Blender custom collision box FBX importing madness

[EL8MWKdZDqdsDyW]

I don’t what’s going on anymore. I’m trying to break down a big object from Maya into seperate pieces in Blender 4.3. I’ve recreated its collision boxes with the correct names. No matter what I do, Unreal Engine 5.3.2 won’t import it. It keeps saying “Could not find node”, or “Could not find geometry”. I’m not sure what I’m doing wrong as I was doing what several Youtube videos are showing for bedim.

Here’s screenshots of what I’ve done:

I selected all objects for import

This is the setting I have for exporting:

It always ends up like this now:

Anyone knows what’s going on? I can only use Blender right now.

[brs-sebascova]

Hello there @EL8MWKdZDqdsDyW !

Yeah, sending assets between UE and Blender can be a headache.

For these cases, the usual approach is reset export/import settings in both UE and Blender, and to make sure that any transforms and/or modifiers are implemented before transfer, which I believe you have already covered (please double check, just in case).

I would suggest trying the following addon for Blender, which eases the transfer process, and gives you a bit more of control over it. Please check the link below:

GitHub - xavier150/Blender-For-UnrealEngine-Addons: I have created this addons for export asset from...

[EL8MWKdZDqdsDyW]

Thanks for the info. I haven’t done anything to the export/import settings for both programs, so they’re fine. Here’s what I have for Unreal Engine:

Screenshot 2026-01-20 163038679×1183 64.8 KB

Screenshot 2026-01-20 163057694×1176 79.2 KB

Even pasting the FBX into the content section of the project folder didn’t work. It would “pretend” that it did, but the mesh and its materials never show up in its new folder.

The only thing would be that the piece and collision boxes has history on it from being moved around. I can’t figure out how to erase their transformation history on Blender.

Also, where do I download that add-on you’ve mentioned? I’ve gone to the link, but I don’t know what to click on.

[EL8MWKdZDqdsDyW]

I’ve figured out why the mesh wouldn’t import. When I selected everything on the collection section, it didn’t select the mesh with everything. So that problem is solved. Now I’m trying to get the collision imported correctly, cause it’s not reading them now. All I get is a giant box.

[EL8MWKdZDqdsDyW]

The collisions keep coming out like this:

instead of this:

[brs-sebascova]

Hello again!

Glad you could fix the initial problem. Now, for the collision to correlate exactly how they look like in Blender, we have to check a few more parameters.

From your original post, you are using the proper naming convention for collision pieces, so that’s covered (UCX_assetName_01, and so on). Now, when exporting from Blender, please make sure that you select ALL the assets involved, the entryWay and its coliisions. Then, limit said export to the Selected Objects, and make sure you set Apply Scalings to FBX All (which should avoid deformation in the boxes).

Now, from UE, it should look like this:

Specially the “Import Collisions According to Mesh Name” check, as it governs the prefixes you are using:

And make sure no settings are enabled to generate missing collisions (these should not even be available in the first place, as your transfer includes collisions, but double checking is always good).

Once completed, open the asset in editor, click the Eye icon, and enable “Show Simple Collision”. If what you see is a green wireframe box, that’s UE generated collision, meaning something went wrong during transfer. Instead, if you see green shapes matching your Blender setup, then you are good.

You can also play around with collision complexity inside your asset, try changing it to “Use Complex Collision as Simple”, and check if it alters the box.

[EL8MWKdZDqdsDyW]

Hello again. I’ve tried your advice, but things went haywire. First off, selecting “Apply Scaling’s to FBX All” shrunk the object to marble size:

Second, I can’t find the “import Collisions” options, or the other options in your picture on Unreal Engine. I’m not sure if it’s because I’m using version 5.3, the options weren’t there:

Maybe I’m looking in the wrong place as this is the static mesh menu. Any ideas?

[brs-sebascova]

That scaling conflict is strange, it’s possible that the original scale of the asset in Blender did not match what you already had in Unreal. I would try increasing it’s size in Blender to compensate.

As for the missing “Import Collisions” options, I replicated the scenario using UE 5.7. A lot has changed since 5.3, so it’s likely that the options are somewhere else in the menu. From your screen, check under “Collision Presets” and “Advanced”.

I would suggest, if possible, testing the Blender import with UE 5.7 as well, a lot has improved since then (both still have a rocky relation, but it’s a bit better nowadays).

[Countsie]

That Import Collision option is in the Import Dialog, not the Details panel. I don’t think it’s like that for 5.3 though, the import flow has had some major revamps since then. You may want to uncheck ‘Generate missing collision’ in your import dialog, although that’s likely not the actual issue.

Your naming looks correct, but I’m confused as to why your entryWay is an empty with no vert data in your initial blender screenshot.

For static meshes, I don’t do any scaling of blender scene, or export settings, only change to Export is ‘selected objects’, ‘mesh’ and geometry smoothing ‘Face’.

You could open console (~) and type ‘Log LogFbx VeryVerbose’ to see if it spits out any useful info to the output log when you do an import.

Something else maybe: check your normals are facing the correct direction on your collision shapes. In Blender “Viewport Overlays” icon top right of 3d view ->Geometry → Face Orientation. They should show all blue, no red.

[EL8MWKdZDqdsDyW]

You’ve fixed it. It was because the “Show Import Dialog at Reimport" wasn’t enabled in Editor Preference. I’ve enabled it, reimported the FBX, and the collision boxes were there. Thank you very much. Also, I have tried the “Face Orientation” you’ve mentioned and aside from the parts that can’t be seen in the scene, the rest are blue.

