Squashed commit of the following:

commit 7bab8a0
Author: Octi Zhang <zhengyuz@nvidia.com>
Date:   Thu Apr 9 18:11:47 2026 -0700

    line break

commit c9c1a29
Author: Octi Zhang <zhengyuz@nvidia.com>
Date:   Thu Apr 9 18:09:32 2026 -0700

    Add collision pipeline cfg, bump to 0.5.11

    Add NewtonCollisionPipelineCfg and HydroelasticSDFCfg to expose
    Newton's collision pipeline parameters (broad phase, contact limits,
    hydroelastic mode) through NewtonCfg.collision_cfg.

    Add MJWarpSolverCfg.tolerance for solver convergence control.

    Fix validation order so collision_cfg is stored before the
    use_mujoco_contacts consistency check runs.  Reset _collision_cfg
    in clear() to avoid stale state across reset cycles.  Fall back to
    a default CollisionPipeline when collision_cfg is None.

commit 43ae9f3
Author: Octi Zhang <zhengyuz@nvidia.com>
Date:   Thu Apr 9 18:06:21 2026 -0700

    expose newton collision cfg

Author: ooctipus

source/isaaclab_newton/config/extension.toml

@@ -1,7 +1,7 @@
 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.5.10"
+version = "0.5.11"
 
