Function project_point_to_surface 

pub fn project_point_to_surface(
    surface: &NurbsSurface,
    point: Vec3,
) -> Result<SurfaceProjection, String>

The point of surface nearest point, over the surface’s whole domain.

Analytic carriers answer in closed form; every other surface goes through project_point_to_surface_general, which says what it guarantees. #[track_caller] names the call site in the BREP_PROJECTION_AUDIT log.