Add array spawn service.

CMakeLists.txt

@@ -33,6 +33,7 @@ set(msg_files
 )
 
 set(srv_files
+    "srv/BatchSpawnEntities.srv"
     "srv/DeleteEntity.srv"
     "srv/GetAvailableWorlds.srv"
     "srv/GetCurrentWorld.srv"

msg/SimulatorFeatures.msg

@@ -38,6 +38,8 @@ uint8 WORLD_UNLOADING           = 43      # Supports UnloadWorld interface
 uint8 WORLD_INFO_GETTING        = 44      # Supports GetCurrentWorld interface
 uint8 AVAILABLE_WORLDS          = 45      # Supports GetAvailableWorlds interface
 
+uint8 SPAWNING_BATCH            = 50      # Support batch spawning (SpawnEntities)
+
 uint16[] features                         # A list of simulation features as specified by the list above.
 
 # A list of additional supported formats for spawning, which might be empty. Values may include

srv/BatchSpawnEntities.srv

@@ -0,0 +1,42 @@
+# Spawn entities (a robot, other object) by name or URI in a batch.
+# Support for this interface is indicated through the SPAWNING_BATCH value in GetSimulationFeatures.
+
+string names[]                          # A list of names given to every entity
+                                        # If string is empty, a name field in the uri file or resource_string will be used,
+                                        # if supported and not empty (e.g. "name" field in SDFormat, URDF).
+                                        # If the name is still empty or not unique (as determined by the simulator),
+                                        # the service returns a generated name in the entity_name response field if the
+                                        # allow_renaming field is set to true. Otherwise, the service call fails and an
+                                        # error is returned. 
+bool allow_renaming[]                   # Determines whether the spawning succeeds with a non-unique name.
+                                        # If it is set to true, the user should always check entity_name response field
+                                        # and use it for any further interactions. Number of elements have to match Number
+                                        # of elements in names.
+
+Resource entity_resources[]             # List of resources such as SDFormat, URDF, USD or MJCF file, a native prefab, etc.
+                                        # Valid URIs can be determined by calling GetSpawnables first. 
+                                        # Check simulator format support via the spawn_formats field in GetSimulatorFeatures.
+                                        # Using resource_string is supported if GetSimulatorFeatures includes
+                                        # the SPAWNING_RESOURCE_STRING feature. Number of elements have to match Number
+                                        # of elements in names.
+
+string entity_namespaces[]              # Spawn entities with theirs interfaces under those namespaces. Number of elements have to match Number
+                                        # of elements in names.
+geometry_msgs/PoseStamped initial_poses[] # Array of initial poses for every enttiy.
+                                        # The header contains a reference frame, which defaults to global "world" frame.
+                                        # This frame must be known to the simulator, e.g. of an object spawned earlier.
+                                        # The timestamp field in the header is ignored. Number of elements have to match Number
+                                        # of elements in names.
+
+---
+
+# Additional result.result_code values for this service. Check result.error_message for further details.
+
+uint8 BATCH_SPAWN_MISMATCH  = 110       # There is a mismatch in number of elements in names, allow_renaming, entity_resources, 
+                                        # entity_namespaces, initial_poses.
+uint8 BATCH_SPAWN_FAILED    = 120       # There was at least one failed spawn request. Check individual results in results.
+
+Result result                           # If all spawning request succeeded it will give RESULT_OK or BATCH_SPAWN_FAILED
+Result results[]                        # Individual spawn request results. Supported return codes are in SpanwEntity.srv.
+string entity_names[]                   # List of names of spawned entities, guaranteed to be unique in the simulation.
+                                        # If allow_renaming is true, it may differ from the request name field.