Material Options

A material selects the solver that simulates an entity and that solver's physical parameters: rigid (and kinematic) bodies, MPM, SPH, PBD and FEM deformables, and the Eden-hosted Mochi solver. Set it as an entity's material field. The physics guide explains each solver.

from eden.options.materials import RigidMaterialOptions

RigidMaterialOptions(gravity_compensation=1.0)  # gravity compensation is a material field

A Mochi scene is all-Mochi: every entity, the ground plane included, takes a Mochi*MaterialOptions.

Material options for rigid, MPM, SPH, FEM, PBD, and Mochi entities.

Attributes

MaterialLike module-attribute

MaterialLike: TypeAlias = RigidMaterialOptions | KinematicMaterialOptions | MPMElasticMaterialOptions | MPMElastoPlasticMaterialOptions | MPMLiquidMaterialOptions | MPMSandMaterialOptions | SPHLiquidMaterialOptions | PBDLiquidMaterialOptions | PBDClothMaterialOptions | PBDElasticMaterialOptions | PBDParticleMaterialOptions | FEMElasticMaterialOptions | FEMClothMaterialOptions | FEMMuscleMaterialOptions | MochiRigidMaterialOptions | MochiElasticMaterialOptions | MochiShellMaterialOptions | MochiRodMaterialOptions

Union of every concrete material options class.

Classes

MaterialOptions

MaterialOptions(**data)

Bases: ConfigurableOptions

Options for Genesis materials.

Subclasses set _genesis_material_cls to the corresponding gs.materials.* class; to_genesis_material then forwards every declared field through.

PARAMETER	DESCRIPTION
use_visual_raycasting	If True, the entity's visual mesh is included in the raycaster BVH used by Lidar / DepthCamera sensors, and by a viewer plugin casting against visual geometry (MeshPointSelectorPlugin(use_visual_geom=True)). Required for non-colliding background meshes (e.g. photogrammetry GLBs with collision=False) to be hit by lidar rays. Must be set before scene.build(). Default is False. TYPE: bool

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

use_visual_raycasting class-attribute instance-attribute

use_visual_raycasting: bool = False

Methods:

to_genesis_material

to_genesis_material()

Source code in eden/options/materials.py

def to_genesis_material(self):
    cls = self._genesis_material_cls
    if cls is None:
        raise NotImplementedError(f"{type(self).__name__} does not implement to_genesis_material()")
    # Drop None-valued fields so Genesis applies its own (often lazily-resolved)
    # defaults rather than seeing an explicit ``None``. Several Genesis materials
    # reject an explicit ``sampler=None`` even though it is their ``__init__``
    # default (e.g. ``gs.materials.MPM.Elastic``), so forwarding None would make
    # ``MPMElasticMaterialOptions()`` unusable.
    return cls(**{k: v for k, v in self.dict().items() if v is not None})

KinematicMaterialOptions

KinematicMaterialOptions(**data)

Bases: MaterialOptions

Options for Genesis kinematic materials.

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

RigidMaterialOptions

RigidMaterialOptions(**data)

Bases: MaterialOptions

Options for Genesis rigid materials.

