Description:
// The m_bCapped applies to planar, cylinder and box mappings. If m_bCapped is false, the cylinder or box is "infinite", if m_bCapped is true, they are finite. In planar mappings, m_bCapped=False means "the Z texture coordinate will always be 0.0" this is now the default behaviour in Rhino 5.0 - it's what users expect apparently.