FBX Animation Pipeline

Overview

Animation support in the FBX import pipeline provides a simple workflow for getting animations for skeletal meshes from 3D applications into Unreal for use in games. Currently, only a single animation for each skeletal mesh can be exported/imported in a single file.

This page is a technical overview of using the FBX content pipeline to import animations into UnrealEd. See the FBX Best Practices page for more information, tips, and tricks on working with the FBX content pipeline in a development environment.

IMPORTANT: As of September 2011 the UE3 FBX import pipeline uses FBX 2012. Using a different version during export may result in incompatibilities.

Naming

When importing animations into UnrealEd using the FBX format, the animation sequence will be named the same as the name of the file. When importing animations along with a skeletal mesh, the AnimSet that is created will be taken from the name of the root bone in the animation sequence. This can easily be renamed after the import process is complete through the Content Browser.

Creating Animations

Animations can be unique to a single skeletal mesh or they can be reused for any number of skeletal meshes as long as each skeletal mesh uses the same skeleton. All you really need to create an animation and export it into UnrealEd using the FBX pipeline is a skeleton that has been animated. Having a mesh bound to the skeleton is completely optional, though it makes the process of creating the animation much easier as you can see how the mesh is deforming during the animation. At export time, only the skeleton is required though.

For complete details on setting up and creating animations in 3D applications for use in Unreal Engine 3, see the Creating Animations page.

Exporting Animations from 3D Apps

Animations must be exported individually; one animation per skeletal mesh to a single file. The steps below are for exporting a single animation into a file by itself. The mesh bound to this skeleton has been hidden as it is not absolutely necessary for exporting animations by themselves.

3dsMax

1. Select the bones corresponding to the animation to be exported in the viewport.
   
2. In the File menu choose Export Selected (or Export All if you want to export everything in the scene regardless of selection).
   
3. Choose the location and name for the FBX file to export the animation to and click the button.
   
4. Set the appropriate options in the FBX Export dialog. For the purposes of exporting animations, you must enable the Animations checkbox.
   
5. Click the button to create the FBX file containing the mesh(es).

Maya

1. Select the joints to be exported in the viewport.
   
2. In the File menu choose Export Selection (or Export All if you want to export everything in the scene regardless of selection).
   
3. Choose the location and name for the FBX file to export the animation to and set the appropriate options in the FBX Export dialog. For the purposes of exporting animations, you must enable the Animations checkbox.
   
4. Click the button to create the FBX file containing the mesh(es).

Importing Animations

The FBX animation import pipeline allows for importing both a skeletal mesh and animation all at once, or importing one or the other individually.

Skeletal Mesh with Animation

1. Click the button in the Content Browser. Navigate to and select the FBX file you want to import in the file browser that opens. Note: you may want to select in the dropdown to filter out unwanted files.
   
2. Choose the appropriate settings in the Import dialog. Make sure that Import Animations is enabled. Note: The name of the imported mesh will follow the default Naming Rules. See the FBX Import Dialog section for complete details of all of the settings.
   
3. Click the button to import the mesh and LODs. The resulting mesh, animation (AnimSet), material(s), and texture(s) will be displayed in the Content Browser if the process was successful. You can see the AnimSet that was created to hold the animation was named after the root bone of the skeleton by default.
   

   By viewing the imported mesh in the AnimSet Editor and selecting the newly created AnimSet in the Anim tab, you can play the imported animation sequence and see that it is working as expected.

   

Individual Animations

To import animations, you first need an AnimSet to import the animation into. This can be created through the Content Browser or directly in the AnimSet Editor.

Note: Unreal Editor supports importing multiple animations contained in a single FBX file, however many DCC tools such as 3ds Max and Maya do not currently support saving multiple animations to a single file. If you export from a supporting application such as Motion Builder, Unreal will import all the animations in that file.

1. Open the AnimSet you wish to import the animation into by double-clicking it in the Content Browser or by double-clicking the skeletal mesh the AnimSet is associated with and then selecting the AnimSet in the Anim tab of the AnimSet Editor.
   
2. In the File menu of the AnimSet Editor, select Import FBX Animation.
   
3. Navigate to and select the FBX file containing the animation in the file browser. Note: You may need to set the file format to to see your file.
   
4. A progress dialog displays while the animation is being imported. Once complete, the new animation sequence (named the same as the FBX file by default) will be dislayed in the Animation Sequences list of the Anim tab.
   
   

   You can now play the imported animation sequence and see that it is working as expected.

   

Exporting Animations to FBX from Unreal Editor

Animation sequences previously imported into Unreal Editor can be exported back to an FBX file from within the AnimSet Editor.

Note: Assets in cooked packages cannot be exported as the source data which has been cooked out is required for the export process.

1. In the Content Browser, double-click (or right-click and choose Edit Using AnimSet Editor) the AnimSet asset that contains the animation sequence you want to export to open it in the AnimSet Editor.
2. In the Anim tab, select the animation sequence you want to export.
   
3. In the File menu, choose Export FBX Animation.
   
4. Choose a location and name for the file to export in the file browser that appears.
   
   A dialog appears allowing you to export the current skeletal mesh along with the animation sequence.
   
   Choose Yes to export the skeletal mesh; No to export just the animation sequence.

Resources

An example skeleton in FBX format matching the default UDK character skeleton that can be used to create animations is provided below. This skeleton also has a sample animation applied to it.

• ExampleSkeleton.fbx (Right-click > Save As...)