Importing

You can import files into Unity by copying them anywhere in the Assets folder of your project (which can also be done by dragging and dropping them into the Project window). Then you can select the imported asset in the Project window and use the Inspector to view and edit its Import Settings.

Model

The Unity Manual explains the settings in the Model tab, but they are not directly relevant here.

Rig

The first thing you need to do when you import a model is go to the Rig tab and set the Animation Type to either Humanoid or Generic:

Humanoid Generic
The character must have a specific set of bones explained in the Unity Manual (some are optional) and Unity will then be able to play any Humanoid animation on that character using its Retargeting system. The character can have any bone hierarchy, but a Generic animation can only be played on the specific hierarchy it was built for. This also makes Generic animations better for performance than Humanoids.

Mixamo can also retarget its animations to any character before you download them, allowing you to save performance by using a Generic Rig in Unity.

The remaining options for a Generic Rig should generally be configured as follows:

Option Selected Reason
Avatar Definition Create From This Model You generally want the character model to define the bone hierarchy that all the animations will use, but if you are using the same Rig in multiple characters or if you are importing animation files separately from the model you can use Copy From Other Avatar instead.
Root Node Hips Only in Generic Rigs. You generally want to use the topmost bone in the model's hierarchy as its root. If you are not going to use Root Motion to move the character, setting the Root Node to None will improve performance according to Unity's Animation Optimization guide.
Skin Weights Standard (4 Bones) See the Unity Manual for details about this setting.
Optimize Game Objects Enabled Improves performance by not creating a Transform in the Hierarchy for every bone in the character.
Extra Transforms to Expose Right Hand If you want to be able to access the character's bones at runtime such as to put a weapon in their hand, you need to select the bones to expose (so that it can exclude them from the Optimize Game Objects setting).

Animation

A character model downloaded from Mixamo will include some empty animation data which we do not want, so you can simply deselect Import Animation in the Animation tab.

The Unity Manual explains how to use the Animation tab when the file actually contains animations that you want to import.

If you import an animation separately from a model:

  • You must set the Animation Type in the Rig tab to match the type you selected for the model:
  • If you are using a Generic Rig without Root Motion, you can leave the Avatar Definition set to No Avatar.
  • Otherwise you should probably use Copy From Other Avatar and select the model's avatar. Or if you want to configure it differently for this animation you can use Create From This Model.

Materials

Mixamo embeds the character's textures inside the FBX file, but in order for Unity to use them you will need to go to the Materials tab and use Extract Textures... to save them somewhere in your project (the folder containing the FBX is often a good place, or you might want to create a Textures folder).

If a NormalMap settings window pops up explaining that a texture is being used as a "normal map", simply click the Fix now button to set its import settings correctly.