Fix wrong arrow circle orientation when specifying normal -Z

source/RobotAPI/components/ArViz/Client/Elements.cpp

@@ -107,9 +107,9 @@ namespace armarx::viz
         float angle = std::acos(naturalDir.dot(dir));
         if (cross.squaredNorm() < 1.0e-12f)
         {
-            // Directions are almost colinear ==> Do no rotation
+            // Directions are almost colinear ==> Angle is either 0 or 180 deg
             cross = Eigen::Vector3f::UnitX();
-            angle = 0.0f;
+            // Keep angle
         }
         Eigen::Vector3f axis = cross.normalized();
         Eigen::Quaternionf ori(Eigen::AngleAxisf(angle, axis));