PARAMETER	DESCRIPTION
rho	The density of the material used to compute mass. Default is 200.0. TYPE: float
friction	Friction coefficient within the rigid solver. If None, a default of 1.0 may be used or parsed from file. TYPE: float
friction_torsional	Torsional friction coefficient: how strongly a contact resists relative spin about its normal. Expressed in meters — it is the effective contact-patch radius, and it bounds the resisting torque at friction_torsional * normal_force. Requires EnvOptions.enable_torsional_friction (Eden raises at build if the switch is off) and costs one extra constraint axis per contact. If None, parsed from the asset when available (MJCF friction[1], only for geoms declaring condim >= 4), otherwise genesis' 0.005. Default is None. TYPE: float
friction_rolling	Rolling friction coefficient: how strongly a contact resists rolling about its two tangent axes. In meters like friction_torsional. Requires EnvOptions.enable_rolling_friction (which itself requires enable_torsional_friction) and costs two extra constraint axes per contact. If None, parsed from the asset when available (MJCF friction[2], only for geoms declaring condim >= 6), otherwise genesis' 0.0001. Default is None. TYPE: float
needs_coup	Whether the material participates in coupling with other solvers. Default is True. TYPE: bool
coup_friction	Friction used during coupling. Must be non-negative. Default is 0.1. TYPE: float
coup_softness	Softness of coupling interaction. Must be non-negative. Default is 0.002. TYPE: float
coup_restitution	Restitution coefficient in collision coupling. Should be between 0 and 1. Default is 0.0. TYPE: float
sdf_cell_size	Cell size in SDF grid in meters. Defines grid resolution. Default is 0.005. TYPE: float
sdf_min_res	Minimum resolution of the SDF grid. Must be at least 16. Default is 32. TYPE: int
sdf_max_res	Maximum resolution of the SDF grid. Must be >= sdf_min_res. Default is 128. TYPE: int
gravity_compensation	Compensation factor for gravity. 1.0 cancels gravity. Default is 0. TYPE: float
coup_type	Coupling mode for this entity. Only used by the IPC coupler. Requires needs_coup=True. If None, auto-selected based on entity type: 'external_articulation' for fixed-base articulated robots, 'two_way_soft_constraint' for floating-base robots, and 'ipc_only' for non-articulated objects. Valid values: - 'two_way_soft_constraint': Two-way soft coupling. - 'external_articulation': Joint-level coupling for articulated bodies. Joint positions will be coupled at the DOF level. - 'ipc_only': IPC controls entity, transforms copied to Genesis (one-way). Only supported by rigid non-articulated objects. Default is None. TYPE: str or None
coup_links	Link names to include in coupling. When set, only the named links participate in coupling; other links are excluded. Only supported with needs_coup=True and two_way_soft_constraint type in IPC. Default is None. TYPE: list of str or None
enable_coup_collision	Whether coupler collision is enabled for this entity's links. Only used by the IPC coupler. Unlike needs_coup=False (which removes the entity from the coupler entirely), setting this to False keeps the entity in the coupler for coupling forces but disables contact response. Default is True. TYPE: bool
coup_collision_links	Link names whose geoms participate in coupler collision. Only used by the IPC coupler. Only effective when enable_coup_collision=True. If None, all coupled links have collision. When set, only the named links get coupler collision; other links are marked no-collision. Default is None. TYPE: list of str or None
contact_resistance	IPC coupling contact resistance/stiffness override for this entity. None means use IPCCouplerOptions.contact_resistance. Default is None. TYPE: float or None

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

rho class-attribute instance-attribute

rho: float = 200.0

friction class-attribute instance-attribute

friction: float | None = None

friction_torsional class-attribute instance-attribute

friction_torsional: float | None = Field(default=None, ge=0.0)

friction_rolling class-attribute instance-attribute

friction_rolling: float | None = Field(default=None, ge=0.0)

needs_coup class-attribute instance-attribute

needs_coup: bool = True

coup_friction class-attribute instance-attribute

coup_friction: float = 0.1

coup_softness class-attribute instance-attribute

coup_softness: float = 0.002

coup_restitution class-attribute instance-attribute

coup_restitution: float = 0.0

sdf_cell_size class-attribute instance-attribute

sdf_cell_size: float = 0.005

sdf_min_res class-attribute instance-attribute

sdf_min_res: int = 32

sdf_max_res class-attribute instance-attribute

sdf_max_res: int = 128

gravity_compensation class-attribute instance-attribute

gravity_compensation: float = 0.0

coup_type class-attribute instance-attribute

coup_type: Literal['two_way_soft_constraint', 'external_articulation', 'ipc_only'] | None = None

coup_links class-attribute instance-attribute

coup_links: list[str] | None = None

enable_coup_collision class-attribute instance-attribute

enable_coup_collision: bool = True

coup_collision_links class-attribute instance-attribute

coup_collision_links: list[str] | None = None

contact_resistance class-attribute instance-attribute

contact_resistance: float | None = None

MPMElasticMaterialOptions

MPMElasticMaterialOptions(**data)

Bases: MaterialOptions

Options for Genesis MPM elastic materials.

