SkeletalMesh LOD Morphing

I have a character with multiple LODs each with the same morph targets shaped for that LOD.
How can I go about importing this correctly. I import the base LOD and that come in with morphs, I will then try to import LOD 1 and it doesn’t work with morph targets with the same name, or import ones with other names.

How do you handle this correctly? I’m not sure what’s going wrong.

Should the morphs have the same names?
That would certainly be logical to use them.
In my file they are currently prefixed 0_morph1, 1_morph1.
I could try changing things but I don’t think that’s the issue.

I have tested adding morphs using the same name throughout but only LOD 0 is effected.

Really confused here, having to work with highest LOD only now till I can figure out how this is supposed to work.

I’d like to know the answer as well :slight_smile:
When you imported the lods with different morph names, were you able to use them?
I wonder if we can get information in the animation blueprint about the lod currently active and selecting an animation/morph target accordingly.

I thought of using my own LOD system, it doesn’t seem to work with different or same names.

I even tried exporting 2 models with identical shapekey lists.
Only the base LOD morphs.

I’ve got it working now! Ok so what you have to do in maya is create two blendshape meshes; One for lod0 and one for lod1. Makes sure you give them the same name. In maya its only possible to give two meshes the same name if they are not in the same group or both not in world space. (see image outliner)
Create the blendshape deformers. Create the lod groups as shown in the fbx skeletal mesh pipeline doc. ( select lod0 then lod1. menu->Edit->level of detail-> group) Bind the meshes to the skeleton (can be done at any time). To export make sure you select the lod group AND the meshes in it then the skeleton’s root and export. In the fbx export settings make sure animations is checked and deformed models and skins and blendshapes. Now go to UE4 and import. Make sure you check ‘import morph targets’ and ‘import mesh lods’. Now with one slider you control both meshes their lods.

Let me know if you have any trouble and if you get any error messages.

Thanks for the suggestion, I’m using Blender though, that doesn’t have the Maya LOD group feature, I will try naming the models the same, and anything else I can think of, but I came across the LOD Group option in docs, but not aware of equivalent in Blender, so I have to use the import LOD option after importing the base mesh on 2 different fbxs.

There is a multires modifier but that only works on subdivisions, my LODS can’t be applied as they have different vert counts.

yeah that’s annoying. But there is another way to do it. Export your LODS as separate files. First import the highest detailed mesh in UE4. Then you can manually import the 2nd LOD in the mesh tab under Lod setting-> Lod import-> drop down: import lod level 1. As long as the blendshapes have the same names they should work with the same slider.I got it working like that as well.

Thanks for the help, I might have only tried import with the base as the lowest…Maybe that was simply the problem.
I have also seen there is a naming convention when importing all LODs something like Base_Model, LOD1_Model. Something like that might work as well.
I’ll try some more things soon, still having to rework assets by the looks now, but that stage will be coming up again, if I ever can finalize my character assets that is…

Hey Triplelexx, just checking if you managed to get this to work with Blender.

I tried everything I could think of and I still can’t any morph weights to affect LOD1 or LOD2 - morphs work only on the Base LOD for me.

Just figured this out! If anyone is trying to figure out how to apply Morph Targets to LODs in 4.26 or higher, go to the mesh LOD build settings, and after you have your LODs built, go to each individual LOD and check off Remap Morph Targets, and then regenerate LOD

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