 # Description
 title = "Newton simulation interfaces for IsaacLab core package"

source/isaaclab_newton/docs/CHANGELOG.rst

@@ -1,6 +1,7 @@
 Changelog
 ---------
 
+
 0.5.13 (2026-04-09)
 ~~~~~~~~~~~~~~~~~~~
 
@@ -11,8 +12,17 @@ Added
   backend implementation for xform prim views.
 
 
-0.5.11 (2026-04-09)
+0.5.12 (2026-04-09)
+~~~~~~~~~~~~~~~~~~~
+Added
+^^^^^
 
+* Added :class:`~isaaclab_newton.physics.NewtonCollisionPipelineCfg` to expose Newton collision pipeline parameters via
+  :attr:`~isaaclab_newton.physics.NewtonCfg.collision_cfg`.
+
+
+0.5.11 (2026-04-09)
+~~~~~~~~~~~~~~~~~~~
 Added
 ^^^^^
 

source/isaaclab_newton/isaaclab_newton/physics/__init__.pyi

@@ -5,12 +5,21 @@
 
 __all__ = [
     "FeatherstoneSolverCfg",
+    "HydroelasticSDFCfg",
     "MJWarpSolverCfg",
     "NewtonCfg",
+    "NewtonCollisionPipelineCfg",
     "NewtonManager",
     "NewtonSolverCfg",
     "XPBDSolverCfg",
 ]
 
+from .newton_collision_cfg import HydroelasticSDFCfg, NewtonCollisionPipelineCfg
 from .newton_manager import NewtonManager
-from .newton_manager_cfg import FeatherstoneSolverCfg, MJWarpSolverCfg, NewtonCfg, NewtonSolverCfg, XPBDSolverCfg
+from .newton_manager_cfg import (
+    FeatherstoneSolverCfg,
+    MJWarpSolverCfg,
+    NewtonCfg,
+    NewtonSolverCfg,
+    XPBDSolverCfg,
+)

source/isaaclab_newton/isaaclab_newton/physics/newton_collision_cfg.py

@@ -0,0 +1,168 @@
+# Copyright (c) 2022-2026, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+"""Configuration for Newton collision pipeline."""
+
+from __future__ import annotations
+
+from typing import Literal
+
+from isaaclab.utils import configclass
+
+
+@configclass
+class HydroelasticSDFCfg:
+    """Configuration for SDF-based hydroelastic collision handling.
+
+    Hydroelastic contacts generate distributed contact areas instead of point contacts,
+    providing more realistic force distribution for manipulation and compliant surfaces.
+
+    For more details, see the `Newton Collisions Guide`_.
+
+    .. _Newton Collisions Guide: https://newton-physics.github.io/newton/latest/concepts/collisions.html#hydroelastic-contacts
+    """
+
+    reduce_contacts: bool = True
+    """Whether to reduce contacts to a smaller representative set per shape pair.
+
+    When False, all generated contacts are passed through without reduction.
+
+    Defaults to ``True`` (same as Newton's default).
+    """
+
+    buffer_fraction: float = 1.0
+    """Fraction of worst-case hydroelastic buffer allocations. Range: (0, 1].
+
+    Lower values reduce memory usage but may cause overflows in dense scenes.
+    Overflows are bounds-safe and emit warnings; increase this value when warnings appear.
+
+    Defaults to ``1.0`` (same as Newton's default).
+    """
+
+    normal_matching: bool = True
+    """Whether to rotate reduced contact normals to align with aggregate force direction.
+
+    Only active when ``reduce_contacts`` is True.
+
+    Defaults to ``True`` (same as Newton's default).
+    """
+
+    anchor_contact: bool = False
+    """Whether to add an anchor contact at the center of pressure for each normal bin.
+
+    The anchor contact helps preserve moment balance. Only active when ``reduce_contacts`` is True.
+
+    Defaults to ``False`` (same as Newton's default).
+    """
+
+    margin_contact_area: float = 0.01
+    """Contact area [m^2] used for non-penetrating contacts at the margin.
+
+    Defaults to ``0.01`` (same as Newton's default).
+    """
+
+    output_contact_surface: bool = False
+    """Whether to output hydroelastic contact surface vertices for visualization.
+
+    Defaults to ``False`` (same as Newton's default).
+    """
+
+
+@configclass
+class NewtonCollisionPipelineCfg:
+    """Configuration for Newton collision pipeline.
+
+    Full-featured collision pipeline with GJK/MPR narrow phase and pluggable broad phase.
+    When this config is set on :attr:`NewtonCfg.collision_cfg`:
+
+    - **MJWarpSolverCfg**: Newton's collision pipeline replaces MuJoCo's internal contact solver.
+    - **Other solvers** (XPBD, Featherstone, etc.): Configures the collision pipeline parameters
+      (these solvers always use Newton's collision pipeline).
+
+    Key features:
+
+    - GJK/MPR algorithms for convex-convex collision detection
+    - Multiple broad phase options: NXN (all-pairs), SAP (sweep-and-prune), EXPLICIT (precomputed pairs)
+    - Mesh-mesh collision via SDF with contact reduction
+    - Optional hydroelastic contact model for compliant surfaces
+
+    For more details, see the `Newton Collisions Guide`_ and `CollisionPipeline API`_.
+
+    .. _Newton Collisions Guide: https://newton-physics.github.io/newton/latest/concepts/collisions.html
