MJX (impl='warp'): nconmax -> naconmax

PiperOrigin-RevId: 915407157
Change-Id: Ie43c06164d6d942c2a4bb60b3d09fcb5c4c87a35

doc/changelog.rst

@@ -59,6 +59,9 @@ General
      Negative ``margin`` values are now permitted (corresponding to ``gap > margin`` under the old semantics). The
      constraint ``margin + gap >= 0`` should be maintained to ensure valid collision detection.
 
+   - MJX: Removed the deprecated ``nconmax`` argument from ``mjx.make_data`` and ``mjx.put_data`` in favor of
+     ``naconmax``.
+
 Version 3.8.1 (May 11, 2026)
 ----------------------------
 

mjx/mujoco/mjx/_src/io.py

@@ -828,7 +828,6 @@ def make_data(
     device: Optional[jax.Device] = None,
     impl: Optional[Union[str, types.Impl]] = None,
     _full_compat: bool = False,  # pylint: disable=invalid-name
-    nconmax: Optional[int] = None,
     naconmax: Optional[int] = None,
     naccdmax: Optional[int] = None,
     njmax: Optional[int] = None,
@@ -840,15 +839,10 @@ def make_data(
     m: the model to use
     device: which device to use - if unspecified picks the default device
     impl: implementation to use ('jax', 'warp')
-    nconmax: maximum number of contacts to allocate for warp across all worlds
-      Since the number of worlds is **not** pre-defined in JAX, we use the
-      `nconmax` argument to set the upper bound for the number of contacts
-      across all worlds. In MuJoCo Warp, the analgous field is called
-      `naconmax`.
     naconmax: maximum number of contacts to allocate for warp across all worlds
       Since the number of worlds is **not** pre-defined in JAX, we use the
       `naconmax` argument to set the upper bound for the number of contacts
-      across all worlds, rather than the `nconmax` argument from MuJoCo Warp.
+      across all worlds.
     naccdmax: maximum number of contacts for GJK collision detection across all
       worlds. Since the number of worlds is **not** pre-defined in JAX, we use the
       `naccdmax` argument to set the upper bound for the number of contacts
@@ -864,14 +858,7 @@ def make_data(
   Raises:
     ValueError: if the model's impl does not match the make_data impl
     NotImplementedError: if the impl is not implemented yet
-    DeprecationWarning: if nconmax is used
   """
-  if nconmax is not None:
-    warnings.warn(
-        'nconmax will be deprecated in mujoco-mjx>=3.5. Use naconmax instead.',
-        DeprecationWarning,
-        stacklevel=2,
-    )
 
   impl, device = _resolve_impl_and_device(impl, device)
 
@@ -886,7 +873,6 @@ def make_data(
     return _make_data_cpp(m, device, keepalive_refs=keepalive_refs)
   elif impl == types.Impl.WARP:
     _check_warp_installed()
-    naconmax = nconmax if naconmax is None else naconmax
     return _make_data_warp(m, device, naconmax, naccdmax, njmax)
 
   raise NotImplementedError(
@@ -1187,7 +1173,6 @@ def put_data(
     d: mujoco.MjData,
     device: Optional[jax.Device] = None,
     impl: Optional[Union[str, types.Impl]] = None,
-    nconmax: Optional[int] = None,
     naconmax: Optional[int] = None,
     njmax: Optional[int] = None,
     dummy_arg_for_batching: Optional[jax.Array] = None,
@@ -1200,11 +1185,10 @@ def put_data(
     d: the data to put on device
     device: which device to use - if unspecified picks the default device
     impl: implementation to use ('jax', 'warp')
-    nconmax: maximum number of contacts to allocate for warp
     naconmax: maximum number of contacts to allocate for warp across all worlds
       Since the number of worlds is **not** pre-defined in JAX, we use the
       `naconmax` argument to set the upper bound for the number of contacts
-      across all worlds, rather than the `nconmax` argument from MuJoCo Warp.
+      across all worlds.
     njmax: maximum number of constraints to allocate for warp
     dummy_arg_for_batching: dummy argument to use for batching in cpp
       implementation
@@ -1213,14 +1197,7 @@ def put_data(
 
   Returns:
     an mjx.Data placed on device
-    DeprecationWarning: if nconmax is used
   """
-  if nconmax is not None:
-    warnings.warn(
-        'nconmax will be deprecated in mujoco-mjx>=3.5. Use naconmax instead.',
-        DeprecationWarning,
-        stacklevel=2,
-    )
 
   impl, device = _resolve_impl_and_device(impl, device)
   if impl == types.Impl.JAX:
@@ -1235,7 +1212,6 @@ def put_data(
     )
   elif impl == types.Impl.WARP:
     _check_warp_installed()
-    naconmax = nconmax if naconmax is None else naconmax
     return _put_data_warp(m, d, device, naconmax, njmax)
 
   raise NotImplementedError(

mjx/mujoco/mjx/_src/io_test.py

@@ -475,7 +475,7 @@ class DataIOTest(parameterized.TestCase):
     if not mjx_io.has_cuda_gpu_device():
       self.skipTest('No CUDA GPU device.')
     m = mujoco.MjModel.from_xml_string(_MULTIPLE_CONVEX_OBJECTS)
-    d = mjx.make_data(m, impl='warp', nconmax=9, njmax=23)
+    d = mjx.make_data(m, impl='warp', naconmax=9, njmax=23)
     self.assertEqual(d._impl.contact__dist.shape[0], 9)
     self.assertEqual(d._impl.efc__pos.shape[0], 23)
 

mjx/mujoco/mjx/warp/ffi.py

@@ -329,7 +329,7 @@ def _check_leading_dim(
     path: jax.tree_util.KeyPath,
     leaf: Any,
     expected_batch_dim: int,
-    expected_nconmax: int,
+    expected_naconmax: int,
     expected_njmax: int,
 ):
   """Asserts that the batch dimension of a leaf node matches the expected batch dimension."""
@@ -345,11 +345,11 @@ def _check_leading_dim(
   if (
       not has_batch_dim
       and attr.startswith('contact__')
-      and leaf.shape[0] != expected_nconmax
+      and leaf.shape[0] != expected_naconmax
   ):
     raise ValueError(
-        f'Leaf node leading dim ({leaf.shape[0]}) does not match nconmax'
-        f' ({expected_nconmax}) for field {attr}.'
+        f'Leaf node leading dim ({leaf.shape[0]}) does not match naconmax'
+        f' ({expected_naconmax}) for field {attr}.'
     )
   if (
       not has_batch_dim

mjx/mujoco/mjx/warp/test_util.py

@@ -41,10 +41,10 @@ def assert_attr_eq(a, b, attr):
 
 
 def make_data(
-    m: mujoco.MjModel, worldid: int, nconmax: int = 1_000, njmax: int = 200
+    m: mujoco.MjModel, worldid: int, naconmax: int = 1_000, njmax: int = 200
 ):
   """Make data for a given worldid using keyframes when available."""
-  dx = mjx.make_data(m, impl='warp', nconmax=nconmax, njmax=njmax)
+  dx = mjx.make_data(m, impl='warp', naconmax=naconmax, njmax=njmax)
 
   rng = jax.random.PRNGKey(worldid)
   rng, key = jax.random.split(rng)