Resolve "Add time_tolerance field in Frame and remove PackKeyFrame"

Closes #420 (closed)

include/core/factor/factor_distance_3d.h

@@ -78,10 +78,6 @@ class FactorDistance3d : public FactorAutodiff<FactorDistance3d, 1, 3, 3>
                 norm_squared += (T)1e-8;
             }
             Matrix<T,1,1> dist_exp ( sqrt(norm_squared) );
-            // Matrix<T,1,1> dist_meas (getMeasurement().cast<T>());
-            // Matrix<T,1,1> sqrt_info_upper = getMeasurementSquareRootInformationUpper();
-
-            // res  = sqrt_info_upper * (dist_meas - dist_exp);
 
             res  = getMeasurementSquareRootInformationUpper() * (getMeasurement() - dist_exp);