Houdini 22.0 Character KineFX

Configuring controls

Configure the look and behavior of character controls.

On this page

You can configure the look and behavior of character controls using the APEX Configure Controls SOP.

Change the look of control shapes

In this example, we build a rig for the Electra test geometry and change the look of Electra’s controls using an APEX Configure Controls SOP (see rigging a character for another example of adjusting a character’s controls):

Network for configuring a character’s controls

  1. On the Electra SOP, set Output to Skin Surface. This outputs Electra’s shape as its 1st output and Electra’s skeleton as its 2nd output.

  2. The APEX Pack Character SOP adds Electra’s shape and skeleton to a character folder structure. Turn on Add FK and Bone Deform Components to create a rig for Electra that has FK and bone deform functionality. See pack characters for more information.

  3. We use the Autorig Builder to build a rig for Electra that includes components for the root, spine, arms, and legs:

    Electra’s rig built using the Autorig Builder

  4. Enter the animate state on the APEX Configure Controls SOP - select the APEX Configure Controls SOP, turn on its display flag, and click Animate on the left toolbar.

  5. On the APEX Configure Controls SOP, add a configuration for the root controls:

    • In the General tab, click beside Control Configs.

    • Expand the Control Config multiparm entry.

    • Set the Control Group parameter to the root controls - select the root controls in the viewport and click beside Control Group. The Control Group parameter will be automatically populated with the selected controls. You can also choose from the drop-down menu or use the APEX path pattern syntax to specify groups of controls.

  6. To change the size and shape of the root controls:

    • To choose a different shape for the controls, turn on Use Shape Override and set Shape Override to the desired shape. In our example, we set Shape Override to plane_wires.

    • To change the size of the controls, turn on Use Shape Offset and change the Scale parameter.

    • To change the color of the controls, turn on Use Color and click the color chip to pick a color.

    Updated root control

Use an image as a control

In this example, we use the same setup as the previous example and replace Electra’s left hand control with an image control:

  1. Enter the animate state on the APEX Configure Controls SOP - select the APEX Configure Controls SOP, turn on its display flag, and click Animate on the left toolbar.

  2. On the APEX Configure Controls SOP, go the General tab.

  3. Click beside Control Configs to add a configuration for the left hand control.

  4. Expand the Control Config multiparm entry. Set the Control Group parameter to the hand control - select the left hand control in the viewport and click beside Control Group.

  5. Turn on Use Image.

  6. Set Path to the image. In our example, we set Path to \$HFS/packages/apex/pics/circle_ring1.png.

    Note

    It is recommended to use relative paths for the image paths, otherwise a machine-dependent absolute path may get baked into the control. For example, to ensure that the relative path is stored, use \$HFS/.../<image>.png instead of $HFS/.../<image>.png.

  7. Set the image’s pixel size and position:

    • Turn on Use Pixel Size Min/Max.

    • Set the Pixel Size Min/Max values.

    • Set the Pixel Offset to change the position of the image.

    Image control

Create a main picker control

A main picker control provides a compact, artist-friendly interface for displaying groups of controls and their configuration options without having to search for individual controls in the viewport:

Main picker control for Electra

In this example, we create a main picker control for Electra using the same setup as the previous example.

  1. Enter the animate state on the APEX Configure Controls SOP - select the APEX Configure Controls SOP, turn on its display flag, and click Animate on the left toolbar.

  2. On the APEX Configure Controls SOP, go to the Config Manager tab and turn on Enable. This creates a main picker control at the origin. By default, this control is drawn as a image.

    Note

    If the character already has an existing control at the origin, it may be difficult to see the main picker control. Zoom in to see the added main picker control.

  3. To change the image for the main picker control, set the Image parameter.

  4. Change the position of the main picker control using the Position parameter.

  5. In the Level of Detail section, the image controls (LOD1 Image, LOD2 Image, LOD3 Image) are populated by default. These image controls toggle the visibility of Electra’s controls by level of detail. The level of detail is a tag on each character control that ranks the control by importance.

    Level of detail controls

  6. Add an image control within the main picker control for the spine, arms, and legs. We start with the spine:

    • Click beside Config Controls to add a configuration.

    • From the drop-down menu beside the Config Control parameter, select the configuration control for the spine. In the viewport, the spine’s control will disappear. (It will be replaced with an image button within the main picker control once you set the Img Path parameter below.)

    • Set Img Path to a .png image you want to use as the image button for the spine. In our example, we set Img Path to \$HFS/packages/apex/pics/female_body_head.png.

    • (Optional) Set Title Img Path to a .png image with a title or label. This is displayed above the spine’s configuration options. In our example, we set Title Img Path to \$HFS/packages/apex/pics/spine_font.png.

    • Click the color chip to set the color for the spine’s configuration options. In our example, we set the color to yellow.

    Spine image controls

  7. For the left arm:

    • Click beside Config Controls to add a configuration.

    • From the drop-down menu beside Config Control, select L_claviclearm_config.

    • Set Img Path to \$HFS/packages/apex/pics/female_arm_l.png.

    • Set Title Img Path to \$HFS/packages/apex/pics/arm_font.png.

    • Set the color chip to blue.

  8. Repeat the above steps for the right arm, left leg, and right leg:

    • Replace the image paths with the appropriate left, right, arm, and leg counterparts.

    • Set the left side components to blue and the right side components to red.

    Main picker control

Create selection sets

You can use the APEX Configure Controls SOP to organize the character’s controls into selection sets. In this example, we add a selection set for the lower body controls:

  1. Enter the animate state on the APEX Configure Controls SOP - select the APEX Configure Controls SOP, turn on its display flag, and click Animate on the left toolbar.

