Function thick_solid 

pub fn thick_solid(
    topo: &mut Topology,
    solid: SolidId,
    distance: f64,
    exclude: &[FaceId],
    options: OffsetOptions,
) -> Result<SolidId, OffsetError>

Offset a solid while excluding specific faces, producing a thick (hollowed) solid.

Excluded faces are left at their original positions, and side walls connect them to the offset faces.

Errors

Returns OffsetError if the offset collapses the solid, any intersection fails, or the result cannot be assembled into a valid solid.