DCC addons

Updated October 2026

Describes the Dousen addons for Blender, Maya, 3ds Max, Houdini, Substance Painter, and Substance Designer, and the controls each one adds to its application.

Each addon collects the publishable parts of your scene as instances, validates them, and sends the exported files to Unreal through the bridge. For the validation rules, see Asset validation. For the Unreal plugin, see Unreal Engine.

Open the panel and publish your first instance

1. In DousenDesktop, select your project and task. Open Settings → DCC Apps and check the path to the application’s executable.
2. Launch the application from the apps bar and save your scene under the project’s source root.
3. Open the Dousen panel. Maya and 3ds Max open it at startup, and the Substance applications show it as a dock. In Blender, press N over the 3D Viewport and select the Dousen tab. Houdini has no panel, so use the Dousen shelf.
4. In the Publish tab, check the instances you want to publish. If you change the scene, click Reset. In Blender, click Refresh Instances.
5. In Maya, 3ds Max, Substance Painter, and Substance Designer, if an instance’s type is wrong, right-click it and choose a type under Set Type. Point to the instance name to see its Unreal destination.
6. If your project uses a material catalog, assign materials as described in Materials and textures.
7. Click Validate (in Blender, Run Validation) and fix any errors. Then click Publish (in Blender, Publish Checked Instances).
8. Open the Publish history tab in DousenDesktop and wait for Imported and saved in Unreal.

How the addons load

DousenDesktop ships the addons, so you don’t install anything in each application. When you launch an application from the apps bar, Desktop loads its addon and passes the project, task, and sign-in details it needs. See Launching DCCs.

• An application you start from a desktop shortcut has no Dousen panel.
• After you update DousenDesktop, restart any running applications so they load the new addon code.
• If your studio runs its own startup scripts, see Loading studio tools for when they run.

What each addon can do

Maya, 3ds Max, Substance Painter, and Substance Designer share one Qt panel, with the same Publish and Perforce tabs in each. The Qt panel shows tab names in capital letters. Blender uses native panels, and Houdini uses shelf tools.

The built-in rules that offer a fix are the frozen-transform checks in Blender and Maya. 3ds Max, Painter, and Designer have no built-in fixes.

In Blender, Maya, and 3ds Max, use Publish to send meshes to Unreal. These addons also have a send_to_unreal() Python function for studio scripts.

Task context

When you select a task in DousenDesktop, Desktop sends its Jira key and changelist to every running DCC. The addons tag what you publish with the task and associate the files with its changelist. A DCC that you launch while a task is selected also receives it at startup, in the environment variables listed in Loading studio tools.

The header of each Qt panel shows the current task and the Perforce stream, or Classic depot for a project without streams. After you switch tasks, check the header before you publish.

Auto-tagging on export

When Blender, Maya, 3ds Max, or Houdini exports a mesh or animation, the addon measures the geometry and sends the numbers with the export. DousenDesktop turns them into these tags before it delivers the event, so Unreal receives them with the first import. Textures get no tags.

Desktop also saves the tags on the asset’s source record in DousenCore, and Unreal stores them as dousen_cv_* metadata that you can search in the Content Browser. There is no review step and no setting to change.

What becomes an instance?

Instances you create yourself take priority, and their objects aren’t published a second time by the automatic rule. In 3ds Max, a selection set that holds only part of a node tree takes just those nodes out of the automatic instance, which keeps the rest. In Maya, an export set that holds only part of a group takes the whole group out of automatic publishing, and the Publish tab shows a note such as |grp skipped: … Put the remaining children in their own export set. Do that, or the remaining children aren’t published. If nothing is collected, nothing is published, so organize your geometry into one of the structures above or create your own instance.

The Publish tab

The Qt panels share this tab. When you open it, Dousen collects the instances in your scene. Only checked instances are validated and published, and the checked state is saved in the scene. For the whole workflow, see Publishing assets. Screenshots on this page use a sample project.

In the results, failing and warning rules come first, and passing rules collapse into one row. The log below the results records each step. If two checked instances would export to the same file, Publish is unavailable until you rename or retag one of them.

In the New Asset controls of Blender, Maya, and 3ds Max, each optional convention dimension starts at (none), so the tag stays unset until you choose a value. Dimensions your conventions mark as required still need one.

Blender

Press N in the 3D Viewport to open the sidebar, and select the Dousen tab. The Validation, New Asset, Materials, and File Status (P4) sub-panels start collapsed.

Each instance is exported with the objects in its Collection, including an armature, so a skeletal mesh brings its rig but no other instances. Before the export, Dousen writes the convention tags to those objects as custom properties. An animation instance exports its own objects and rig to FBX, like a mesh instance.

Maya

Maya starts with a Dousen shelf and a docked panel. The panel has the tabs Publish, Perforce, New Asset, Materials, and Tools.

To group loose meshes, or a rig’s meshes and skeleton, into one instance, select them, click + Instance from Selection in the Publish tab, and enter a name. Maya creates an object set with a dousenInstance attribute. If the set holds only part of a top-level group, put the group’s other children in their own set.

Each instance exports as its own FBX file with the project’s export_presets.maya settings, and a skinned mesh includes its skeleton. An animation instance exports its own objects and skeleton roots to FBX, except a DousenClips clip, which exports through DousenClips. Before the export, Dousen writes convention tags as string attributes on the mesh transforms.