PARAMETER	DESCRIPTION
E	Young's modulus. Default is 3e5.
nu	Poisson ratio. Default is 0.2.
rho	Density (kg/m^3). Default is 1000.
lam	The first Lame's parameter. Default is None, computed by E and nu.
mu	The second Lame's parameter. Default is None, computed by E and nu.
sampler	Particle sampler ('pbs', 'regular', 'random'). Note that 'pbs' is only supported on Linux x86 for now. Defaults to 'pbs' on supported platforms, 'random' otherwise.
model	Stress model ('corotation', 'neohooken'). Default is 'corotation'.

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

E class-attribute instance-attribute

E: float = 300000.0

nu class-attribute instance-attribute

nu: float = 0.2

rho class-attribute instance-attribute

rho: float = 1000.0

lam class-attribute instance-attribute

lam: float | None = None

mu class-attribute instance-attribute

mu: float | None = None

sampler class-attribute instance-attribute

sampler: str | None = None

model class-attribute instance-attribute

model: Literal['corotation', 'neohooken'] = 'corotation'

MPMElastoPlasticMaterialOptions

MPMElastoPlasticMaterialOptions(**data)

Bases: MaterialOptions

Options for an MPM elasto-plastic material.

PARAMETER	DESCRIPTION
E	Young's modulus. Default is 1e6.
nu	Poisson ratio. Default is 0.2.
rho	Density (kg/m^3). Default is 1000.
lam	The first Lame's parameter. Default is None, computed by E and nu.
mu	The second Lame's parameter. Default is None, computed by E and nu.
sampler	Particle sampler ('pbs', 'regular', 'random'). Note that 'pbs' is only supported on Linux x86 for now. Defaults to 'pbs' on supported platforms, 'random' otherwise.
yield_lower	Lower bound for the yield clamp (ignored if using von Mises). Default is 2.5e-2.
yield_higher	Upper bound for the yield clamp (ignored if using von Mises). Default is 4.5e-2.
use_von_mises	Whether to use von Mises yield criterion. Default is True.
von_mises_yield_stress	Yield stress for von Mises criterion. Default is 10000.

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

E class-attribute instance-attribute

E: float = 1000000.0

nu class-attribute instance-attribute

nu: float = 0.2

rho class-attribute instance-attribute

rho: float = 1000.0

lam class-attribute instance-attribute

lam: float | None = None

mu class-attribute instance-attribute

mu: float | None = None

sampler class-attribute instance-attribute

sampler: str | None = None

yield_lower class-attribute instance-attribute

yield_lower: float = 0.025

yield_higher class-attribute instance-attribute

yield_higher: float = 0.045

use_von_mises class-attribute instance-attribute

use_von_mises: bool = True

von_mises_yield_stress class-attribute instance-attribute

von_mises_yield_stress: float = 10000.0

MPMLiquidMaterialOptions

MPMLiquidMaterialOptions(**data)

Bases: MaterialOptions

Options for an MPM liquid material.

PARAMETER	DESCRIPTION
E	Young's modulus. Default is 1e6.
nu	Poisson ratio. Default is 0.2.
rho	Density (kg/m^3). Default is 1000.
lam	The first Lame's parameter. Default is None, computed by E and nu.
mu	The second Lame's parameter. Default is None, computed by E and nu.
viscous	Whether the liquid is viscous. Simply set mu to zero when non-viscous. Default is False.
sampler	Particle sampler ('pbs', 'regular', 'random'). Note that 'pbs' is only supported on Linux x86 for now. Defaults to 'pbs' on supported platforms, 'random' otherwise.

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

E class-attribute instance-attribute

E: float = 1000000.0

nu class-attribute instance-attribute

nu: float = 0.2

rho class-attribute instance-attribute

rho: float = 1000.0

lam class-attribute instance-attribute

lam: float | None = None

mu class-attribute instance-attribute

mu: float | None = None

viscous class-attribute instance-attribute

viscous: bool = False

sampler class-attribute instance-attribute

sampler: str | None = None

MPMSandMaterialOptions

MPMSandMaterialOptions(**data)

Bases: MaterialOptions

Options for an MPM sand (granular) material.

