Interpretation of Texture Sample by World Position Offset?

When I create a Mesh and Texture in an external app (Rhinoceros) which i want to use to drive World Position Offset in Unreal. Direction and positions of the Offset seems to be right but the proportion between the vectors seems to be wrong. While the proportion in Rhino is 1:2 which I correspondly colour coded in Unreal doesn’t seem to linearly interpolate here. (See Picture below).Can somebody tell how is that?