Pad AABB to detect axis aligned collision (#1889)

* Pad AABB

* Bump up from ground.

CHANGELOG.md

@@ -17,6 +17,8 @@ Copy and pasting the git commit messages is __NOT__ enough.
 - Missing neighborhood vehicle ids are now added to the `highway-v1` formatted observations.
 - Stopped agent providers from removing social agents when they have no actor.
 - Using `trip` in sstudio traffic generation no longer causes a durouter error.
+- Chassis collision AABB first pass now has an additional `0.05m` tolerance to identify axis aligned collisions that would previously be missed.
+- Agent to mission padding warning now occurs when there are less missions than agents rather than when there are the same number of agents as missions.
 ### Removed
 ### Security
 

smarts/core/chassis.py

@@ -59,22 +59,27 @@
 
 def _query_bullet_contact_points(bullet_client, bullet_id, link_index):
     contact_objects = set()
+    # Give 0.05 meter leeway
+    LEEWAY = 0.05
 
     # `getContactPoints` does not pick up collisions well so we cast a fast box check on the physics
     min_, max_ = bullet_client.getAABB(bullet_id, link_index)
     # note that getAABB returns a box around the link_index link only,
     # which means it's offset from the ground (min_ has a positive z)
     # if link_index=0 (the chassis link) is used.
-    overlapping_objects = bullet_client.getOverlappingObjects(min_, max_)
+    overlapping_objects = bullet_client.getOverlappingObjects(
+        tuple(map(sum, zip(min_, (-LEEWAY, -LEEWAY, 0)))),
+        tuple(map(sum, zip(max_, (LEEWAY, LEEWAY, LEEWAY)))),
+    )
     # the pairs returned by getOverlappingObjects() appear to be in the form (body_id, link_idx)
     if overlapping_objects is not None:
         contact_objects = set(oo for oo, _ in overlapping_objects if oo != bullet_id)
 
     contact_points = []
     for contact_object in contact_objects:
-        # Give 0.05 meter leeway
+
         contact_points.extend(
-            bullet_client.getClosestPoints(bullet_id, contact_object, distance=0.05)
+            bullet_client.getClosestPoints(bullet_id, contact_object, distance=LEEWAY)
         )
 
     return contact_points

smarts/core/scenario.py

@@ -233,7 +233,7 @@ def variations_for_all_scenario_roots(
             # `or [None]` so that product(...) will not return an empty result
             # but insted a [(..., `None`), ...].
             agent_missions = agent_missions or [None]
-            if len(agents_to_be_briefed) == len(agent_missions):
+            if len(agents_to_be_briefed) > len(agent_missions):
                 warnings.warn(
                     f"Scenario `{scenario_root}` has {len(agent_missions)} missions and"
                     f" but there are {len(agents_to_be_briefed)} agents to assign"