 21.0 Nodes Geometry nodes

APEX Autorig Builder geometry node

Interactively applies and configures rig components in the viewport.

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Since 21.0

This node allows you to interactively apply and configure pre-built and custom rig components for a character through the viewport. See rigging with the Autorig Builder for more information.

Parameters

Rig

Rig Source

The operation to perform if the character’s rig is added or modified.

Add or Update

Adds/updates the specified rig in the CharacterStream input. If no rig exists, one is created if possible.

Add or Replace

Adds/replaces the specified rig in the CharacterStream input.

Skeleton

Guide Source

The operation to perform if the character’s skeleton is added or modified. This skeleton usually represents the skeleton used for binding joints when performing bone capture. This node can either extend a capture skeleton with the new joints necessary for bone capture, or build a capture skeleton from scratch.

Add or Update

Adds/updates the specified skeleton in the CharacterStream input. If no skeleton exists, one is created if possible.

Add or Replace

Adds/replaces the specified skeleton in the CharacterStream input.

Save Guides Skeleton

When turned on, creates or updates the guide skeleton, Guides.skel, and saves it in the character folder structure in the CharacterStream output. The guide skeleton represents the hierarchy and transforms of all the joints and controls on the rig. This information is used by rig components downstream (in the APEX Autorig Builder and APEX Autorig Component SOPs) to modify and build up the rig.

Allow New Bind Joints

When turned off, doesn’t add new joints to Base.skel, which makes the skeleton processing more efficient when working with an existing skeleton that has a heavy joint count.

Shape

Shape Source

The operation to perform if the character’s shape is added or modified. The shape is used to preview the basic character shape, which helps with joint placement.

Add or Update

Adds/updates the specified shape in the CharacterStream input. If no skeleton exists, one is created if possible.

Add or Replace

Adds/replaces the specified shape in the CharacterStream input.

Open Component Catalog

Reloads/updates your library of rig components and opens the component catalog HUD.

Auto Update

When turned on, automatically updates the test rig when changes are made to the guide in the Autorig Builder viewer state.

Update Rig

Updates the test rig in the Autorig Builder viewer state.

Viewport Options

Opens the settings HUD to the Autorig Settings tab in the Autorig Builder viewer state.

Reset Guides

Resets the guide rig in the Autorig Builder viewer state. The configurations of the controls are reset to their defaults and any adjustments made to the guide positions are reset.

Reset Test Rig

Resets the test rig in the Autorig Builder viewer state. All the controls of the test animation are reset to their rest positions, and any test animation on the test rig is removed.

Settings

Orientation

Reorient

When turned on, all the joints on the input skeleton are automatically reoriented using the Main Axis and Secondary Axis.

Main Axis

The primary axis of the input skeleton that points to the next child joint. Any rig components added with this node uses this axis as their primary axis for new joints or controls, if applicable.

Secondary Axis

The secondary axis of the input skeleton, which is the rotation axis that the animator most often uses. Any rig components added with this node uses this axis as their seconday axis for new joints or controls, if applicable.

Mirror

Note

Currently, only mirroring from left to right is supported.

Left

The pattern to identify the joints on the left side of the input skeleton. This pattern is also used to name the new controls and joints on the left side of the character.

Right

The pattern to identify the joints on the right side of the input skeleton. This pattern is also used to name the new controls and joints on the right side of the character.

Skeleton to FK

Skeleton to FK

When turned on, creates an FK control for every joint on the input skeleton. This option is helpful if you want to start building a new rig with this node. Turn this off if you already have an existing rig that you only want to update with this node.

FK Exclude

The joints to exclude when building the FK controls. This parameter accepts tags.

Note

If Allow New Bind Joints is turned off, the excluded joints are not used in the calculations for building the rig. This can improve the performance of this node.

Mirror FK

When turned on, mirrors the guide joint transformations from left to right.

Mirror Exclude

The guide joints to exclude when mirroring transformations from left to right. This parameter accepts tags.

Note

Even if some guide joints are excluded when mirroring transformations, we can still mirror the functionality of the rig components on a per-component basis.

Skin Weights

Add Preview Skin Weight

When turned on, creates proxy weights for the character and provides a better preview of the rig functionality even if you don’t have capture weights on your input character.

Build

Segments

The components used to build the rig. This multiparm is populated as you add components to your rig in the Autorig Builder viewer state. Each instance of a component is defined as a segment.

You can turn a segment on or off to specify whether to add the segment to the rig. If you want to apply the segment to a specific side of the character, the Left or Right pattern should be part of the segment name.

You can set the color that is associated with the segment. This is used to color the guide joints and menu as well as the resulting controls if no color scheme is used. This helps to quickly associate the multiparm entry with the viewport representation of the segment.

The drop-down menu beside the color chip specifies the component type for the segment. The components that are available for this node are the same components that are available in the APEX Autorig Component SOP.

Note

Custom-built components can be saved and configured in the APEX Autorig Component SOP. These components will then show up in this drop-down menu as well as the component catalog in the viewport, and can be used by dragging and dropping from the component catalog. If a new component doesn’t show up in the drop-down menu, press the Open Component Catalog button to reload/update your library of components.