+    .. _CollisionPipeline API: https://newton-physics.github.io/newton/api/_generated/newton.CollisionPipeline.html
+    """
+
+    broad_phase: Literal["explicit", "nxn", "sap"] = "explicit"
+    """Broad phase algorithm for collision detection.
+
+    Options:
+
+    - ``"explicit"``: Use precomputed shape pairs from ``model.shape_contact_pairs``.
+    - ``"nxn"``: All-pairs brute force. Simple but O(n^2) complexity.
+    - ``"sap"``: Sweep-and-prune. Good for scenes with many dynamic objects.
+
+    Defaults to ``"explicit"`` (same as Newton's default when ``broad_phase=None``).
+    """
+
+    reduce_contacts: bool = True
+    """Whether to reduce contacts for mesh-mesh collisions.
+
+    When True, uses shared memory contact reduction to select representative contacts.
+    Improves performance and stability for meshes with many vertices.
+
+    Defaults to ``True`` (same as Newton's default).
+    """
+
+    rigid_contact_max: int | None = None
+    """Maximum number of rigid contacts to allocate.
+
+    Resolution order:
+
+    1. If provided, use this value.
+    2. Else if ``model.rigid_contact_max > 0``, use the model value.
+    3. Else estimate automatically from model shape and pair metadata.
+
+    Defaults to ``None`` (auto-estimate, same as Newton's default).
+    """
+
+    max_triangle_pairs: int = 1_000_000
+    """Maximum number of triangle pairs allocated by narrow phase for mesh and heightfield collisions.
+
+    Increase this when scenes with large/complex meshes or heightfields report
+    triangle-pair overflow warnings.
+
+    Defaults to ``1_000_000`` (same as Newton's default).
+    """
+
+    soft_contact_max: int | None = None
+    """Maximum number of soft contacts to allocate.
+
+    If None, computed as ``shape_count * particle_count``.
+
+    Defaults to ``None`` (auto-compute, same as Newton's default).
+    """
+
+    soft_contact_margin: float = 0.01
+    """Margin [m] for soft contact generation.
+
+    Defaults to ``0.01`` (same as Newton's default).
+    """
+
+    requires_grad: bool | None = None
+    """Whether to enable gradient computation for collision.
+
+    If ``None``, uses ``model.requires_grad``.
+
+    Defaults to ``None`` (same as Newton's default).
+    """
+
+    sdf_hydroelastic_config: HydroelasticSDFCfg | None = None
+    """Configuration for SDF-based hydroelastic collision handling.
+
+    If ``None``, hydroelastic contacts are disabled.
+    If set, enables hydroelastic contacts with the specified parameters.
+
+    Defaults to ``None`` (hydroelastic disabled, same as Newton's default).
+    """

source/isaaclab_newton/isaaclab_newton/physics/newton_manager.py

@@ -28,6 +28,7 @@
         _cudart = None
 from newton import Axis, CollisionPipeline, Contacts, Control, Model, ModelBuilder, State, eval_fk
 from newton._src.usd.schemas import SchemaResolverNewton, SchemaResolverPhysx
+from newton.geometry import HydroelasticSDF
 from newton.sensors import SensorContact as NewtonContactSensor
 from newton.solvers import SolverBase, SolverFeatherstone, SolverMuJoCo, SolverNotifyFlags, SolverXPBD
 
@@ -38,6 +39,8 @@
 if TYPE_CHECKING:
     from isaaclab.sim.simulation_context import SimulationContext
 
+    from .newton_collision_cfg import NewtonCollisionPipelineCfg
+
 logger = logging.getLogger(__name__)
 
 
@@ -91,6 +94,7 @@ class NewtonManager(PhysicsManager):
     _contacts: Contacts | None = None
     _needs_collision_pipeline: bool = False
     _collision_pipeline = None
+    _collision_cfg: NewtonCollisionPipelineCfg | None = None
     _newton_contact_sensors: dict = {}  # Maps sensor_key to NewtonContactSensor
     _report_contacts: bool = False
     _fk_dirty: bool = False
@@ -365,6 +369,7 @@ def clear(cls):
         cls._contacts = None
         cls._needs_collision_pipeline = False
         cls._collision_pipeline = None
+        cls._collision_cfg = None
         cls._newton_contact_sensors = {}
         cls._report_contacts = False
         cls._fk_dirty = False
@@ -532,7 +537,15 @@ def _initialize_contacts(cls) -> None:
         if cls._needs_collision_pipeline:
             # Newton collision pipeline: create pipeline and generate contacts
             if cls._collision_pipeline is None:
-                cls._collision_pipeline = CollisionPipeline(cls._model, broad_phase="explicit")
+                if cls._collision_cfg is not None:
+                    cfg_dict = cls._collision_cfg.to_dict()
+                    hydro_cfg = cfg_dict.pop("sdf_hydroelastic_config", None)
+                    if hydro_cfg:
+                        cfg_dict["sdf_hydroelastic_config"] = HydroelasticSDF.Config(**hydro_cfg)
