Node Sync and Session Sync are included in the Houdini Engine plugin which can be installed using the Houdini Launcher or Houdini Engine For Unreal GitHub Repistory.

Follow the instructions on the Install Houdini Engine for Unreal.

From Unreal, you can launch a new instance of Houdini with SessionSync.

In Unreal’s main toolbar, click Houdini Engine then Open Houdini Sync Session.

A new Houdini application opens.

Learn more about Using SessionSync on its documentation page.

The Houdini Node Sync tab allows you to control various options when sending or fetching data to/from Houdini.

To open the Houdini Node Sync tab:

1. In Unreal’s main toolbar, select the Houdini Engine menu.

2. Select Houdini Node Sync.

The tab will be opened on the left of the viewport, next to the Place Actors tab.

It displays the current Houdini Engine Session status, and is divided in two sections: FETCH from Houdini, and SEND to Houdini.

The Fetch from Houdini tool allows you to send the output of your SOP/OBJ nodes in Houdini into Unreal as assets.

It can be accessed in the Houdini Node Sync tab:

1. In Unreal’s main toolbar, click on the Houdini Engine menu, then Houdini Node Sync.

To fetch data from a Houdini node:

1. In Houdini, select the output node you want to export.

2. Click CTRL + C to copy the node.

   

3. In the Houdini Node Path to Fetch section, paste your node to copy its path. Alternatively, you can also manually enter the Houdini path of the node.

4. In the Unreal Asset Name and Unreal Asset Import Folder sections, set your desired name and path for the fetch results in Unreal. If you create a path that doesn’t exist, a new folder is created.

5. Click Fetch. Your assets should appear in the content browser under the named folder.

   

By default, data will be fetched using the node’s outputs, if you disable the Use output nodes option on the Node Sync tabs, the display geo will be used instead. Output data is created incrementally by default, this can be disabled, allowing to overwrite previous fetch results, by enabling the Replace Existing Assets/Actors options in the Node Sync panels.

Only data created as assets in the Content Browser can be fetched by Node Sync. The following type of objects are supported:

• Static Meshes

• Curves (as Blueprints)

• Instancers (as Blueprints)

• Data Tables

• Skeletal Meshes

• Animation Sequences

• Geometry Collections

Note that importing Landscapes and Landscape Splines to the Content Browser is not supported as Unreal Engine does not provide a way to save these types of assets to the Content Browser.

Send to Houdini allows you to send assets from Unreal to Houdini.

1. In the Content Browser, select your Asset to send.

2. Right-click and select Send to Houdini.

   

3. In Houdini, your asset should appear.

You can select multiple assets at one time and send them to Houdini.

You can also use the World Outliner to select Actors and send them to Houdini.

You can control how the data is sent to Houdini by opening the Houdini Node Sync tab:

1. In Unreal’s main toolbar, click on the Houdini Engine menu, then Houdini Node Sync.

   

You can choose the node that will contain the sent data by modifying the Houdini Node Path To Send To section. You must provide a valid Houdini destination such as /obj/SentFromUnreal" or the send action will fail.

The Houdini Node Sync tab also gives you control over the Export Options used when sending the data to Houdini.

See Inputs to learn more about these options.

The following type of objects can be sent to Houdini in Node Sync:

• Static Mesh

• Static Mesh Components

• Instanced Static Mesh Component

• Skeletal Mesh

• Skeletal Mesh Components

• BSP Brushes

• Geometry Collection

• Geometry Collection Component

• Unreal Spline Components

• Landscape

• Landscape Splines

• Spline Mesh Components

• Foliage

• Data Tables

• Actors

• Blueprints

• Houdini Asset Actors

• Level Instances

• Packed Level Actors

• Animations (beta)