  2. On the APEX Configure Controls SOP, turn on Preview Selection Sets.

  3. In the General tab, click beside Control Configs to add a configuration for the lower body controls.

  4. Expand the Control Config multiparm entry.

  5. Set the Control Group parameter to the lower body controls - select the lower body controls in the viewport and click beside Control Group. The Control Group parameter will be automatically populated with the selected controls.

  6. Turn on Use Selection Sets.

  7. Set the name of the selection set to add the controls to - in our example, we set Set Path to lower_body.

To...Do this

Add controls to a selection set

  1. Enter the animate state on the APEX Configure Controls SOP.

  2. On the APEX Configure Controls SOP, turn on Preview Selection Sets.

  3. In the General tab, click beside Control Configs.

  4. Expand the Control Config multiparm entry.

  5. In the viewport, select the controls to add to the selection set.

  6. Click beside the Control Group parameter.

  7. Turn on Use Selection Sets.

  8. Set Set Path to the selection set to add the controls to.

  9. Select Add from the drop-down menu beside Set Path.

Add controls to a nested selection set

Set Set Path to a nested folder, for example, /lower_body/feet. If the nested folder doesn’t exist, the APEX Configure Controls SOP will create it.

Remove controls from a selection set

  1. On the APEX Configure Controls SOP, set Control Group to the controls to remove from the selection set.

  2. In the Use Selection Sets section, set Set Path to the selection set to remove the controls from.

  3. Select Remove from the drop-down menu beside Set Path.

Replace the controls in a selection set

  1. On the APEX Configure Controls SOP, set Control Group to the controls that will replace the existing controls in the selection set.

  2. In the Use Selection Sets section, set Set Path to the selection set.

  3. Select Replace from the drop-down menu beside Set Path.

Set the color of the selection set

In the Use Selection Sets section, pick a color using the color chip.

Set the controls in the selection set to be visible

Turn on Is Visible.

KineFX

Overview

Preparing character elements

Rigging with APEX graphs

  • APEX graph basics

    Introduction to the APEX graph evaluation framework.

  • APEX graph debugger

    Inspect the values of an APEX graph’s ports within the APEX network view.

  • APEX Script basics for graph building

    An overview of APEX Script, a code interface for building APEX graphs.

  • Graphs for numerical operations

    Example graphs of numerical operations like adding two values, fetching multiple results, and retrieving information from geometry.

  • Graphs for viewport animation

    Example graphs of animate state functionality like creating controls and constraints, and defining joint hierarchies.

  • Graphs for deforming geometry

    Example of a SOP network and APEX graph for deforming a 3-joint tube geometry.

  • Graph metadata

    Information added to graph nodes and ports.

  • APEX path pattern

    A set of rules that allow you to filter and select elements within graphs, skeletons, geometry, and the character folder structure.

  • APEX graph nodes

    APEX nodes provide operations for building up the functionality of APEX graphs, which are used in KineFX to create character rigs and perform other geometry manipulation.

  • APEX updates for H22

    New and updated APEX graph nodes for Houdini 22.

Building rig graphs with APEX Script

Rigging with rig components

Animating in the viewport

  • Animation workflow

    Example networks of adding characters, props, characters, and animation to a scene.

  • Animating in LOPs

    Rig and animate characters and props in the context of a USD stage.

  • Working in the animate state

    Select and manipulate controls, define transform limits for controls, and add skin controls to a character.

  • Animate state menus and HUDs

    Menus, HUDs, toolbars, and options in the animate state.

  • Animate state hotkeys

    Hotkeys available in the animate state.

  • Posing

    Pose characters in the animation scene by using locators, copying and pasting controls, and mirroring poses.

  • Motion paths

    Visualize the motion of controls as curves in 3D space.

  • Constraints

    Create relationships between controls in the animate state.

  • Dynamic motion

    Add physically-accurate projectile motion to your animation in the animate state.

  • Ragdoll

    Add a ragdoll simulation to your animation in the animate state.

  • Full body IK

    Apply full body inverse kinematics to pose the character using high-level targets rather than manipulating individual joints.

  • Secondary motion

    Add physically-accurate effects like lag/overshoot, jiggle, and spring to your animation in the animate state.

  • Control selection sets

    A tree view of controls, selections, and selection sets for the animate state. Allows management of control selection and visibility.

  • Motion mixer

    Combine and edit the animation clips of multiple characters in a timeline-based view.

  • Character picker

    Create a 2D layout with simple buttons for selecting character controls in an animation scene.

  • Animation catalog

    Save, manage, and apply animations and single-frame poses to an animation scene.

  • Animation layers

    Create multiple layers of animation without affecting the original animation.

  • Animation toolbar

    A customizable toolbar consisting of simple slider tools that quickly apply modifications to animation controls and curves.

  • Animation bookmarks

    Frame markers that help organize and identify the different parts of your animation.

Customizing the animate state

SOP-based animation

  • Physics-based motion

    Add physically-accurate motion to your animation using the Projectile Motion and Pendulum Motion SOPs.

  • Ragdoll simulations

    Add a ragdoll simulation to your animation using the Ragdoll Solver SOP.

Deformation

  • Blend shapes

    Create blend shapes using blend shape SOP nodes.

Animation retargeting

Pre-H20

Panes

  • Motion mixer

    A timeline-based view of the animation clips and motion effects of multiple characters.

  • Character picker

    Create a 2D layout with simple buttons to select character controls in an animation scene.

  • Rig tree view

    A hierarchical view of character components, including packed character folders, KineFX rigs, and Object node rigs.

  • Animation editor

    View and edit animated parameters and their transitions between keyframes.

  • Geometry spreadsheet

    Displays details about the geometry selected in the network editor.

Appendix