UBX_ from Blender to UE4


what export pipeline from blender collisions (UBX, UCX, USP) to unreal editor do you use ?

I tried, Blender Tools, Batex and the builtin blender export FBX

…nothing works for collisions ( I keep having errors, node not found, stuffs like that)

and blender tools (send to unreal) is not even able to export skeletons anims anymore

so just wanted to know how you guys were managing to do that…


Proper naming.
But I also use my custom plugin like all the time, so idk or remeber if there’s anything special going on with it.

The UBX/UCX etc. Usually just need to follow proper nomenclature.

I’ll attempt to plug in a screencap of an example from the PC in a few minutes.

And the export

To export collisions you should:
-For colisions boxes name the mesh UBX_meshname_## where ## is the number of the collision box and meshname is the name of the mesh you want to add collisions
-For irregular collisions name the mesh UCX_meshname_##. The mesh must be convex
-Make the meshes childs of your mesh object

This should work.
This is explained in the documentation in the FBX section.

I made a small addon for Blender to handle renaming.

UBX is strictly a EDIT: rectangular prism, USP is strictly a sphere, UCP is strictly a capsule. UCX is for convex shapes, which will likely be most of what you’re doing. If the collision shape is non-convex you need to split it into more collisions meshes until it is.

I use Blender tools, but those tools do use the default FBX exporter.

Here’s the documentation:

Those are mostly UBX - but they are convex since the inside is smaller then the outside.

Anyway, my plugin exports this just fine.

I usually have super complex files, some of which include LODs

Built in FBX export : it does not work, the generated collision wraps the whole object instead of importing the small box I created


I tried to find a software to list the content of the exported fbx, if anyone knows one …

so far FBX review and FBX exporter (both from autodesk) just display the model

Did you applied transforms to the mesh and the collisions in blender?

I dont see how it is related but yes, all transforms are applied

the problem is that I dont see in the static mesh editor a list of my collisions the could assert the import did work

I now have 4 collisions

with the FBX export, only one collision

with batex too

I’ll check this one, could be handy indeed :slight_smile:

[edit] tried to install your addon but it does not appear, how do I use it ?

You mentioned this, so I thought it was importing but was too big, but I think I know what you mean.

I’m not sure you can have more then 100 collisions. The documentation refers to XXXXX_## and not 3 digits for the number of the collision.

I have 4

it does not work at all, anyway static mesh editor does not seem to handle external collisions anyway, it creates its own simple/complex collisions

I’ll have to create the collisions manualy

Yes, but you have this:




Create a folder called ue_collision_renamer, put the “init” file there, and put that folder in Blender/version/scripts/addons

I don’t think it installs “normally” from outside because it’s just the .py file.

ok it is installed


and indeed, it’s only 2 digits


If you can’t get this to work, let me know. I’ll create a sample working file and send you so you can try it and see what’s different in yours.
I know this works because I use it all the time.

2 digits was the trick…now UE4 proposes me to import the collisions

but I dont see them in the static mesh editor :frowning:

Here’s a working example:

sphere.fbx (32.7 KB)
sphere.blend (847.2 KB)