Vertex Interpolator doesn't work with landscape

I’m creating a retro game with affine texture mapping which (as far as I know) requires vertex interpolator to work. Is there any way to achieve the effect on a landscape? I’d prefer not to export landscape as an FBX and the use it as a static mesh.

Has this been solved?

Its kinda pointless.

Performance of landscape has gotten so much worse that all you can do is export it as an FBX and cut it up for usage…