PARAMETER	DESCRIPTION
E	Young's modulus. Default is 1e6.
nu	Poisson ratio. Default is 0.2.
rho	Density (kg/m^3). Default is 1000.
lam	The first Lame's parameter. Default is None, computed by E and nu.
mu	The second Lame's parameter. Default is None, computed by E and nu.
friction_angle	Internal friction angle of the granular material (degrees). Default is 45.
sampler	Particle sampler ('pbs', 'regular', 'random'). Note that 'pbs' is only supported on Linux x86 for now. Defaults to 'pbs' on supported platforms, 'random' otherwise.

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

E class-attribute instance-attribute

E: float = 1000000.0

nu class-attribute instance-attribute

nu: float = 0.2

rho class-attribute instance-attribute

rho: float = 1000.0

lam class-attribute instance-attribute

lam: float | None = None

mu class-attribute instance-attribute

mu: float | None = None

friction_angle class-attribute instance-attribute

friction_angle: float = 45.0

sampler class-attribute instance-attribute

sampler: str | None = None

SPHLiquidMaterialOptions

SPHLiquidMaterialOptions(**data)

Bases: MaterialOptions

Options for an SPH liquid material.

PARAMETER	DESCRIPTION
rho	The rest density (kg/m^3) the material tends to maintain in equilibrium. Default is 1000.
stiffness	State stiffness (N/m^2): how pressure increases with compression. Default is 50000.0.
exponent	State exponent: how nonlinearly pressure scales with density. Larger values mean a stiffer response to compression. Default is 7.0.
mu	The viscosity of the liquid. Default is 0.005.
gamma	The surface tension of the liquid: how strongly the material "clumps" together at boundaries. Default is 0.01.
sampler	Particle sampler ('pbs', 'regular', 'random'). 'pbs' is only supported on Linux x86. Default is 'regular': SPH is sensitive to the initial particle distribution, which sets the initial density and pressure fields. Irregular samplers ('pbs', 'random') introduce local density fluctuations at initialization, which cause large spurious pressure forces and can make the simulation unstable or diverge.

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

rho class-attribute instance-attribute

rho: float = 1000.0

stiffness class-attribute instance-attribute

stiffness: float = 50000.0

exponent class-attribute instance-attribute

exponent: float = 7.0

mu class-attribute instance-attribute

mu: float = 0.005

gamma class-attribute instance-attribute

gamma: float = 0.01

sampler class-attribute instance-attribute

sampler: str = 'regular'

PBDLiquidMaterialOptions

PBDLiquidMaterialOptions(**data)

Bases: MaterialOptions

Options for Genesis PBD (Position-Based Dynamics) liquid materials.

Particle-based fluid simulated with the PBD solver. The PBD solver's simulation domain (lower_bound/upper_bound) and iteration counts are configured via EnvOptions.pbd_options (a gs.options.PBDOptions). If left unset, genesis uses its PBD defaults (a (-100, -100, 0)..(100, 100, 100) domain) — set it to bound the domain to the working volume. Position/orientation are baked into the morph at creation time (set_pos/set_quat raise on the resulting entity).

PARAMETER	DESCRIPTION
rho	Rest density of the fluid. Default is 1000.0. TYPE: float
sampler	Particle sampler ('pbs', 'random', 'regular'). 'pbs' is only supported on Linux x86. Default is 'pbs'. TYPE: str
density_relaxation	Relaxation factor for the density (incompressibility) constraint. Larger values enforce incompressibility more strongly per iteration. Default is 0.2. TYPE: float
viscosity_relaxation	Relaxation factor for the XSPH viscosity constraint. Larger values make the fluid more viscous. Default is 0.01. TYPE: float

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

rho class-attribute instance-attribute

rho: float = 1000.0

sampler class-attribute instance-attribute

sampler: Literal['pbs', 'random', 'regular'] = 'pbs'

density_relaxation class-attribute instance-attribute

density_relaxation: float = 0.2

viscosity_relaxation class-attribute instance-attribute

viscosity_relaxation: float = 0.01

PBDClothMaterialOptions

PBDClothMaterialOptions(**data)

Bases: MaterialOptions

Options for Genesis PBD (Position-Based Dynamics) cloth materials.

Thin-shell cloth simulated as a particle/edge network with the PBD solver. Built from a triangle mesh morph (e.g. EntityOptions(file="meshes/cloth.obj")). The PBD solver iteration counts are configured via EnvOptions.pbd_options (genesis defaults are used if unset). Individual particles can be pinned via the underlying Genesis entity's fix_particles / find_closest_particle (accessible through entity.entity).

