added minor visualization changes

src/msckf_vio.cpp

@@ -1836,12 +1836,22 @@ void MsckfVio::publish(const ros::Time& time) {
   Eigen::Vector3d body_velocity =
     IMUState::T_imu_body.linear() * imu_state.velocity;
 
+  // Generate camera frame form IMU Frame
+  Eigen::Isometry3d T_i_c = Eigen::Isometry3d::Identity();
+  T_i_c.linear() =  imu_state.R_imu_cam0;
+  T_i_c.translation() = imu_state.t_cam0_imu;
+
   // Publish tf
   if (publish_tf) {
     tf::Transform T_b_w_tf;
     tf::transformEigenToTF(T_b_w, T_b_w_tf);
     tf_pub.sendTransform(tf::StampedTransform(
           T_b_w_tf, time, fixed_frame_id, child_frame_id));
+
+    tf::Transform T_i_c_tf;
+    tf::transformEigenToTF(T_i_c, T_i_c_tf);
+    tf_pub.sendTransform(tf::StampedTransform(
+          T_i_c_tf, time, child_frame_id, "camera"));
   }
 
   // Publish the odometry