Fix compilation for tests; always create ConstraintSolver.contact_island

Author: gasnica

genesis/engine/solvers/rigid/constraint_solver_decomp.py

@@ -9,6 +9,7 @@
 import genesis.utils.geom as gu
 import genesis.utils.array_class as array_class
 import genesis.engine.solvers.rigid.rigid_solver_decomp as rigid_solver
+from genesis.engine.solvers.rigid.contact_island import ContactIsland
 
 if TYPE_CHECKING:
     from genesis.engine.solvers.rigid.rigid_solver_decomp import RigidSolver
@@ -160,6 +161,10 @@ def __init__(self, rigid_solver: "RigidSolver"):
 
         self.reset()
 
+        # Creating a dummy ContactIsland, needed as param for some functions,
+        # and not used when hibernation is not enabled.
+        self.contact_island = ContactIsland(self._collider)
+
     def clear(self, envs_idx: npt.NDArray[np.int32] | None = None):
         self._eq_const_info_cache.clear()
         if envs_idx is None:

genesis/engine/solvers/rigid/contact_island.py

@@ -32,26 +32,25 @@ def __init__(self, collider: "Collider"):
             start=gs.ti_int,
         )
 
-        self.ci_edges = ti.field(
-            dtype=gs.ti_int, shape=self.solver._batch_shape((self.collider._collider_info._max_contact_pairs[None], 2))
-        )
+        max_num_contact_pairs = self.collider._collider_info._max_contact_pairs[None]
+        max_num_contact_pairs = max(max_num_contact_pairs, 1)  # can't create 0-sized fields
+
+        self.ci_edges = ti.field(dtype=gs.ti_int, shape=self.solver._batch_shape((max_num_contact_pairs, 2)))
 
         # maps half-edges (half-edges are referenced by entity_edge range) to actual edge index
         # description: half_edge_ref_to_edge_idx
         self.edge_id = ti.field(
             dtype=gs.ti_int,
-            shape=self.solver._batch_shape((self.collider._collider_info._max_contact_pairs[None] * 2)),
+            shape=self.solver._batch_shape((max_num_contact_pairs * 2)),
         )
 
         # maps collider_state.contact_data index to island idx
-        self.constraint_list = ti.field(
-            dtype=gs.ti_int, shape=self.solver._batch_shape((self.collider._collider_info._max_contact_pairs[None]))
-        )
+        self.constraint_list = ti.field(dtype=gs.ti_int, shape=self.solver._batch_shape((max_num_contact_pairs)))
 
         # analogous to edge_id: maps island's constraint local-index to world's contact index
         self.constraint_id = ti.field(
             dtype=gs.ti_int,
-            shape=self.solver._batch_shape((self.collider._collider_info._max_contact_pairs[None] * 2)),
+            shape=self.solver._batch_shape((max_num_contact_pairs * 2)),
         )
 
         # per-entity range of half-edges (indexing into edge_id)

genesis/engine/solvers/rigid/rigid_solver_decomp.py

@@ -921,15 +921,6 @@ def _init_constraint_solver(self):
     def substep(self):
         # from genesis.utils.tools import create_timer
 
-        # Note: ContactIsland param is needed when supporting hibernation. But the attribute does not exist
-        # in the solver when hibernation is disabled. In that case, we create a dummy ContactIsland object
-        # needed for compilation, but not being used in the kernel.
-        if not hasattr(self, "optional_contact_island"):
-            if hasattr(self, "constraint_solver") and hasattr(self.constraint_solver, "contact_island"):
-                self.optional_contact_island = self.constraint_solver.contact_island
-            else:
-                self.optional_contact_island = ContactIsland(self.collider)
-
         # timer = create_timer("rigid", level=1, ti_sync=True, skip_first_call=True)
         kernel_step_1(
             links_state=self.links_state,
@@ -944,7 +935,7 @@ def substep(self):
             entities_info=self.entities_info,
             rigid_global_info=self._rigid_global_info,
             static_rigid_sim_config=self._static_rigid_sim_config,
-            contact_island=self.optional_contact_island,
+            contact_island=self.constraint_solver.contact_island,
         )
         # timer.stamp("kernel_step_1")
         self._func_constraint_force()
@@ -963,7 +954,7 @@ def substep(self):
             collider_state=self.collider._collider_state,
             rigid_global_info=self._rigid_global_info,
             static_rigid_sim_config=self._static_rigid_sim_config,
-            contact_island=self.optional_contact_island,
+            contact_island=self.constraint_solver.contact_island,
         )
         # timer.stamp("kernel_step_2")
 
@@ -1015,6 +1006,7 @@ def _func_forward_dynamics(self):
             geoms_state=self.geoms_state,
             rigid_global_info=self._rigid_global_info,
             static_rigid_sim_config=self._static_rigid_sim_config,
+            contact_island=self.constraint_solver.contact_island,
         )
 
     def _func_update_acc(self):
@@ -3023,6 +3015,7 @@ def kernel_forward_dynamics(
     geoms_state: array_class.GeomsState,
     rigid_global_info: array_class.RigidGlobalInfo,
     static_rigid_sim_config: ti.template(),
+    contact_island: ti.template(),  # ContactIsland
 ):
     func_forward_dynamics(
         links_state=links_state,
@@ -3035,6 +3028,7 @@ def kernel_forward_dynamics(
         geoms_state=geoms_state,
         rigid_global_info=rigid_global_info,
         static_rigid_sim_config=static_rigid_sim_config,
+        contact_island=contact_island,
     )