Physics Asset Box Extents reading in Meters instead of CM (Blender FBX Import Scale Issue)

Ronniiyyy
Fri, 13 Mar 2026 14:03:55 +0000
World Creation

UE 4.26

Hi everyone, I’m running into a frustrating scale mismatch between my Skeletal Mesh and my Physics Asset, and I’m hoping someone can point out what I’m missing in my Blender-to-UE pipeline.

My Setup:

I rigged a custom vehicle in Blender.

My units in Blender are set to Metric / 1.0 Unit Scale.

I applied all transforms before parenting the mesh to the bones (Both the Mesh and the Armature have a strict Scale of 1.0, 1.0, 1.0).

The Problem: When I import the FBX into Unreal Engine, the Skeletal Mesh looks perfectly fine. It sits in the world at the correct, realistic size.

However, when I open the Physics Asset, delete the default capsules, and create a new Box Collision around my vehicle_base bone, the scale is completely wrong.

For example, my vehicle is physically 3 meters wide.

In the Details panel for the Box shape, the Extent values show up as 3.0 instead of 300.0.

It seems the Physics Asset is reading the raw Blender meters instead of converting to Unreal’s native centimeters, which causes my vehicle to behave erratically (like flying or floating) when I simulate physics.

My Question: Why does the visual mesh scale perfectly, but the Physics Asset primitives are scaled down by 100? Is there a specific FBX Export setting in Blender (like Apply Scalings: FBX All) or an Import Setting in Unreal that I need to check to force the bones/physics bodies to recognize standard UE centimeters?

Thanks in advance for the help!

2 posts - 2 participants