Blender is a general-purpose, free and open source 3D package. It is also very popular among VTuber creators.

This page goes over things you should know when using it for Unreal.

Coordinate System Differences

Blender uses a right-handed coordinate system, whereas Unreal uses a left-handed one.

With default exporter/importer settings, basically think of it as the Y-axis flipping in Unreal.

For the most part, you can ignore this discrepency. Default FBX exporter and importer settings will convert coordinate systems correctly.

Bone Differences

Blender’s bones are fully compatible with Unreal, but they are represented differently.

Blender Bones

  • Consists of a head and a tail, with a shaft in-between. The bone’s origin is at the head, and it is oriented such that the Y-axis of the bone points toward the tail.
  • In a heirarchy, they can be either connected or disconnected.

This example shows 3 bones. Bone1 is the root, and Bone2a and Bone2b its children. Bone2a is connected, and Bone2b is disconnected.

Unreal Bones

  • Represented by a single point, with any orientation.
  • In a heirarchy, shafts will be drawn between a parent and its children.

Yes, this is the exact same skeleton as above.

Even though Bone2a and Bone2b don’t have a shaft drawn, they work identically to the Blender skeleton.

You’ll also notice the flipped Y-axis, due to Unreal’s left-handed coordinate system.

Exporting from Blender with “Add Leaf Bones” (Bad)

DO NOT USE THIS OPTION. This section only exists because it's a common point of confusion.

Blender’s FBX exporter has an option to “add leaf bones”, which is enabled by default. What this does is add extra bones to the ends of the skeleton.

This is what the same skeleton above looks like in Unreal with “add leaf bones” enabled:

Do NOT use this option when exporting for Unreal. This adds extra unused bones to your skeleton, which is wasteful and confusing.

Remember to disable this option when exporting your character model.

Notable Blender Plugins

Blender has many plugins available for download, some free and some paid.

You don’t need any plugins to get started, but these are plugins I have opinions about (good and bad).

I do not recommend using the official Unreal Blender plugin.

With my art pipeline I have complex characters, with many animations spread across different files. I produce Blender animations and export assets for multiple game engines. I found that Unreal’s official plugin is intrusive and inflexible, and thus I do not recommend it for character production.

Your mileage may vary, however this documentation will not touch on it further.

Blender Rigify

Some online tutorials may mislead you into thinking Rigify is required to rig characters in Blender. This is not true. Rigify is an optional tool that is a layer on top of Blender's actual rigging tools.

Blender has a built-in plugin called Rigify, which is a tool to more quickly rig humanoid characters.

I personally do not like this plugin, but I am admittedly a power-user with a custom rig. I understand that it many people may find it useful, especially beginners.

Ultimately, it’s free, and kind of messy.

Auto Rig Pro

If you want a great rigging tool, and a great FBX exporter, I recommend purchasing Auto-Rig Pro.

Also note that this plugin’s FBX exporter is excellent, especially for managing animations.

Next Steps

Blender - Building and Exporting Characters

Helpful info for building a character in Blender and exporting for Unreal