PARAMETER	DESCRIPTION
rho	Surface density of the cloth. Default is 4.0. TYPE: float
static_friction	Static friction coefficient for particle contact. Default is 0.15. TYPE: float
kinetic_friction	Kinetic friction coefficient for particle contact. Default is 0.15. TYPE: float
stretch_compliance	Compliance (inverse stiffness) of the stretch constraint. Smaller values make the cloth less stretchy. Default is 1e-7. TYPE: float
bending_compliance	Compliance (inverse stiffness) of the bending constraint. Smaller values make the cloth resist folding more. Default is 1e-5. TYPE: float
stretch_relaxation	Relaxation factor for the stretch constraint per iteration. Default is 0.3. TYPE: float
bending_relaxation	Relaxation factor for the bending constraint per iteration. Default is 0.1. TYPE: float
air_resistance	Air drag applied to the cloth particles. Default is 0.001. TYPE: float

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

rho class-attribute instance-attribute

rho: float = 4.0

static_friction class-attribute instance-attribute

static_friction: float = 0.15

kinetic_friction class-attribute instance-attribute

kinetic_friction: float = 0.15

stretch_compliance class-attribute instance-attribute

stretch_compliance: float = 1e-07

bending_compliance class-attribute instance-attribute

bending_compliance: float = 1e-05

stretch_relaxation class-attribute instance-attribute

stretch_relaxation: float = 0.3

bending_relaxation class-attribute instance-attribute

bending_relaxation: float = 0.1

air_resistance class-attribute instance-attribute

air_resistance: float = 0.001

PBDElasticMaterialOptions

PBDElasticMaterialOptions(**data)

Bases: MaterialOptions

Options for Genesis PBD (Position-Based Dynamics) elastic (soft-body) materials.

Volumetric soft body simulated with the PBD solver, governed by stretch, bending, and volume-preservation constraints. The PBD solver is configured via EnvOptions.pbd_options (genesis defaults are used if unset).

PARAMETER	DESCRIPTION
rho	Material density. Default is 1000.0. TYPE: float
static_friction	Static friction coefficient for particle contact. Default is 0.15. TYPE: float
kinetic_friction	Kinetic friction coefficient for particle contact. Default is 0.15. TYPE: float
stretch_compliance	Compliance (inverse stiffness) of the stretch constraint. Default is 0.0. TYPE: float
bending_compliance	Compliance (inverse stiffness) of the bending constraint. Default is 0.0. TYPE: float
volume_compliance	Compliance (inverse stiffness) of the volume-preservation constraint. Default is 0.0. TYPE: float
stretch_relaxation	Relaxation factor for the stretch constraint per iteration. Default is 0.1. TYPE: float
bending_relaxation	Relaxation factor for the bending constraint per iteration. Default is 0.1. TYPE: float
volume_relaxation	Relaxation factor for the volume constraint per iteration. Default is 0.1. TYPE: float

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

rho class-attribute instance-attribute

rho: float = 1000.0

static_friction class-attribute instance-attribute

static_friction: float = 0.15

kinetic_friction class-attribute instance-attribute

kinetic_friction: float = 0.15

stretch_compliance class-attribute instance-attribute

stretch_compliance: float = 0.0

bending_compliance class-attribute instance-attribute

bending_compliance: float = 0.0

volume_compliance class-attribute instance-attribute

volume_compliance: float = 0.0

stretch_relaxation class-attribute instance-attribute

stretch_relaxation: float = 0.1

bending_relaxation class-attribute instance-attribute

bending_relaxation: float = 0.1

volume_relaxation class-attribute instance-attribute

volume_relaxation: float = 0.1

PBDParticleMaterialOptions

PBDParticleMaterialOptions(**data)

Bases: MaterialOptions

Options for Genesis PBD (Position-Based Dynamics) free-particle materials.

Bare particles driven by the PBD solver with no internal constraints (collide and respond to gravity only). The PBD solver is configured via EnvOptions.pbd_options (genesis defaults are used if unset).

