Fix Recording when no vehicles are specified

Also change all occurrences of simmode strings to fixed variables

AirLib/include/common/AirSimSettings.hpp

@@ -35,6 +35,10 @@ struct AirSimSettings {
     static constexpr char const * kVehicleInertialFrame = "VehicleInertialFrame";
     static constexpr char const * kSensorLocalFrame = "SensorLocalFrame";
 
+    static constexpr char const * kSimModeTypeMultirotor = "Multirotor";
+    static constexpr char const * kSimModeTypeCar = "Car";
+    static constexpr char const * kSimModeTypeComputerVision = "ComputerVision";
+
     struct SubwindowSetting {
         int window_index;
         ImageType image_type;
@@ -521,7 +525,7 @@ struct AirSimSettings {
 
         physics_engine_name = settings_json.getString("PhysicsEngineName", "");
         if (physics_engine_name == "") {
-            if (simmode_name == "Multirotor")
+            if (simmode_name == kSimModeTypeMultirotor)
                 physics_engine_name = "FastPhysicsEngine";
             else
                 physics_engine_name = "PhysX"; //this value is only informational for now
@@ -538,9 +542,9 @@ struct AirSimSettings {
         std::string view_mode_string = settings_json.getString("ViewMode", "");
 
         if (view_mode_string == "") {
-            if (simmode_name == "Multirotor")
+            if (simmode_name == kSimModeTypeMultirotor)
                 view_mode_string = "FlyWithMe";
-            else if (simmode_name == "ComputerVision")
+            else if (simmode_name == kSimModeTypeComputerVision)
                 view_mode_string = "Fpv";
             else
                 view_mode_string = "SpringArmChase";
@@ -571,12 +575,24 @@ struct AirSimSettings {
         Settings rc_json;
         if (settings_json.getChild("RC", rc_json)) {
             rc_setting.remote_control_id = rc_json.getInt("RemoteControlID",
-                simmode_name == "Multirotor" ? 0 : -1);
+                simmode_name == kSimModeTypeMultirotor ? 0 : -1);
             rc_setting.allow_api_when_disconnected = rc_json.getBool("AllowAPIWhenDisconnected",
                 rc_setting.allow_api_when_disconnected);
         }
     }
 
+    // Get name of the default vehicle created for the specfifc simmode
+    // Based on initializeVehicleSettings() (#L803)
+    static std::string getDefaultVehicleName(const std::string& simmode_name)
+    {
+        if (simmode_name == kSimModeTypeMultirotor)
+            return "SimpleFlight";
+        else if (simmode_name == kSimModeTypeCar)
+            return "PhysXCar";
+        else
+            return "ComputerVision";
+    }
+
     static std::string getCameraName(const Settings& settings_json)
     {
         return settings_json.getString("CameraName",
@@ -611,13 +627,15 @@ struct AirSimSettings {
 
                 for (size_t child_index = 0; child_index < req_cameras_settings.size(); ++child_index) {
                     Settings req_camera_settings;
+                    std::string default_vehicle_name = getDefaultVehicleName(simmode_name);
+
                     if (req_cameras_settings.getChild(child_index, req_camera_settings)) {
                         std::string camera_name = getCameraName(req_camera_settings);
                         ImageType image_type = Utils::toEnum<ImageType>(
                                                 req_camera_settings.getInt("ImageType", 0));
                         bool compress = req_camera_settings.getBool("Compress", true);
                         bool pixels_as_float = req_camera_settings.getBool("PixelsAsFloat", false);
-                        std::string vehicle_name = req_camera_settings.getString("VehicleName", "");
+                        std::string vehicle_name = req_camera_settings.getString("VehicleName", default_vehicle_name);
 
                         recording_setting.requests[vehicle_name].push_back(ImageCaptureBase::ImageRequest(
                             camera_name, image_type, pixels_as_float, compress));
@@ -1105,7 +1123,7 @@ struct AirSimSettings {
         }
 
         if (std::isnan(camera_director.follow_distance)) {
-            if (simmode_name == "Car")
+            if (simmode_name == kSimModeTypeCar)
                 camera_director.follow_distance = -8;
             else
                 camera_director.follow_distance = -3;
@@ -1115,7 +1133,7 @@ struct AirSimSettings {
         if (std::isnan(camera_director.position.y()))
             camera_director.position.y() = 0;
         if (std::isnan(camera_director.position.z())) {
-            if (simmode_name == "Car")
+            if (simmode_name == kSimModeTypeCar)
                 camera_director.position.z() = -4;
             else
                 camera_director.position.z() = -2;
@@ -1131,7 +1149,7 @@ struct AirSimSettings {
             clock_type = "ScalableClock";
 
             //override if multirotor simmode with simple_flight
-            if (simmode_name == "Multirotor") {
+            if (simmode_name == kSimModeTypeMultirotor) {
                 //TODO: this won't work if simple_flight and PX4 is combined together!
 
                 //for multirotors we select steppable fixed interval clock unless we have
@@ -1301,13 +1319,13 @@ struct AirSimSettings {
     static void createDefaultSensorSettings(const std::string& simmode_name,
         std::map<std::string, std::unique_ptr<SensorSetting>>& sensors)
     {
-        if (simmode_name == "Multirotor") {
+        if (simmode_name == kSimModeTypeMultirotor) {
             sensors["imu"] = createSensorSetting(SensorBase::SensorType::Imu, "imu", true);
             sensors["magnetometer"] = createSensorSetting(SensorBase::SensorType::Magnetometer, "magnetometer", true);
             sensors["gps"] = createSensorSetting(SensorBase::SensorType::Gps, "gps", true);
             sensors["barometer"] = createSensorSetting(SensorBase::SensorType::Barometer, "barometer", true);
         }
-        else if (simmode_name == "Car") {
+        else if (simmode_name == kSimModeTypeCar) {
             sensors["gps"] = createSensorSetting(SensorBase::SensorType::Gps, "gps", true);
         }
         else {