The Houdini Unreal Engine plugin allows Skeletal Meshes and Skeletal Mesh components to work with HDAs and NodeSync.

You can learn more about KineFX Skeletons on its documentation.

Install Houdini plugins for Skeletal Mesh

Skeletal Meshes requires two plugins loaded into Houdini to work properly. They are the KineFXtoUnreal and UnrealtoKineFX nodes.

These nodes help to either export a KineFX output node to Unreal or perform Houdini actions from an Unreal Skeletal Mesh.

To install these plugins:

  1. Locate your Houdini Engine plugins folder.

  2. Go to the HoudiniEngine\Content\NodeSync folder.

  3. Copy KineFXToUnreal and UnrealToKineFX HDA files.

  4. Paste these two files into your otls folder. In this example the location is C:\Users\PC\Documents\houdini19.5\otls.

After you install the Houdini plugins, you can follow the instructions on the NodeSync documentation to send Skeletal meshes from Unreal to Houdini and vice versa.

KineFX to Unreal setup

When working in Houdini, Skeletal meshes use a Rest Geometry and Capture Pose to make changes.

To export the Skeletal mesh back into Unreal properly, you need to use the KineFXtoUnreal node as the final output.

  1. Create a KineFXtoUnreal node.

  2. Connect your Rest Geometry output into Input1 and the Capture Pose output into Input2.

  3. Click CTRL+C to copy the KineFXtoUnreal node.

  4. Use the Fetch from Houdini procedures above to import into Unreal Engine.

Unreal to KineFX setup

When you use Send to Houdini, Houdini creates a null geometry node. To use Skeletal mesh nodes, you need both a Rest Geometry and Capture Pose to make changes.

This is when you use UnrealtoKineFX node to create these additional outputs.

The first output connects to the Rest Geometry and the second output connects to the Capture Pose.

In this example, the Skeletal mesh is now able to be edited using the Joint Deform SOP node.

Unreal

Getting started

Basics

Using Houdini Engine

Reference

Houdini Engine for Unreal Engine is a plug-in that allows integration of Houdini technology into Unreal. Session Sync and Node Sync are two features of the Houdini Engine Plugin to interact with a live session of Houdini.

This plug-in brings Houdini’s powerful and flexible procedural workflow into Unreal Engine through Houdini Digital Assets. Artists can interactively adjust asset parameters inside the editor and use Unreal assets as inputs. Houdini’s procedural engine will then “cook” the asset and the results will be available in the editor without the need for baking.

General information:

Compatibility:

Currently, the plugins has binaries that have been built for UE5.3, 5.2, 5.1, 5.0, UE4.27 and UE4.26, and is linked with the latest production build of Houdini.

Source code for the plugin is available on this repository for UE5.3, 5.2, 5.1, 5.0, UE4.27, UE4.26.

Note

UE5.1 and UE5.0 use the same source files/branches, the 5.0 sources are also intended to be used with 5.1.

Support and reporting bugs:

SessionSync

The Houdini Engine SessionSync feature allows you to connect to a session of Houdini Engine running inside Houdini with its GUI. It supports all the features of the regular Houdini Engine workflow and additional features specific to Session Sync.

Houdini Engine uses a non-UI version of Houdini while Session Sync lets you see and interact with the Houdini session through Houdini’s user interface. It also synchronizes changes made in either Unreal or Houdini so both programs can make changes and see the same results.

NodeSync

NodeSync is a feature for the Houdini Unreal Engine Plugin that enables sharing assets between Unreal and Houdini Session Sync. It works for Skeletal and static meshes.

You can send and receive data to and from Unreal without a dedicated HDA. It works with Static and Skeletal meshes as well as Actors.

Houdini Niagara

The Houdini-Niagara plugin allows you to exchange point cloud data between Houdini and Unreal’s Niagara system using the HoudiniNiagara Data Interface. You can export Houdini’s attribute data as HoudiniPointCache assets. These can then be imported into Unreal to use the Niagara systems and emitters to create complex effects and particle systems.