PARAMETER	DESCRIPTION
rho	Material density. Default is 1000.0. TYPE: float
sampler	Particle sampler ('pbs', 'random', 'regular'). 'pbs' is only supported on Linux x86. Default is 'pbs'. TYPE: str

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

rho class-attribute instance-attribute

rho: float = 1000.0

sampler class-attribute instance-attribute

sampler: Literal['pbs', 'random', 'regular'] = 'pbs'

FEMElasticMaterialOptions

FEMElasticMaterialOptions(**data)

Bases: MaterialOptions

Options for Genesis FEM elastic materials.

Used for volumetric deformable bodies (tetrahedralized meshes) simulated with the FEM solver. When an IPC coupler is active, these entities participate in penetration-free frictional contact.

PARAMETER	DESCRIPTION
E	Young's modulus controlling stiffness. Default is 1e6. TYPE: float
nu	Poisson ratio describing volume change under stress. Default is 0.2. TYPE: float
rho	Material density (kg/m^3). Default is 1000. TYPE: float
model	Constitutive model ('linear', 'stable_neohookean', 'linear_corotated'). Default is 'linear'. TYPE: str
friction_mu	Friction coefficient. Default is 0.1. TYPE: float
contact_resistance	IPC contact resistance/stiffness override. None uses the coupler global default. Default is None. TYPE: float or None

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

E class-attribute instance-attribute

E: float = 1000000.0

nu class-attribute instance-attribute

nu: float = 0.2

rho class-attribute instance-attribute

rho: float = 1000.0

model class-attribute instance-attribute

model: Literal['linear', 'stable_neohookean', 'linear_corotated'] = 'linear'

friction_mu class-attribute instance-attribute

friction_mu: float = 0.1

contact_resistance class-attribute instance-attribute

contact_resistance: float | None = None

FEMClothMaterialOptions

FEMClothMaterialOptions(**data)

Bases: MaterialOptions

Options for Genesis FEM cloth (thin shell) materials.

Used for cloth, fabric, and thin flexible surfaces simulated as 2D shells in the IPC backend. Requires an IPC coupler and GPU backend.

PARAMETER	DESCRIPTION
E	Young's modulus (Pa) controlling stiffness. Default is 1e4. TYPE: float
nu	Poisson ratio. Default is 0.49 (nearly incompressible). TYPE: float
rho	Material density (kg/m^3). Default is 200. TYPE: float
thickness	Shell thickness in meters. Default is 0.001 (1mm). TYPE: float
bending_stiffness	Bending resistance. None disables bending. Default is None. TYPE: float or None
model	FEM material model. Default is 'stable_neohookean'. TYPE: str
friction_mu	Friction coefficient. Default is 0.1. TYPE: float
contact_resistance	IPC contact resistance/stiffness override. None uses the coupler global default. Default is None. TYPE: float or None

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

E class-attribute instance-attribute

E: float = 10000.0

nu class-attribute instance-attribute

nu: float = 0.49

rho class-attribute instance-attribute

rho: float = 200.0

thickness class-attribute instance-attribute

thickness: float = 0.001

bending_stiffness class-attribute instance-attribute

bending_stiffness: float | None = None

model class-attribute instance-attribute

model: Literal['linear', 'stable_neohookean', 'linear_corotated'] = 'stable_neohookean'

friction_mu class-attribute instance-attribute

friction_mu: float = 0.1

contact_resistance class-attribute instance-attribute

contact_resistance: float | None = None

FEMMuscleMaterialOptions

FEMMuscleMaterialOptions(**data)

Bases: MaterialOptions

Options for Genesis FEM muscle materials.

Extends FEM elastic material with muscle activation support for soft-body actuation.

PARAMETER	DESCRIPTION
E	Young's modulus. Default is 1e6. TYPE: float
nu	Poisson ratio. Default is 0.2. TYPE: float
rho	Material density (kg/m^3). Default is 1000. TYPE: float
model	Constitutive model. Default is 'linear'. TYPE: str
n_groups	Number of muscle groups. Default is 1. TYPE: int
friction_mu	Friction coefficient. Default is 0.1. TYPE: float
contact_resistance	IPC contact resistance/stiffness override. Default is None. TYPE: float or None

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

E class-attribute instance-attribute

E: float = 1000000.0

nu class-attribute instance-attribute

nu: float = 0.2

rho class-attribute instance-attribute

rho: float = 1000.0

model class-attribute instance-attribute

model: Literal['linear', 'stable_neohookean', 'linear_corotated'] = 'linear'

n_groups class-attribute instance-attribute

n_groups: int = 1

friction_mu class-attribute instance-attribute

friction_mu: float = 0.1

contact_resistance class-attribute instance-attribute

contact_resistance: float | None = None

MochiMaterialOptions

MochiMaterialOptions(**data)

Bases: MaterialOptions

Base of every Mochi (implicit multi-physics solver) material.

