[Maya][ShaderFX] How to get screen space normals?

Hey all,

Does anyone know how to get screen space normals with ShaderFX in Maya 2019?

When I’ve tried doing matcap style shaders I’ve used the naive approach of multiplying my ws normals with the view matrix. This produces correct results when looking straight at the surface (center screen), but as object moves to sides of the screen the texture placement “floats” about the object. This is due to my logic not accounting for the perspective of the camera.

Any ideas?