[EL8MWKdZDqdsDyW]

I should have guessed as much. I’ve never bothered with the newer versions of Unreal Engine because of a Pricing Options pop up whenever I tried to download them onto my launcher. I’ve never seen this for previous versions, including 4.27. I can always give 5.7 a try and see what happens. Mostly it’s because I thought updating the engine whenever there’s a new version isn’t always necessary. Even more so if it removes things I need, like “Movie Legacy”. I use that method a lot and was never a fan of the alternative.

[EL8MWKdZDqdsDyW]

Never mind. It went back to the original problem with the other pieces.

I don’t know what I’m doing wrong. I’ve used the same method:

even without enabling “missing collisions” part, it still comes out like this. I don’t remember what I did with the entryWay that fixed it.

[Countsie]

I’m thinking your problem is on the export side.

Combine all your visual static meshes manually before exporting. Combine into a single mesh object ‘entryWay’ (blender select all mesh, ctrl-J). If you have everything inside that Empty parent and are combining meshes in unreal import that may be your problem because the names of the meshes wont match the UCX name.

If that doesn’t work:

Try exporting just the collision as a separate test mesh to make sure it’s importing/showing properly.

Try a super simple scene, a like a ‘cube’ and ‘UCX_cube_01’ and see if you can get that working, and build from there.

[EL8MWKdZDqdsDyW]

Good news. I’ve figured out what happened. For real this time. I have been doing “All Transforms to Delta” (Ctrl + A) whenever I moved an object. I didn’t do it for the fifth literation of my second floor, and it worked:

THAT was the problem this time. I noticed it when I imported a cube, like you’ve said to try, and I didn’t do that action. I’ve imported it, and it worked. So, I did the same thing here. This is what happens when one is more used to Maya than Blender. The knowledge starts to bleed into each other. Thank you for your help in this.

[EL8MWKdZDqdsDyW]

I take it back. Now the collision boxes are not showing up at all. It did for a few minutes, and then when I added something new, they just disappeared. Now I can’t get them to show at all:

I’m at my wits end with this. I’ve uploaded one of them to this reply. Maybe you can figure it out on your end.

L.B.Section_01_secondFloor.fbx (301.9 KB)

[Countsie]

It’s because you have your mesh as a child of an empty. the empty is named L.B.Section_secondFloor, your mesh is L.B.Section_secondFloor.001

To fix:
-shift-drag your L.B.Section_secondFloor.001 mesh object out of the L.B.Section_secondFloor empty object into it’s enclosing Collection(“folder”)

-delete L.B.Section_secondFloor empty object

-rename L.B.Section_secondFloor.001 to L.B.Section_secondFloor

-select select mesh and collision objects, export fbx

should work now. not sure why you had this empty. actually brought it up in my first post.

Edit: For clarification ‘Empty’ is a type of object in blender used to contain objects/transform data usually, maybe it’s a called a null in Maya? That’s not really clear if you don’t know, esp how I worded it above.

[EL8MWKdZDqdsDyW]

So THAT’S what you were trying to say. I’m a complete novice when it comes to Blender. I’m mostly using it as a free alternative when I can’t use Maya Creative. In that program, one has to group the mesh and its collision boxes before importing it into Unreal Engine.

Here’s how I did it there:

1. Create a group named after the 3D object. So, in this case “secondFloor”.
2. Drag the 3D object of the same name into that group, along with its collision boxes.
3. The collision boxes are turned invisible before exporting so they won’t show up.
4. Make sure their history is erased. Like moving them or resizing them. Freeze their history.

That’s about it.

So, in Blender, the Maya FBX with its group became a parent child thing. With that mesh becoming empty. That makes some sense. Now when I shift+drag the mesh out of its “group” the entire mesh grew in size and rotated into its back. I had to import another FBX if itself to resize it its original size. Is there a way to prevent that?

[Countsie]

Makes sense. Try changing your fbx import scale to 0.01. You may be able to just Ctrl-A and apply the transforms to the empty or it’s children before you do the dragging. Or, you may end up having to rotate imports by hand. Hitting ‘r’, ‘z’, ‘180’, ‘Enter’ is pretty quick. Just have to test it, play around till you find what works for your situation.

Take copious notes (you will need them later when you need to revisit your source files), and build a workflow you are used to for import/modify/exporting them. I use a ‘Scripting’ Workspace in blender to take notes within the blend file itself.

All the DCCs have issues moving fbx files around in one way or another. Blender is a beast and super capable. Not much you can do in Maya/3dsmax/c4d you cant do in Blender. Stick with it, it’s worth it.

Also, for future ref, .gltf and .usd are two other pipelines you can use to move data to unreal if .fbx proves too problematic. I don’t think it would have solved any of this but ‘more than one way to skin a cat’.

[EL8MWKdZDqdsDyW]

Okay. I did what you’ve said to two pieces, and it worked. The size changing was fixed by using 0.01 on the object, and the collision boxes are there when imported to Unreal Engine. This should be everything sorted now. The only reason I’m using Blender in the first place was because of a texture mishap that seems to be fixed by breaking down the gigantic piece. Better using Blender for the small fixes than buying more tokens (though that in and of itself is still preferable than buying its four-digit subscription service). It’s too bad that most companies prefer Maya or 3D Max anyway. So, the experience and projects made with it is still worthwhile. Thanks for your help again. I’ll keep this page bookmarked for future problems.

[Countsie]

Look deeper into recent info on Blender in production. I’ve seen stats lately of a lot of studios using it in their pipeline. Depends on use, I think Maya is still the king for animation. The skills in Blender transfer to the other DCCs pretty easily anyways, they all copy each other’s homework.

Glad you got it fixed!