skip rotation if particle is already at rest

corsika/detail/framework/geometry/CoordinateSystem.inl

@@ -81,7 +81,13 @@ namespace corsika {
   template <typename TDim>
   inline CoordinateSystemPtr make_rotationToZ(CoordinateSystemPtr const& cs,
                                               Vector<TDim> const& vVec) {
-    auto const a = vVec.normalized().getComponents(cs).getEigenVector();
+    auto const vVecComp = vVec.getComponents(cs);
+    if (vVecComp.getX().magnitude() == 0 && vVecComp.getY().magnitude() == 0 &&
+        vVecComp.getZ().magnitude() == 0) {
+      return cs;
+    }
+
+    auto const a = vVecComp.normalized().getEigenVector();
     auto const a1 = a(0), a2 = a(1), a3 = a(2);
 
     Eigen::Matrix3d A, B;

corsika/framework/utility/COMBoost.hpp

@@ -86,7 +86,7 @@ namespace corsika {
     //! internal method
     void setBoost(double const coshEta, double const sinhEta);
 
-  private:
+  public:
     Eigen::Matrix2d boost_;
     Eigen::Matrix2d inverseBoost_;
     CoordinateSystemPtr const originalCS_;