Allow random routes to vary across traffic groups.

scenarios/sumo/intersections/4lane/scenario.py

@@ -74,18 +74,20 @@
     ),
 ]
 
+variations = 40
 scenario = Scenario(
     traffic={
-        "basic": Traffic(
+        f"t{i}": Traffic(
             flows=[
                 Flow(
                     route=RandomRoute(),
-                    repeat_route=True,
                     rate=3600,
+                    randomly_spaced=True,
                     actors={TrafficActor(name="car"): 1.0},
                 )
             ]
         )
+        for i in range(variations)
     },
     ego_missions=ego_missions,
     map_spec=MapSpec(

smarts/sstudio/genscenario.py

@@ -27,6 +27,7 @@
 import logging
 import os
 import pickle
+import random
 import sqlite3
 from dataclasses import dataclass, replace
 from pathlib import Path
@@ -35,6 +36,7 @@
 import cloudpickle
 import yaml
 
+import smarts.core
 from smarts.core.default_map_builder import find_mapfile_in_dir
 from smarts.core.utils.file import file_md5_hash, path2hash, pickle_hash
 from smarts.core.utils.logging import timeit
@@ -164,6 +166,7 @@ def gen_scenario(
     """
     # XXX: For now this simply coalesces the sub-calls but in the future this allows
     #      us to simplify our serialization between SStudio and SMARTS.
+    smarts.core.seed(seed)
 
     scenario_dir = os.path.abspath(str(output_dir))
     build_dir = os.path.join(scenario_dir, "build")
@@ -243,11 +246,12 @@ def gen_scenario(
     ):
         with timeit("traffic", logger.info):
             for name, traffic in scenario.traffic.items():
+                derived_seed = random.randint(-0b111111111111111, 0b111111111111111)
                 gen_traffic(
                     scenario=scenario_dir,
                     traffic=traffic,
                     name=name,
-                    seed=seed,
+                    seed=derived_seed,
                     map_spec=map_spec,
                 )
             _update_artifacts(db_conn, artifact_paths, obj_hash)