[Epic Official] FBX Import Reporting

Hey Evenios -
Thank you for your report. Can you please upload an asset that caused this crash so we can investigate further?

Hey iniside -

Thank you for reporting. I tried importing the 2 fbxs you uploaded and in both cases the vert count is exactly 1058. If you could upload the max file you were working on, I will continue to look into this issue for you.

It was actually modo that caused issues not max version. But seems like in 4.1 version the issue is no longer present.
As I get correct amount of verticies when I reexport and import mesh again.

Hey Mysticeti -
Your are on the right track getting your model into the engine. ImmortalEmperor seems to have fixed the model import issue by reversing the normals. The black mesh is the engine looking for a second UV unwrap for lightmapping. You can try to go into the Static Mesh editor and then change the Light Map Coordinate Index to match your unwrapped UV layout, or go into a modelling program and generate a 2nd unwrap on a different channel then re-import the model, again checking to see if the Light Map Coordinate Index is set to the correct UV layout Channel.

Hi Eric,

ImmortalEmporer was a big help, yes. I’m still unsure why ticking the “Invert Normals” when I imported the FBX didn’t work though.

Most of my problems stem from assuming that because the import succeeded the asset would work without issues. I’ve been disabused of that notion as things (obviously) aren’t that simple: On Noobs and UV Lightmaps - Feedback for Unreal Engine team - Unreal Engine Forums

When I import an FBX file exported from blender with multiple objects the following happens

A: All object origins are at the center of the object set, instead of the origin of each object
B: Lightmaps are broken on all objects except for the first one.
B.1: I have to manually edit each asset and set its lightmap settings in the static mesh editor.

The zip file linked from the wiki contains:

  • broken FBX file
  • Blender .blend file
  • export screenshot
  • import screenshot

Here is the link to the zip file on the wiki

Hi, I’ve taken a look at your mesh and I am able to import it properly with the collision. For this to work, please make sure you do NOT have "One Convex Hull Per UCX checked in the Advanced Static Mesh options on import.


Hi My FBX problem is to do with Cinema 4D - UE 4.1 is flipping Y-Up to Z-Up perfectly and its working for animations etc. BUT meshes are coming in Y-Forward when ideally they would be X-Forward/Y-Right.

In C4D - Z Forward/Y-Up

In UE4 Z-Up/Y-Forward

Link to files


I totally have this issue too. Can we have an option in the importer to add a global rotation to the mesh around the X, Y and Z axis? This would solve this issue.

Hello, im having issue with vertex color in FBX file. In blender im see my color, but after import color is wrong.

FBX file https://dl.dropboxusercontent.com/u/26664093/mushroom_vertexcolor_problem.fbx

Problem in Gamma Correction, pow(x, 2.2) fix that problem.


Thank you for your patience. I was able to get errors and a lock-up when importing it with those options, but not a crash. I was able to get around them by not check the Import Rigid Mesh option, as that is for skeletal meshes without bones. I still saw bind pose issues, but those are known and being worked on. At what point in the import do you crash and what is the callstack?

Hey master_rigel -

A: The origins of any model when importing to UE4 is always (0,0,0) in the editor. So if your object is off the center point in Blender, the object’s pivot in UE4 will always be off by the same amount.

B: These questions I need clarifications for. The assets I imported only have one UV channel which is ok, but if you are combining the meshes (which is what your import settings show) the objects will need to be unwrapped as a single unit so no UV islands are overlapping. Now, when I import the FBX as separate meshes, most of your UVs are ok even if they need a little padding between teh UV islands. There are a few where the unwrap is out of the (0,1) space which will cause errors.

Examples: (red lines mean out of bounds) and no islands should be overlapping

UE4 correctly imports FBX files with multiple animations, but when those animations are reimported, they are overwritten with the first animation in the file rather than the correct animation.

The file is created in blender 2.7 and exported to FBX 6.1 ASCII with the updated plugin, and that is converted to FBX2013 with the autodesk converter tool. The animations appear correct in the FBX viewer.

To reproduce:

  1. Download and extract this FBX
  2. Import as Skeletal Mesh and include animation.
  3. UE4 will create the animation assets correctly the first time.
  4. Open the run_cycle animation and reimport it.
  5. The run_cycle animation will be overwritten with the wiggle animation.

Hi The Beej -

I can confirm you are correct there is an issue with reimporting the animations from a single fbx. We are working on a solution, but I have no timeline as of yet. We are also currently tracking down possible Blender/FBX import issues and want to ask if it would be possible to get the original Blender file for you animations?

-Eric Ketchum

My apologies, this zip contains the source .blend and exported .fbx.

I dug around the source, and the bug is on line 182 of SkeletalMeshEdit.cpp, the index should be chosen for the animation but is instead always 0 (the first animation). By changing this constant I was able to change which animation overwrites the current animation on reimport.

I made a pull request on github that fixes this bug.

I second the request for LOD naming rather then the specific Maya lodGroup method. Using C4D here. In Unity we just use _LOD0, _LOD1 on the meshes or nulls

For more compatibility with other DCC apps, it would be much better if UE found lodGROUP1, lodGROUP2 as parent objects or even easier, add support for _LOD0, _LOD1, _LOD2 etc.

Then we can do stuff like this




UE could do its combiner magic on each LOD and assign the correct objects to the right LOD slot.

PS this is how it works in Unity, its a very convenient way of doing things.

Indeed, the Unity way is very easy and fully automatic. Also, the compatibility with it would be awesome. I could convert all my assets in no time from one side to another! There is no standard for colliders perhaps, but still it could be a great help for artists.