How to import LOD's as ONE fbx (Blender)?

How do I set it up in Blender so that the base-mesh and LOD’s are all in one single FBX-file? How must I name the models so that UE4 will recognize them as LOD’s?

I know how to import a base-model and then import the LOD’s seperately in UE4 but it is kinda error-prone and a pain later to maintain so I prefer to have them all in one FBX-file. All the resources/tutorials I could find are sadly all about this including the official documentation but do not explain how to do it as one FBX-file.

I found LOD-group for Maya here: https://docs.unrealengine./latest/INT/Engine/Content/FBX/StaticMeshes/index.html but there is no such thing in Blender? Also I suppose that just pressing ■■■■+g (creates new group) and naming it “LargeProps” will not be sufficient.

Have you looked at this?https://wiki.blender.org/index.php/User:Kupoman/Level_Of_Detail
Honestly I havnt looked into this yet, like you I have been exporting LODs seperate and setting them up in unreal. I havnt had problems with it though. Let me know how this works out.

So I added the LOD’s in Blender (they work when zooming in/out in Blender). I exported it as an FBX and imported it into UE4 with the options as shown below.

But in UE4 I have no LOD at all and I end up with 3 seperate meshes after the import:

89819-bp3.png

89820-bp4.png

I tried importing with the “combine meshes” option. Now I have a cube but still no LOD and the cone and cilinder are gone.

I think that the problem is that UE4 somehow needs to know that the other 2 objects are LOD’s and not meshes. But I can’t find any documentation on how to tell UE4 that.

I am not an expert on LODs and how they work exactly but it makes sense to me that unreal reads them as meshes because that is what they are. It is the same mesh with a different number of verticies so that at a distance it only loads a lower poly mesh because you don’t need a lot of detail at a distance. It is only to save on memory and increase performance.

To me it does not make sense because when it imports LOD’s as meshes (instead as LOD’s) then those meshes can NOT be used as LOD’s… Because meshes in UE4 can not be used as LOD’s. You have to use the manual import-button instead.

So does this mean that UE4 does NOT support LOD’s ‘baked’ into the original mesh from anything but Maya? Am I forced to always manually import them into each mesh in the mesh-editor in UE4?

Hi. After researching many FBX files exported from Maya and Max I found the “easy” fix to this issue. Basicly you parent your objects to an empty and that empty has to be descirbed as LODGroup in FBX file. I made a change in Blender’s FBX binary export script (just 3 lines) but I hope it can get somehow in the official release… but for now here is a video showing the whole proces + fix

Hello Pavel,

I am facing the same problem at the moment and found your solution to it. However I also found the blender developer page on which you submitted your fix and it looks like it was implemented into blender on Oct 31, 2017. However I can’t find any documentation on how to make use of this feature in blender.

Do I still need to apply your fix to the script file manually?