This document discusses Blender specific FBX pipeline issues. The UE4 FBX pipeline in general is covered by Epic's documentation in FBX Content Pipeline.

FBX files can be used to exchange data both ways: from Blender to UE4 and from UE4 to Blender.

Blender can author and export static meshes, skeletal meshes, animations, and textures.

Skeletal Meshes

Import Normals

When importing skeletal meshes, it's important to choose Import Normals from the UE4 FBX Importer. Otherwise, UE4 will compute smooth normals and you will lose any hard edges authored in Blender.

Here is an example of a 2 ico spheres, the top smooth shaded and the bottom flat shaded, and an armature in Blender:

Skeletal Mesh with Smooth and Flat Shading.png|Skeletal Mesh with Flat and Smooth Shading Mesh Compute Normals from Blender Authored FBX.png|Result using Compute Normals Mesh Import Normals from Blender Authored FBX.png|Result using Import Normals

Here is the result in UE4 using Compute Normals:

Here is the result in UE4 using Import Normals & Tangents:

Armature Name

When adding an armature, Blender will name the object Armature. There is a hack in UE4's FBX importer that looks for an object named Armature and then does special processing that can lead to scaling problems when importing animations. If you want to avoid this special case processing, simply rename Armature to something else, like Root.

This is also mentioned by Blender to Unreal Engine with Matt Workman.

Mannequin Compatible Rigging

Jim Kroovy's Blender to UE4 - Mannequin Compatibility Explanation video discusses some of the technical details required to make an animation rig in Blender export a skeleton and produce animations that are compatible with UE4's standard mannequin model.

See Also

• FBX - Blender Manual
• FBX Content Pipeline - UE4 Documentation
• Blender FBX Known issues & TODO's
• UE4 Blender Example Project - demonstrates skeletal and static meshes, animations, mannequin animations, and using Blender to blockout levels