This guide goes over helpful information for setting up your Blender scene, building a character, and exporting that character for Unreal.

This is not a guide on how to model and rig a 3D character. This is supplemental information specific to building Unreal characters in Blender.

Scene Setup

Set Length Units to Centimeters (optional)

In Unreal, 1 unit equals 1 centimeter. It’s convenient to also use centimeters in our scene.

On the right side of the screen, find Scene Properties > Units and set Length to Centimeters.

When exporting your FBX and importing into Unreal, unit conversions will work correctly. Regardless of your chosen units, if you build your character to a human size, and it will be human-sized in Unreal.

Do not adjust the Unit Scale parameter, which is 1.0 by default. Some outdated online tutorials recommend adjusting scale in Blender and counter-acting it in Unreal. Do not do this.

Armature Setup

In Blender, an “armature” is an object containing a bone heirarchy. For your character to move, you will need to create an armature and bind your mesh to it.

Deform Bones vs Control Rig

When creating an armature for a character, there are two concepts to keep in mind:

The Deform Bones (i.e. the character’s skeleton)

  • These are the bones that you will export into Unreal.
  • Typically they all deform part of the mesh when they move (though not necessarily).

The Control Rig

  • These bones should NOT be exported into Unreal.
  • They are the controls you use to animate your character in Blender.
  • They do not deform the mesh directly – they only move other bones.

Marking Bones as Deform Bones

In Edit Mode for your armature, select a bone, and on the right side of the screen go to Bone Properties > Deform to specify whether the bone is deforming or not.

When this is checked, you’re telling Blender this is a bone you will export in the FBX.

Be careful to uncheck this box for any bones in your control rig, or else you will export them with your FBX unnecessarily.

Add a Root Bone at the Floor

A good practice that I highly recommmend is adding a root bone to your armature at the origin. As part of this, I highly recommend the origin is at the floor, and the character stands above it.

This is standard-practice in games and has numerous advantages:

  • When you position your character in Unreal, the origin of your character is perfectly aligned with the floor.
  • You can animate the entire character without moving the root bone. This avoids complications with root motion in Unreal.
  • You can add miscellaneous bones as children of the root, without being a child of the hip. Things like IK bones, or item bones, that may want to align with the world.

Shape Keys (AKA Morph Targets, Blendshapes)

You will need to use Shape Keys for lip sync and ARKit animation.

For info on authoring Blender Shape Keys, see Blender’s documentation.

Meshes with Shape Keys Cannot Have Modifiers Applied

Be careful when using modifiers on your character, because they cannot be applied on a mesh that has Shape Keys.

This is an issue, because in order for the results of your modifier to be exported, it must be applied (either manually, or during the export process).

If you need to use modifiers, you have some options:

  • Split your character into multiple mesh objects - You can export multiple meshes in your FBX. You may choose to have the head as a separate mesh in Blender.
  • Apply modifiers before working on Shape Keys - Plan ahead. Finalize your character’s mesh and apply your modifiers before authoring its Shape Keys.

Exporting Your character

Selecting Objects for Export

When exporting your character model, make sure to select its mesh(es), and its armature.

FBX Exporter Settings

To export an FBX file, navigate to File > Export > FBX (.fbx).

Next, in the dialog that pops up, choose where to export to, and configure the exporter settings.

The following are the important selections to make:

  • Under Include:
    • Limit to Selected Objects
    • Select Object Types Armature, Mesh
  • Under Geometry:
    • Set smoothing to Face - needed to export normals correctly
    • Disable Apply Modifiers - if true, may prevent Shape Keys from exporting
  • Under Armature:
    • Enable Only Deform Bones
    • Disable Add Leaf Bones
  • Disable Bake Animation

Saving FBX Exporter Preset

Blender will not remember your exporter settings between runs.

You can save presets using the dropdown at the top of the exporter settings.

Next Steps

For help importing your character into Unreal, see this page:

Importing Models

Tips on importing models into Unreal