Not usable directly — pick :class:MochiRigidMaterialOptions, :class:MochiElasticMaterialOptions, :class:MochiShellMaterialOptions or :class:MochiRodMaterialOptions. A scene holding one Mochi entity must hold only Mochi (and kinematic) entities: the MochiSolver assembles every body and the penalty contact into one Newton system and refuses to run beside another physics solver. The shared contact parameters below are combined per contact pair as documented on each field.

PARAMETER	DESCRIPTION
use_visual_raycasting	See :class:MaterialOptions. Default is False. TYPE: bool

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

friction class-attribute instance-attribute

friction: float = 0.5

penalty_coefficient class-attribute instance-attribute

penalty_coefficient: float = 1000000000.0

penalty_smoothing_half_distance class-attribute instance-attribute

penalty_smoothing_half_distance: float = 0.005

penalty_threshold class-attribute instance-attribute

penalty_threshold: float = 0.001

friction_falloff_vel class-attribute instance-attribute

friction_falloff_vel: float = 0.01

viscous_friction class-attribute instance-attribute

viscous_friction: float = 0.0

normal_viscous_damping class-attribute instance-attribute

normal_viscous_damping: float = 0.0

max_alignment_normals class-attribute instance-attribute

max_alignment_normals: float = 0.0

has_gravity class-attribute instance-attribute

has_gravity: bool = True

contact_layer class-attribute instance-attribute

contact_layer: str = 'default'

MochiRigidMaterialOptions

MochiRigidMaterialOptions(**data)

Bases: MochiMaterialOptions

Options for Mochi rigid and articulated bodies (eden.engine.solvers.mochi.materials.Rigid).

Deliberately not a :class:RigidMaterialOptions: the Mochi solver has no coupler, so the coup_* / gravity_compensation / needs_coup fields do not exist here (Genesis rejects them on Mochi.Rigid; gravity is switched per body with has_gravity). Entities carrying this material build as :class:~eden.entities.mochi.MochiRigidEntity, which keeps the whole rigid-entity API (DOFs, PD control, IK, attach_to) minus force ranges, friction loss and constraint-solver parameters, which the solver never reads.

PARAMETER	DESCRIPTION
use_visual_raycasting	See :class:MaterialOptions. Default is False. TYPE: bool
rho	Density (kg/m^3) used to derive mass and inertia when the asset gives none; overrides per-geometry densities declared in the asset. Default is 1000.0. TYPE: float
collider_type	How other bodies collide against this one: an analytic plane/sphere/box, a signed distance field of the mesh, or nothing. "auto" picks from the morph. An analytic field needs the matching primitive morph (the solver raises at build otherwise). Default is "auto". TYPE: ('auto', 'plane', 'sphere', 'box', 'sdf', 'none') DEFAULT: "auto"
sdf_cell_size	Cell size (m) of the SDF grid built for collider_type="sdf". Default is 2.5e-3. TYPE: float
sdf_min_res	Minimum SDF grid resolution. Default is 32. TYPE: int
sdf_max_res	Maximum SDF grid resolution. Default is 128. TYPE: int

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

rho class-attribute instance-attribute

rho: float = 1000.0

collider_type class-attribute instance-attribute

collider_type: Literal['auto', 'plane', 'sphere', 'box', 'sdf', 'none'] = 'auto'

sdf_cell_size class-attribute instance-attribute

sdf_cell_size: float = 0.0025

sdf_min_res class-attribute instance-attribute

sdf_min_res: int = 32

sdf_max_res class-attribute instance-attribute

sdf_max_res: int = 128

MochiElasticMaterialOptions

MochiElasticMaterialOptions(**data)

Bases: MochiMaterialOptions

Options for Mochi volumetric soft bodies (eden.engine.solvers.mochi.materials.Elastic).

