Function fillet_edge 

pub fn fillet_edge(
    model: &mut Model,
    solid: &Shape,
    edge: &Shape,
    radius: f64,
    tol: Tolerances,
) -> OgeomResult<Built>

Round a convex edge of a solid with a constant-radius blend tangent to both of its faces.

Two seats are recognised, and each has a closed-form envelope: a straight edge between two planar faces, where the rolling ball traces a cylinder, and a circular rim where a cylindrical wall meets a perpendicular planar cap, where it traces a torus. In both, the result is the boolean difference with a wedge whose curved face is that envelope, so the history reads as a cut: the faces are modified into their trimmed pieces, and the edge’s neighbourhood gains the blend face.

Errors

OgeomError::Construction if the edge is neither of the seats above, is concave, or radius is not a usable length.