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. With no excluded face the wall closes round a cavity, which only the exact path (thick_solid_by_image) builds.

Errors

Returns OffsetError if the offset collapses the solid, any intersection fails, the result cannot be assembled into a valid solid, or no face is excluded and the exact path does not apply.