Houdini 22.0 Character KineFX

IK/FK Blend

Performs a local blend between an IK and FK chain.

Since 20.5

This component sets up the necessary constraints and blends to do a local blend between an IK and FK chain.

IK/FK blend functionality

The IK/FK blend control consists of two parts - an abstract control that drives the blend value between IK and FK, and a position control that allows you to move the abstract control around:

IK/FK blend control

The IK/FK blend component uses an IK chain as a reference, so one must be set up upstream using the multi IK component. However, it is not necessary to have existing FK nodes in the hierarchy. The IK/FK blend finds the relevant skeleton joints used for IK, and automatically creates FK nodes at those joints if they don’t already exist.

Example network for setting up the IK/FK blend component

See rigging a character for an example use of this component.

Parameters

Name

The name to add to the IK/FK blend abstract and position controls. When using Segments, the segment name is also added to the controls.

Settings

Switch Visibility

When turned on, only the active set of IK/FK controls are displayed. For example, if the controls are currently set to FK, turning on this option displays only the FK controls. When turned off, the IK and FK controls are both displayed.

Control Position

The position of the abstract control as a relative offset. By default, the abstract control is placed in the middle of the joint chain.

Control Scale

The scale of the abstract control.

Promote T

When turned on, promotes the translate of the FK controls added by this component.

Promote R

When turned on, promotes the rotate of the FK controls added by this component.

Promote S

When turned on, promotes the scale of the FK controls added by this component.

Driven

Segments

Segments are tags that separate each IK/FK chain. For example, *Leg loops over tags L_Leg and R_Leg. Tags can be set up on skeleton joints using an Attribute Adjust Array SOP. See preparing skeletons for rigging for more information.

If Segments is empty, the IK/FK blend logic is run once.

Note

The segments parameter does not take APEX path patterns, for example, the #<tag> function. Instead, specify the tag names directly in this field.

IK Nodes

An APEX path pattern that specifies the IK nodes that are included in the IK/FK blend.

FK Prefix

The prefix to add to the FK chain. When setting up the IK/FK blend, you don’t need to have FK nodes in the hierarchy. The IK/FK blend component creates an FK chain if one doesn’t already exist.

FK Suffix

The suffix to add to the FK chain. When setting up the IK/FK blend, you don’t need to have FK nodes in the hierarchy. The IK/FK component creates an FK chain if one doesn’t already exist.

FK Nodes

An APEX path pattern that specifies the FK nodes to include in the IK/FK blend. This can be used if the FK nodes already exist in the rig hierarchy. The IK/FK component loops over the IK nodes, and uses the mapping value to make sure the IK and FK hierarchies match.

Parent

Parent

The main driver of the abstract control. When empty, the abstract controls are not parented.

Tags

Tags

The tags to add to the nodes created by this component.

See also

KineFX

Overview

Preparing character elements

Rigging with APEX graphs

  • APEX graph basics

    Introduction of 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