Function sweep_solid_tumbled 

pub fn sweep_solid_tumbled(
    tool: &SolidTool,
    motion: &TwoTurns,
) -> Result<BrepSolid, KernelRefusal>

The whole sweep of a solid of revolution tumbled by two turns about skew axes. The grazing loop moves on the tool (the instantaneous screw changes with t), so the walls are lofted through exact samples. Where the tumble passes over a point twice (the one-pass probe), the time is bisected into spans each passing once, and the spans’ sweeps are joined (consecutive spans meet along a grazing loop; distant ones overlap).