Morph targets cause meshes with hard shaded edges to shade smooth

After importing a low poly, hard shaded mesh into UE4 with morph targets which work well, the flat shading on the mesh gradually transitions to soft or smooth shaded edges as the morph target’s value is increased. I am using blender and the mesh does not have an armature. In Blender, the edge split modifier does not seem like a viable option as it is not permitted to apply the modifier if the object has shape keys, and if pre-applied, causes future problems. I have also tried setting the edges and faces to force flat shading in blender to no avail. In UE4, I have tried importing with each shading method, sporadically testing the “Preserve smoothing groups” checkbox also without success. MikT Space always causes the smoothing transition, and while the Built-in does preserve correct smoothing, it instead causes some vertices and faces to be unaffected by the morph target.

I think I have found a good fix for morph target shading and shadowing problems, at least that work with my meshes. The only import option that preserves edge shading and does not seem to create weird shadows is the “compute normals” on the “Built in” method. The problem is that, this option causes face tearing frequently which I was able to fix in Blender by pre-triangulating my meshes. To do this in Blender, I create a duplicate of my object, delete the morph targets on the original and apply a triangulate modifier. Then on the duplicate, I select the shape key I want to transfer, shift select the original, and using the down arrow in the shape keys panel, select “transfer shape key.” Each shape key is transferred separately and the duplicate is deleted when done.

I have also created a basic setup video where I explain this, hopefully better, along with other things I’ve found when working between Blender and UE4, here is the link if anyone is interested, because the video is kind of long, 8:00 is when I show the morph target problems and 11:00 is when I apply the pre-triangulation fix in Blender:

if anyone is still searching for an answer, this is what worked for me.

i wanted to import a low poly model, mine craft character rig, into unreal engine and was having issues with morphs and blend shapes… i used blender to export FBX, settings of the export that worked for me are shown in the image below:

if anyone is still searching for an answer, this is what worked for me.

i wanted to import a low poly model, mine craft character rig, into unreal engine and was having issues with morphs and blend shapes… i used blender to export FBX, settings of the export that worked for me are shown in the image below:

link to the image!