Runtime Distance Field Using Static Mesh In C++

Do anyone know how can i write my own custom distance field data to static mesh.
I find the variable storing the data but if i write into it,it just crash the engine.
so do anyone has a safe way to write custom distance field for static mesh ???

p.s. : the path i write to is (UStaticMesh -> RenderData.Get() -> LODResources[0] -> DistanceFieldData) it is null so i try to create a new data for it but fail