Hi. I am looking to procedurally create morph targets for Unreal Engine 4 meshes from variations of a common base mesh.

There's a simple-enough struct that contains the per-vertex morphing info: http://api.unrealengine.com/INT/API/Runtime/Engine/Animation/FMorphTargetDelta/index.html

The problem is I don't know how to define a delta for a normal vector. I have both the unmorphed and the morphed normal, but what to do with them?

Oh wait... I think I get it now. I'm probably just supposed to subtract one from the other, just like with positions.

... right??

I would think so.  That's what 'delta' usually means in mathematics.