add supoort for random init

Signed-off-by: zhx06 <zihaox@nvidia.com>

Author: zhx06

isaaclab_arena/assets/object.py

@@ -16,7 +16,12 @@
 from isaaclab_arena.utils.bounding_box import AxisAlignedBoundingBox, quaternion_to_90_deg_z_quarters
 from isaaclab_arena.utils.pose import Pose
 from isaaclab_arena.utils.usd.rigid_bodies import find_shallowest_rigid_body
-from isaaclab_arena.utils.usd_helpers import compute_local_bounding_box_from_usd, has_light, open_stage
+from isaaclab_arena.utils.usd_helpers import (
+    compute_local_bounding_box_from_usd,
+    extract_trimesh_from_usd,
+    has_light,
+    open_stage,
+)
 
 
 class Object(ObjectBase):
@@ -74,6 +79,31 @@ def get_bounding_box(self) -> AxisAlignedBoundingBox:
             self.bounding_box = compute_local_bounding_box_from_usd(self.usd_path, self.scale)
         return self.bounding_box
 
+    def get_collision_mesh(self):
+        """Lazily extract collision mesh from USD. Cached after first call."""
+        if not hasattr(self, "_collision_mesh"):
+            self._collision_mesh = None
+            if self.usd_path is not None:
+                try:
+                    self._collision_mesh = extract_trimesh_from_usd(self.usd_path, self.scale)
+                except (ValueError, RuntimeError, OSError) as e:
+                    print(f"  [MeshCollision] Could not extract mesh for '{self.name}': {e}")
+        return self._collision_mesh
+
+    def __deepcopy__(self, memo):
+        """Exclude _collision_mesh from deepcopy (trimesh has unpicklable C pointers)."""
+        import copy
+
+        cls = self.__class__
+        result = cls.__new__(cls)
+        memo[id(self)] = result
+        for k, v in self.__dict__.items():
+            if k == "_collision_mesh":
+                setattr(result, k, None)
+            else:
+                setattr(result, k, copy.deepcopy(v, memo))
+        return result
+
     def get_world_bounding_box(self) -> AxisAlignedBoundingBox:
         """Get bounding box in world coordinates (local bbox rotated and translated).
 

isaaclab_arena/cli/isaaclab_arena_cli.py

@@ -86,6 +86,13 @@ def add_isaaclab_arena_cli_args(parser: argparse.ArgumentParser) -> None:
             "Only affects objects positioned by the placement solver; manually-placed objects are unaffected."
         ),
     )
+    arena_group.add_argument(
+        "--collision_mode",
+        type=str,
+        choices=["bbox", "mesh"],
+        default="bbox",
+        help="Collision detection mode: 'bbox' (AABB, default) or 'mesh' (sphere-to-SDF, requires Warp).",
+    )
 
 
 def add_env_graph_spec_cli_args(parser: argparse.ArgumentParser) -> None:

isaaclab_arena/environments/arena_env_builder.py

@@ -73,6 +73,7 @@ def _solve_relations(self) -> None:
             placement_seed=self.args.placement_seed,
             resolve_on_reset=self.args.resolve_on_reset,
             random_yaw_init=self.args.random_yaw_init,
+            collision_mode=getattr(self.args, "collision_mode", "bbox"),
         )
 
     def get_all_variations(self) -> dict[str, list[VariationBase]]:

isaaclab_arena/environments/relation_solver_interface.py

@@ -26,6 +26,7 @@ def solve_and_apply_relation_placement(
     placement_seed: int | None = None,
     resolve_on_reset: bool | None = None,
     random_yaw_init: bool = False,
+    collision_mode: str = "bbox",
 ) -> EventTermCfg | None:
     """Solve relation placement and apply the result to object reset/static state.
 
@@ -38,20 +39,24 @@ def solve_and_apply_relation_placement(
             initial poses are applied immediately.
         random_yaw_init: If True, randomly rotates non-anchor objects around the vertical (Z)
             axis at startup to add visual variety to the scene.
+        collision_mode: Collision detection mode: "bbox" or "mesh".
 
     Returns:
         Reset event config to attach to the environment when placement should be
         resolved on reset. Returns ``None`` when no reset event is needed.
     """
+    from isaaclab_arena.relations.relation_solver_params import CollisionMode
+
     objects = list(objects)
     if not objects:
         print("No objects with relations found in scene. Skipping relation solving.")
         return None
 
+    mode = CollisionMode.MESH if collision_mode == "mesh" else CollisionMode.BBOX
     placer_params = ObjectPlacerParams(
         placement_seed=placement_seed,
         apply_positions_to_objects=False,
-        solver_params=RelationSolverParams(save_position_history=False, verbose=False),
+        solver_params=RelationSolverParams(collision_mode=mode, save_position_history=False, verbose=False),
         random_yaw_init=random_yaw_init,
     )
     if resolve_on_reset is not None: