Importing objects from Maya

Unity natively imports Maya files, supporting the following:

• All nodes with position, rotation and scale; pivot points and names are also imported
• Meshes with vertex colors, normals and up to 2 UV sets
• Materials with texture and diffuse color; multiple materials per mesh
• FK & IK animation
• Bone-based animation
• Blend shapes

Limitations

Unity does not support Maya’s Segment Scale Compensate setting on joints.

Requirements

You need to have Maya installed to import .mb and .ma files directly into Unity. If you don’t have Maya installed, use the .FBX format instead. For more information about importing FBX files, see Importing models.

Behind the import process

When Unity imports a Maya file, it launches Maya in the background. Unity then communicates with Maya to convert the .mb file into a format Unity can read.

The first time you import an .mb or .ma file into Unity, Maya has to launch in a command line process. This can take a while, but subsequent imports are very quick.

Export settings in Maya

Blend shapes (morphing)

When exporting blend shapes from Maya:

• Apply the blend shape to the export mesh with its targets in order.
• If you require Maya animation keyframes, you can animate keyframes on the blend shape node.
• Go to Animation > Deformed Models > Blend Shapes and select the FBX Export option in Maya before exporting the mesh.
• If you also want to export skin deformation, go to Animation > Deformed Models > Skins and select the FBX Export option in Maya before exporting the mesh.

Import settings in Unity

Using IK to animate characters

When you’ve imported the .mb file into Unity, select it in the Project window and enable Bake Animations in the Animations tab of the Model Importer.

Tips and troubleshooting

• Keep your scene simple: only export the objects you need in Unity when exporting.
• Unity only supports polygons, so convert any patches or NURBS surfaces into polygons before exporting; see Maya documentation for instructions.
• If your model did not export correctly, the node history in Maya might be causing a problem. In Maya, select Edit > Delete by Type > Non-Deformer History and then re-export the model.
• Make sure you’re using the latest FBX exporters from the Autodesk website.
• The Maya FBX Exporter bakes un-supported complex animations constraints, such as Set Driven Keys, in order to import the animation into Unity properly. If you are using Set Driven Keys in Maya, make sure to set keys on your drivers in order for the animation to be baked properly. For more information, see the Maya documentation on Keyframe Animation.
• In Maya, the visibility value is present on each shape but can’t be animated and is not exported to the FBX file. Always set the visibility value on a node and not on a shape.

• 2018–03–12 Page amended