public Volume3d createEnclosingVolume(Volume3d s1, Volume3d s2) {
   switch (chainTree.volumeMode) {
     case OBB:
       return Box3d.createBoundingBox_Covariance((Box3d) s1, (Box3d) s2);
     case CAPSULE:
       return Capsule3d.createBoundingCapsule_MaxDist((Capsule3d) s1, (Capsule3d) s2);
     case RSS:
       return RSS3d.createBoundingRSS_covariance((RSS3d) s1, (RSS3d) s2);
     case PSS:
       return Sphere3d.createBoundingSphere((Sphere3d) s1, (Sphere3d) s2);
   }
   throw new Error("Unknown volume type chosen: " + chainTree.volumeMode);
 }