The tyPush modifier is an alternative to 3ds Max’s built-in Push modifier, that allows you to specify a push direction, rather than simply pushing vertices along their normals.
Vertex normals: vertices will be pushed along the direction of their normals.
Local space vector: vertices will be pushed along the specified vector in local space.
World space vector: vertices will be pushed along the specified vector in world space.
Open edges outwards: vertices on open edges will be pushed outwards, perpendicular to the normals of their adjacent faces.
Amount: the amount to push vertices along the specified direction.
X/Y/Z: the user-defined push vector.