Add API for list of vehicle names

AirLib/include/api/RpcLibClientBase.hpp

@@ -129,6 +129,7 @@ namespace airlib
         bool isRecording();
 
         void simSetWind(const Vector3r& wind) const;
+        vector<string> listVehicles();
 
         std::string getSettingsString() const;
 

AirLib/include/api/WorldSimApiBase.hpp

@@ -82,6 +82,7 @@ namespace airlib
         virtual bool isRecording() const = 0;
 
         virtual void setWind(const Vector3r& wind) const = 0;
+        virtual vector<string> listVehicles() const = 0;
 
         virtual std::string getSettingsString() const = 0;
     };

AirLib/include/common/common_utils/UniqueValueMap.hpp

@@ -73,11 +73,20 @@ class UniqueValueMap
         return vals_.size();
     }
 
+    std::vector<TKey> keys() const
+    {
+        std::vector<TKey> ret;
+        for (const auto& element : map_) {
+            ret.push_back(element.first);
+        }
+        return ret;
+    }
+
     //TODO: add erase methods
 
 private:
     std::map<TKey, TVal> map_;
     std::set<TVal> vals_;
 };
 }
-#endif
+#endif

AirLib/src/api/RpcLibClientBase.cpp

@@ -483,6 +483,11 @@ __pragma(warning(disable : 4239))
             pimpl_->client.call("simSetWind", conv_wind);
         }
 
+        vector<string> RpcLibClientBase::listVehicles()
+        {
+            return pimpl_->client.call("listVehicles").as<vector<string>>();
+        }
+
         std::string RpcLibClientBase::getSettingsString() const
         {
             return pimpl_->client.call("getSettingsString").as<std::string>();

AirLib/src/api/RpcLibServerBase.cpp

@@ -383,6 +383,10 @@ namespace airlib
             getWorldSimApi()->setWind(wind.to());
         });
 
+        pimpl_->server.bind("listVehicles", [&]() -> vector<string> {
+            return getWorldSimApi()->listVehicles();
+        });
+
         pimpl_->server.bind("getSettingsString", [&]() -> std::string {
             return getWorldSimApi()->getSettingsString();
         });

PythonClient/airsim/client.py

@@ -851,13 +851,22 @@ def simAddVehicle(self, vehicle_name, vehicle_type, pose, pawn_path = ""):
             vehicle_name (str): Name of the vehicle being created
             vehicle_type (str): Type of vehicle, e.g. "simpleflight"
             pose (Pose): Initial pose of the vehicle
-            pawn_path (str): Vehicle blueprint path, default empty wbich uses the default blueprint for the vehicle type
+            pawn_path (str, optional): Vehicle blueprint path, default empty wbich uses the default blueprint for the vehicle type
 
         Returns:
             bool: Whether vehicle was created
         """
         return self.client.call('simAddVehicle', vehicle_name, vehicle_type, pose, pawn_path)
 
+    def listVehicles(self):
+        """
+        Lists the names of current vehicles
+
+        Returns:
+            list[str]: List containing names of all vehicles
+        """
+        return self.client.call('listVehicles')
+
     def getSettingsString(self):
         """
         Fetch the settings text being used by AirSim

Unity/AirLibWrapper/AirsimWrapper/Source/WorldSimApi.cpp

@@ -218,7 +218,17 @@ bool WorldSimApi::isRecording() const
 void WorldSimApi::setWind(const Vector3r& wind) const
 {
     simmode_->setWind(wind);
-};
+}
+
+std::vector<std::string> WorldSimApi::listVehicles() const
+{
+    auto vehicle_names = (simmode_->getApiProvider()->getVehicleSimApis()).keys();
+    // Remove '' from the list, representing default vehicle
+    auto position = std::find(vehicle_names.begin(), vehicle_names.end(), "");
+    if (position != vehicle_names.end())
+        vehicle_names.erase(position);
+    return vehicle_names;
+}
 
 bool WorldSimApi::addVehicle(const std::string& vehicle_name, const std::string& vehicle_type, const WorldSimApi::Pose& pose, const std::string& pawn_path)
 {

Unity/AirLibWrapper/AirsimWrapper/Source/WorldSimApi.h

@@ -65,6 +65,7 @@ class WorldSimApi : public msr::airlib::WorldSimApiBase
     virtual void setWind(const Vector3r& wind) const override;
     virtual bool createVoxelGrid(const Vector3r& position, const int& x_size, const int& y_size, const int& z_size, const float& res, const std::string& output_file) override;
     virtual bool addVehicle(const std::string& vehicle_name, const std::string& vehicle_type, const Pose& pose, const std::string& pawn_path = "") override;
+    virtual std::vector<std::string> listVehicles() const override;
 
     virtual std::string getSettingsString() const override;
 

Unreal/Plugins/AirSim/Source/WorldSimApi.cpp

@@ -607,6 +607,22 @@ void WorldSimApi::setWind(const Vector3r& wind) const
     simmode_->setWind(wind);
 }
 
+std::vector<std::string> WorldSimApi::listVehicles() const
+{
+    std::vector<std::string> vehicle_names;
+
+    UAirBlueprintLib::RunCommandOnGameThread([this, &vehicle_names]() {
+        vehicle_names = (simmode_->getApiProvider()->getVehicleSimApis()).keys();
+    },
+                                             true);
+
+    // Remove '' from the list, representing default vehicle
+    auto position = std::find(vehicle_names.begin(), vehicle_names.end(), "");
+    if (position != vehicle_names.end())
+        vehicle_names.erase(position);
+    return vehicle_names;
+}
+
 std::string WorldSimApi::getSettingsString() const
 {
     return msr::airlib::AirSimSettings::singleton().settings_text_;

Unreal/Plugins/AirSim/Source/WorldSimApi.h

@@ -70,6 +70,7 @@ class WorldSimApi : public msr::airlib::WorldSimApiBase
 
     virtual void setWind(const Vector3r& wind) const override;
     virtual bool createVoxelGrid(const Vector3r& position, const int& x_size, const int& y_size, const int& z_size, const float& res, const std::string& output_file) override;
+    virtual std::vector<std::string> listVehicles() const override;
 
     virtual std::string getSettingsString() const override;
 

docs/multi_vehicle.md

@@ -53,5 +53,12 @@ The new APIs since AirSim 1.2 allows you to specify `vehicle_name`. This name co
 
 [Example code for multirotors](https://github.com/Microsoft/AirSim/tree/master/PythonClient//multirotor/multi_agent_drone.py)
 
+Using APIs for multi-vehicles requires specifying the `vehicle_name`, which needs to be hardcoded in the script or requires parsing of the settings file. There's also a simple API `listVehicles()` which returns a list (vector in C++) of strings containing names of the current vehicles. For example, with the above settings for 2 Cars -
+
+```
+>>> client.listVehicles()
+['Car1', 'Car2']
+```
+
 ### Demo
 [![AirSimMultiple Vehicles Demo Video](images/demo_multi_vehicles.png)](https://youtu.be/35dgcuLuF5M)