Enable MuJoCo tendon parsing in Newton physics replication

Add SchemaResolverMjc to the schema resolver list and call
SolverMuJoCo.register_custom_attributes on the main ModelBuilder before
add_usd in newton_replicate.py. Both are required for MjcTendon prims
(fixed-tendon schema in USD) to be recognized and land in the MuJoCo
solver model. Without this, USD assets that carry tendon annotations
(e.g. MuJoCo Menagerie's Shadow Hand) were silently parsed without
tendons, causing the fixed-tendon finger coupling to be absent from the
Newton simulation.

Bumps isaaclab_newton to 0.5.15.

Author: Horde

source/isaaclab_newton/config/extension.toml

@@ -1,7 +1,7 @@
 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.5.14"
+version = "0.5.15"
 
 # Description
 title = "Newton simulation interfaces for IsaacLab core package"

source/isaaclab_newton/docs/CHANGELOG.rst

@@ -1,6 +1,21 @@
 Changelog
 ---------
 
+0.5.15 (2026-04-28)
+~~~~~~~~~~~~~~~~~~~
+
+Fixed
+^^^^^
+
+* Fixed Newton physics replication to enable MuJoCo tendon parsing from USD.
+  :func:`~isaaclab_newton.cloner.newton_replicate._build_newton_builder_from_mapping`
+  now includes :class:`SchemaResolverMjc` in its resolver list and calls
+  ``SolverMuJoCo.register_custom_attributes`` on the main builder, which are
+  both required for ``MjcTendon`` prims to land in the MuJoCo solver model.
+  Previously, USD assets with fixed-tendon schema (e.g. MuJoCo Menagerie's
+  Shadow Hand) were silently parsed without tendons.
+
+
 0.5.14 (2026-04-16)
 ~~~~~~~~~~~~~~~~~~~
 

source/isaaclab_newton/isaaclab_newton/cloner/newton_replicate.py

@@ -10,7 +10,7 @@
 import torch
 import warp as wp
 from newton import ModelBuilder, solvers
-from newton._src.usd.schemas import SchemaResolverNewton, SchemaResolverPhysx
+from newton._src.usd.schemas import SchemaResolverMjc, SchemaResolverNewton, SchemaResolverPhysx
 
 from pxr import Usd, UsdGeom
 
@@ -52,9 +52,12 @@ def _build_newton_builder_from_mapping(
         quaternions = torch.zeros((mapping.size(1), 4), device=mapping.device, dtype=torch.float32)
         quaternions[:, 3] = 1.0
 
-    schema_resolvers = [SchemaResolverNewton(), SchemaResolverPhysx()]
+    # SchemaResolverMjc parses MjcTendon prims (USD-tendon → MuJoCo solver fixed tendons).
+    schema_resolvers = [SchemaResolverMjc(), SchemaResolverNewton(), SchemaResolverPhysx()]
 
     builder = NewtonManager.create_builder(up_axis=up_axis)
+    # Required for SchemaResolverMjc to recognise MuJoCo-specific USD attributes.
+    solvers.SolverMuJoCo.register_custom_attributes(builder)
     stage_info = builder.add_usd(
         stage,
         ignore_paths=["/World/envs"] + sources,