3ds Max

The 3ds Max addon requires 3ds Max 2025 or later (PySide6). 3ds Max opens the same docked panel as Maya at startup, with the same tabs, and a Dousen menu appears before the Help menu.

As in Maya, the panel’s Tools tab has Send to Painter and the Publish mesh.export on save checkbox.

To export an instance, 3ds Max selects its nodes, plus the skeleton root bones for a skinned mesh, and exports the selection as FBX. An animation instance exports its own nodes and skeleton roots to FBX. Dousen writes convention tags into each exported node’s user-defined properties as lines in the form dousen_<key>=<value>.

Substance Painter

Painter shows a docked panel with the tabs Publish, Perforce, Export, and Tools.

Textures need a target Unreal mesh. If Dousen exported the mesh, it reads the target from the mesh’s metadata sidecar. Otherwise, on the Export tab, enter the mesh path in Target Unreal mesh, for example /Game/Props/S_Crate.S_Crate, and click Use target mesh. Without a target, validation reports an error named Target Unreal mesh.

If you export with Painter’s own export dialog, Dousen publishes each exported file as a texture.export event. It prints a warning if a file’s format isn’t in the project’s texture.allowed_formats setting.

When another application sends a mesh to Painter, for example with Send to Painter, Painter replaces the mesh of the open project. If no project is open, it creates a project from the mesh.

Substance Designer

Designer shows a docked panel with the tabs Publish, Perforce, Export, Materials, and Tools.

When another application sends a mesh to Designer, Designer stores the file path for you to use in your baking graph. It doesn’t connect the mesh to a node.

Houdini

The Dousen shelf holds these tools. Dousen: Send to Painter appears only if Substance Painter was connected when Houdini loaded the addon.

The three export tools don’t run validation, so run Dousen: Validate before you export. They do run the Perforce pre-flight described in Perforce actions in the DCC. If you haven’t tagged the scene, validation infers the asset type from the saved file path.

When another application sends a mesh to Houdini, Dousen creates a geo node with a file SOP inside it.

Auto-publish on save

When auto-publish is on, each save publishes the checked instances that Dousen collects in the scene, the same ones the Publish tab lists. A save-triggered publish doesn’t run the validators. Dousen still checks instance names if your naming rule is set to error, and it stops if another user has a file locked.

The setting is saved in the scene, so check it when you open a different scene. Turn it on only after a manual publish gives the result you expect. After a save-triggered publish, check Publish history to see whether Unreal imported and saved the asset.

Materials and Nanite

Choose materials from the project catalog in the application’s material picker. The assignment carries texture bindings and parameter overrides to Unreal. In Designer, the Publish tab and Send to Unreal on the Export tab send it. The assignment also decides whether the Nanite or NonNanite validator category runs, as described in The Nanite / NonNanite gate. A geometry profile can still turn Nanite off. See Materials and textures and profile settings.

Where the addons save their data

Each addon saves convention tags, the material assignment, and the auto-publish setting in your source file, so they travel with it in Perforce. Designer saves them in sidecar files next to the package instead, so check those in with the package.

Open a file in a running DCC

A dcc.open event with a file_path opens that file in a running Houdini, Substance Painter, or Substance Designer session. Blender, Maya, and 3ds Max don’t handle the event. For the event format, see dcc.open.

Perforce actions in the DCC

Each addon shows the Perforce status of the current scene and lets you check it out, sync it, and revert it. Use the Perforce tab in the Qt panels, the File Status (P4) sub-panel in Blender, or the Perforce shelf tools in Houdini. Each button is available only when it applies to the file’s current state. In a project with a separate source repository, the scene and the Unreal files can use different Perforce servers.

Blender and Houdini use slightly different button names. See Blender and Houdini.

Before a publish exports, Dousen runs a Perforce pre-flight. This applies to publishes from Blender, Maya, 3ds Max, Substance Painter, and Substance Designer, to Painter’s save-triggered publish, and to the Houdini Dousen: Export HDA, Export VAT, and Export Alembic tools and Houdini auto-publish. If another user has one of the files locked, the publish stops and names the lock. Otherwise Dousen opens the scene and the files from your last export for edit in the task’s changelist, and adds newly created files after the export. Lock failures appear in Publish history. If you restart the DCC, the first publish afterward doesn’t know the previous outputs, so check those out yourself if your workspace is read-only. Painter and Designer publishes also run the naming check first. A publish doesn’t submit anything. Submit the task’s changelist afterward, as described in Perforce.

Which rules run

Dousen runs the rules from your project’s compiled conventions for each instance’s asset type and taxonomy. An instance with no type runs only the universal naming checks. The material assignment decides which Nanite category runs. For the rule reference, see Asset validation.

If the panel or publish is missing

• Launch the application through DousenDesktop and check the executable path in Settings → DCC Apps.
• If the panel header says Cannot connect to Dousen Desktop, open Desktop. The panel reconnects automatically.
• In Desktop, check the connected-app chips and the failed stage on the Publish history tab, and read the Logs tab. Publish history doesn’t list exports from the Houdini shelf tools, Painter’s own export dialog, or the export-only buttons on Designer’s Export tab. For those, use Show connection events.
• If the instance list is empty, make sure your scene has one of the structures in What becomes an instance?, then click Reset.
• Check the project’s source root, workspace, and target Unreal project.

For more help, see Troubleshooting. To extend the addons, see Loading studio tools and the Bridge API.