Function offset_solid 

pub fn offset_solid(
    solid: &Polyhedron,
    distance: f64,
    direction: OffsetDirection,
) -> GeomResult<Polyhedron>

Offset a planar-faced solid by a constant distance.

Every vertex moves to the intersection of its own incident face planes, each pushed by distance. Topology is preserved, so the result has the same faces as the input with new coordinates.

Errors

Refuses a non-positive or non-finite distance, a vertex whose incident planes do not meet in a single point, and any inward offset that collapses the solid.