Function offset_revolution_face 

pub fn offset_revolution_face(
    solid: &BrepSolid,
    face_id: u64,
    distance: f64,
) -> Result<BrepSolid, String>

Push a general surface of revolution with planar neighbours.

The meridian is densely offset and interpolated, then revolved through the original full or partial sweep. A dense normal-distance residual check bounds that approximation. Endpoint rims and start/end meridians are rebuilt, and planar axial/radial neighbours are re-trimmed around the new boundary.

A boundary whose pcurve is NEITHER a constant-u nor a constant-v line is no longer refused outright: its 3D image on the offset carrier comes from crate::image_curve. That transfer is only valid where the boundary is definitional, so a general image against a FIXED planar cap is measured against that cap’s plane and refused — with the number — when it leaves it, because the honest answer there is a re-intersection this site does not do.