The button activates viewport mapping mode, which allows you to associate the segment with guide joints or guide tags. In the viewport, drag the segment to another joint on the guide and press Enter, or press ⎋ Esc to exit the mapping mode.

Advanced

The parameters in this section are set by the viewport drag and drop interactions and the menu on the guide. It is recommended to use the interactive tool instead of manually setting the values in this section.

Parent

The guide joint that the segment is parented to. New segments joints are parented to this joint.

Note

The parent guide joint is indicated with a green joint when using the mapping mode. The mapping mode can be activated by clicking the menu on the guide and selecting the segments icon, or by clicking the button beside the segment name. See “Reparent a component” in the Autorig Builder how-to for more information.

Guide Removal Pattern

The guide joints to exclude from the segment. For example, if you want to add a hand component but you only need three fingers, the extra two fingers can be marked to be excluded. See the Autorig Builder page for an example of how to do this.

Number of Elements

The number of guide joints for the segment. This is used for components that can have a varying number of guide joints, for example, a spline or FK joint chain. This parameter is populated when the number of elements is set using the number of elements icon in the guide’s menu.

Mapping

The joint mappings between the component’s reference skeleton and the working skeleton. The component’s reference skeleton is stored internally and is used to represent the joints needed by the component. It is also used to transfer tags and properties to the working skeleton.

From

The joint from the component’s reference skeleton to map from.

To

The joint on the working skeleton to map to.

Position

Mirror

When turned on, mirrors the segment from the left side of the character to the right. It doesn’t matter if the skeleton is asymmetrical; mirroring can still be applied as long as there are matching names that specify the left and right sides of the character.

Note

Currently, only mirroring from left to right is supported.

Mode

Specifies whether the Translate, Rotate, and Scale values are applied as pre-transforms or post-transforms.

Translate

The starting position of the segment.

Rotate

The starting rotation of the segment.

Scale

The starting scale of the segment.

Post Process

The parameters in this section allow you to make additional edits to your rig, including updating the colors of all the controls using a template.

The image below shows an example of using a template to set different levels of control colors - primary (dark blue), secondary (medium blue), and tertiary (light blue):

Different levels of control colors

Apply Manual Shape Edits

When turned on, manual tweaks of the rig control shapes are applied to the final output rig. The control shapes of the final rig can be tweaked by pressing O over the viewport. See “Tweak control shapes” in the Autorig Builder how-to for more information. Manual shape edits include updates to the control shape’s color, shape, and transformation.

Reset Shapes

Removes any manual changes to the shape, color, and transformation of control shapes made in the tweak control shapes mode (see “Tweak control shapes” in the Autorig Builder how-to).

Use Color Template

When turned on, sets the control colors based on the colors in the Primary Controls, Secondary Controls, and Tertiary Controls parameters. When turned off, uses the colors on the guide.

Primary Controls

Pattern

The controls to color with the primary control colors. Specify the control tags in this parameter.

Color Left

The color of the primary controls on the left side of the test rig.

Color Mid

The color of the primary controls in the middle of the test rig.

Color Right

The color of the primary controls on the right side of the test rig.

Secondary Controls

Pattern

The controls to color with the secondary control colors. Specify the control tags in this parameter.

Color Left

The color of the secondary controls on the left side of the test rig.

Color Mid

The color of the secondary controls in the middle of the test rig.

Color Right

The color of the secondary controls on the right side of the test rig.

Tertiary Controls

Pattern

The controls to color with the tertiary control colors. Specify the control tags in this parameter.

Color Left

The color of the tertiary controls on the left side of the test rig.

Color Mid

The color of the tertiary controls in the middle of the test rig.

Color Right

The color of the tertiary controls on the right side of the test rig.

Save

The parameters in this section allow you to save the combination of components added by this node (along with their configurations) as a template. A template is treated like any other rig component. It is listed in the component catalog HUD and can be applied by dragging and dropping the component onto other skeletons. See reusing rig configurations for more information.

Component Name

The name of the component. For example, if you set the namespace field to test, the name field to hello, and version to 2.0, your component will be named test::hello::2.0. The component catalog only shows the latest version.

Component Label

A user-friendly label for the component. This label is used in the Autorig Builder viewer state’s component catalog HUD and the APEX Autorig Component SOP’s Component Source drop-down menu of rig components.

Component Icon

The path to a .png file to use as an icon in the component catalog.

Component Categories

Category names that can be used as filters in the component catalog.

Deprecated

When turned on, marks the component as deprecated. After saving the component, it appears in a drop-down menu of deprecated components in the APEX Autorig Component SOP when Component Source is set to Deprecated. You can also specify a warning for the deprecated component.

Component Output File

The file path to save the component to.

Save to Disk

Saves the component to the file in Component Output File.

Inputs

CharacterStream

The APEX character geometry in a character folder structure.

Rig Template

The rig script that can be used as a template for creating a rig.

Outputs

CharacterStream

The modified APEX character geometry in a character folder structure.

Rig Template

The rig script that contains the operations for constructing the rig. This can be input into another APEX Autorig Builder SOP, acting like a template for creating another character’s rig.

See also

Geometry nodes