+                    cls._collision_pipeline = CollisionPipeline(cls._model, **cfg_dict)
+                else:
+                    cls._collision_pipeline = CollisionPipeline(cls._model, broad_phase="explicit")
+
             if cls._contacts is None:
                 cls._contacts = cls._collision_pipeline.contacts()
 
@@ -592,19 +605,20 @@ def initialize_solver(cls) -> None:
             else:
                 raise ValueError(f"Invalid solver type: {cls._solver_type}")
 
+            # Store collision pipeline config
+            cls._collision_cfg = cfg.collision_cfg  # type: ignore[union-attr]
+
             # Determine if we need external collision detection
             # - SolverMuJoCo with use_mujoco_contacts=True: uses internal MuJoCo collision detection
             # - SolverMuJoCo with use_mujoco_contacts=False: needs Newton's unified collision pipeline
             # - Other solvers (XPBD, Featherstone): always need Newton's unified collision pipeline
             if isinstance(cls._solver, SolverMuJoCo):
-                # Handle both dict and object configs
-                if hasattr(solver_cfg, "use_mujoco_contacts"):
-                    use_mujoco_contacts = solver_cfg.use_mujoco_contacts
-                elif isinstance(solver_cfg, dict):
-                    use_mujoco_contacts = solver_cfg.get("use_mujoco_contacts", False)
-                else:
-                    use_mujoco_contacts = getattr(solver_cfg, "use_mujoco_contacts", False)
-                cls._needs_collision_pipeline = not use_mujoco_contacts
+                cls._needs_collision_pipeline = not solver_cfg.use_mujoco_contacts
+                if solver_cfg.use_mujoco_contacts and cls._collision_cfg is not None:
+                    raise ValueError(
+                        "NewtonManager: collision_cfg cannot be set when use_mujoco_contacts=True."
+                        " Either set use_mujoco_contacts=False or remove collision_cfg."
+                    )
             else:
                 cls._needs_collision_pipeline = True
 

source/isaaclab_newton/isaaclab_newton/physics/newton_manager_cfg.py

@@ -12,8 +12,10 @@
 from isaaclab.physics import PhysicsCfg
 from isaaclab.utils import configclass
 
+from .newton_collision_cfg import NewtonCollisionPipelineCfg
+
 if TYPE_CHECKING:
-    from .newton_manager import NewtonManager
+    from isaaclab_newton.physics import NewtonManager
 
 
 @configclass
@@ -104,7 +106,27 @@ class MJWarpSolverCfg(NewtonSolverCfg):
     """Whether to use parallel line search."""
 
     use_mujoco_contacts: bool = True
-    """Whether to use MuJoCo's contact solver."""
+    """Whether to use MuJoCo's internal contact solver.
+
+    If ``True`` (default), MuJoCo handles collision detection and contact resolution internally.
+    If ``False``, Newton's :class:`CollisionPipeline` is used instead.  A default pipeline
+    (``broad_phase="explicit"``) is created automatically when :attr:`NewtonCfg.collision_cfg`
+    is ``None``.  Set :attr:`NewtonCfg.collision_cfg` to a :class:`NewtonCollisionPipelineCfg`
+    to customize pipeline parameters (broad phase, contact limits, hydroelastic, etc.).
+
+    .. note::
+        Setting ``collision_cfg`` while ``use_mujoco_contacts=True`` raises
+        :class:`ValueError` because the two collision modes are mutually exclusive.
+    """
+
+    tolerance: float = 1e-6
+    """Solver convergence tolerance for the constraint residual.
+
+    The solver iterates until the residual drops below this threshold or
+    ``iterations`` is reached.  Lower values give more precise constraint
+    satisfaction at the cost of more iterations.  MuJoCo default is ``1e-8``;
+    Newton default is ``1e-6``.
+    """
 
 
 @configclass
@@ -218,3 +240,20 @@ class NewtonCfg(PhysicsCfg):
 
     solver_cfg: NewtonSolverCfg = MJWarpSolverCfg()
     """Solver configuration. Default is MJWarpSolverCfg()."""
+
+    collision_cfg: NewtonCollisionPipelineCfg | None = None
+    """Newton collision pipeline configuration.
+
+    Controls how Newton's :class:`CollisionPipeline` is configured when it is active.
+    The pipeline is active when:
+
+    - :class:`MJWarpSolverCfg` with ``use_mujoco_contacts=False``, or
+    - any non-MuJoCo solver (:class:`XPBDSolverCfg`, :class:`FeatherstoneSolverCfg`).
+
+    If ``None`` (default), a pipeline with ``broad_phase="explicit"`` is created
+    automatically.  Set this to a :class:`NewtonCollisionPipelineCfg` to customize
+    parameters such as broad phase algorithm, contact limits, or hydroelastic mode.
+
+    .. note::
+        Must not be set when ``use_mujoco_contacts=True`` (raises :class:`ValueError`).
+    """