4.10, model shading incorrectly

so I’ve been agonizing over this pelvis topology trying to make it perfect. I think I’ve finally found a decent compromise between a perfect shape and a reasonable level of detail. I made the model in Blender, and because blender’s shaders are crap, I threw it into unreal engine to get a good look at how it would actually appear in the engine.

Aaaand there’s a problem. The polygons aren’t shading together properly.

This problem seems to vanish when the camera is about 3 meters away or so, but I want the player to be closer (approx. arm’s reach).

I imported this as a static mesh, and then as a skeletal mesh running an animation asset. The problem persists in both. I’ve made a fully rigged model before and did not have this issue, but that was in 4.5 or 4.6. Somewhere around that time. I saw another answer suggest turning on “recompute normals” but doing so causes each triangle to shade flat. Anybody have any solution to this?

edit: this problem does not appear in persona or the mesh viewer, only in the level editor.

Apparently building lighting fixed this problem. I’m curious why this is.