Source code for isaaclab_physx.sim.spawners.materials.physics_materials_cfg

# 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

from __future__ import annotations

import dataclasses
from collections.abc import Callable

from isaaclab.sim.spawners.materials import PhysicsMaterialCfg
from isaaclab.utils import configclass


@configclass
class OmniPhysicsDeformableMaterialCfg:
    """OmniPhysics material properties for a deformable body.

    These properties are set with the prefix ``omniphysics:<property_name>``. For example, to set the density of the
    deformable body, you would set the property ``omniphysics:density``.

    See the OmniPhysics documentation for more information on the available properties.
    """

    density: float | None = None
    """The material density in [kg/m^3]. Defaults to None, in which case the simulation decides the default density."""

    static_friction: float = 0.25
    """The static friction. Defaults to 0.25."""

    dynamic_friction: float = 0.25
    """The dynamic friction. Defaults to 0.25."""

    youngs_modulus: float = 1000000.0
    """The Young's modulus, which defines the body's stiffness. Defaults to 1[MPa].

    The Young's modulus is a measure of the material's ability to deform under stress. It is measured in Pascals ([Pa]).
    """

    poissons_ratio: float = 0.45
    """The Poisson's ratio which defines the body's volume preservation. Defaults to 0.45.

    The Poisson's ratio is a measure of the material's ability to expand in the lateral direction when compressed
    in the axial direction. It is a dimensionless number between 0 and 0.5. Using a value of 0.5 will make the
    material incompressible.
    """


@configclass
class OmniPhysicsSurfaceDeformableMaterialCfg(OmniPhysicsDeformableMaterialCfg):
    """OmniPhysics material properties for a surface deformable body,
    extending on :class:`OmniPhysicsDeformableMaterialCfg` with additional parameters for surface deformable bodies.

    These properties are set with the prefix ``omniphysics:<property_name>``.
    For example, to set the surface thickness of the surface deformable body,
    you would set the property ``omniphysics:surfaceThickness``.

    See the OmniPhysics documentation for more information on the available properties.
    """

    surface_thickness: float = 0.01
    """The thickness of the deformable body's surface. Defaults to 0.01 meters ([m])."""

    surface_stretch_stiffness: float = 0.0
    """The stretch stiffness of the deformable body's surface. Defaults to 0.0."""

    surface_shear_stiffness: float = 0.0
    """The shear stiffness of the deformable body's surface. Defaults to 0.0."""

    surface_bend_stiffness: float = 0.0
    """The bend stiffness of the deformable body's surface. Defaults to 0.0."""

    bend_damping: float = 0.0
    """The bend damping for the deformable body's surface. Defaults to 0.0."""


@configclass
class PhysXDeformableMaterialCfg:
    """PhysX-specific material properties for a deformable body.

    These properties are set with the prefix ``physxDeformableBody:<property_name>``.
    For example, to set the elasticity damping of the deformable body,
    you would set the property ``physxDeformableBody:elasticityDamping``.

    See the PhysX documentation for more information on the available properties.
    """

    elasticity_damping: float = 0.005
    """The elasticity damping for the deformable material. Defaults to 0.005."""




@configclass
class DeformableBodyMaterialCfg(PhysicsMaterialCfg, OmniPhysicsDeformableMaterialCfg, PhysXDeformableMaterialCfg):
    """Physics material parameters for deformable bodies.

    See :meth:`spawn_deformable_body_material` for more information.
    """

    func: Callable | str = "{DIR}.physics_materials:spawn_deformable_body_material"

    _property_prefix: dict[str, list[str]] = {
        "omniphysics": [field.name for field in dataclasses.fields(OmniPhysicsDeformableMaterialCfg)],
        "physxDeformableBody": [field.name for field in dataclasses.fields(PhysXDeformableMaterialCfg)],
    }
    """Mapping between the property prefixes and the properties that fall under each prefix."""





@configclass
class SurfaceDeformableBodyMaterialCfg(DeformableBodyMaterialCfg, OmniPhysicsSurfaceDeformableMaterialCfg):
    """Physics material parameters for surface deformable bodies,
    extending on :class:`DeformableBodyMaterialCfg` with additional parameters for surface deformable bodies.

    See :meth:`spawn_deformable_body_material` for more information.
    """

    func: Callable | str = "{DIR}.physics_materials:spawn_deformable_body_material"

    _property_prefix: dict[str, list[str]] = {
        "omniphysics": [field.name for field in dataclasses.fields(OmniPhysicsSurfaceDeformableMaterialCfg)],
        "physxDeformableBody": [field.name for field in dataclasses.fields(PhysXDeformableMaterialCfg)],
    }
    """Extend DeformableBodyMaterialCfg properties under each prefix."""