Linear tetrahedra with a stable neo-Hookean, Saint Venant-Kirchhoff or linear material, solved fully implicitly together with contact. Box / Sphere / Cylinder / Mesh morphs are tetrahedralized by tetgen (pass morph={"maxvolume": ..., "nobisect": False} on the primitive to refine); a .node (tetgen) or .vtk (legacy ASCII unstructured grid) file is read as-is. Entities build as :class:~eden.entities.mochi.MochiSoftEntity.

PARAMETER	DESCRIPTION
use_visual_raycasting	See :class:MaterialOptions. Default is False. TYPE: bool
E	Young's modulus (Pa). Default is 1e5. TYPE: float
nu	Poisson ratio. Default is 0.45. TYPE: float
rho	Density (kg/m^3). Default is 1000.0. TYPE: float
model	Constitutive model. Default is "stable_neohookean". TYPE: ('stable_neohookean', 'stvk', 'linear') DEFAULT: "stable_neohookean"
mass_damping	Rayleigh mass-proportional damping (1/s). Default is 0.0. TYPE: float
stiffness_damping	Rayleigh stiffness-proportional damping (s). Default is 0.0. TYPE: float
collider_type	How other bodies collide against this body: a signed distance field of the rest shape queried through the deformed tetrahedra (no contact skin — a few millimeters of interpenetration remain), or nothing. Default is "auto". TYPE: ('auto', 'sdf', 'none') DEFAULT: "auto"

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

E class-attribute instance-attribute

E: float = 100000.0

nu class-attribute instance-attribute

nu: float = 0.45

rho class-attribute instance-attribute

rho: float = 1000.0

model class-attribute instance-attribute

model: Literal['stable_neohookean', 'stvk', 'linear'] = 'stable_neohookean'

mass_damping class-attribute instance-attribute

mass_damping: float = 0.0

stiffness_damping class-attribute instance-attribute

stiffness_damping: float = 0.0

collider_type class-attribute instance-attribute

collider_type: Literal['auto', 'sdf', 'none'] = 'auto'

MochiShellMaterialOptions

MochiShellMaterialOptions(**data)

Bases: MochiMaterialOptions

Options for Mochi thin shells / cloth (eden.engine.solvers.mochi.materials.Shell).

The surface triangles of a Mesh (or primitive) morph become a Saint Venant-Kirchhoff membrane plus a Koiter-type bending term, both thickness-integrated from E, nu, rho and thickness unless overridden. Shells act as colliders through spheres of collider_radius at their vertices, which only other point-cloud bodies (cloths, rods) and — with self_contact — the shell itself feel; rigid bodies and solids touch the shell through its own contact samples. Consistently wound meshes are required. Light cloth has little inertia: use penalty_coefficient=1e7. Entities build as :class:~eden.entities.mochi.MochiSoftEntity.

PARAMETER	DESCRIPTION
use_visual_raycasting	See :class:MaterialOptions. Default is False. TYPE: bool
E	Young's modulus (Pa). Default is 1e4. TYPE: float
nu	Poisson ratio. Default is 0.3. TYPE: float
rho	Density (kg/m^3); areal density is rho * thickness. Default is 200.0. TYPE: float
thickness	Shell thickness (m). Default is 1e-3. TYPE: float
membrane_mu	Membrane shear stiffness override; None derives thickness * mu. Default is None. TYPE: float or None
membrane_lambda	Membrane Lame lambda override (plane stress); None derives it. Default is None. TYPE: float or None
bending_alpha	Bending stiffness override, D * nu when None. Default is None. TYPE: float or None
bending_beta	Bending stiffness override, D * (1 - nu) when None. Default is None. TYPE: float or None
mass_damping	Rayleigh mass-proportional damping (1/s). Default is 0.0. TYPE: float
stiffness_damping	Rayleigh stiffness-proportional damping (s). Default is 0.0. TYPE: float
collider_type	Whether the shell carries vertex spheres other point-cloud bodies collide with. Default is "auto". TYPE: ('auto', 'point_cloud', 'none') DEFAULT: "auto"
collider_radius	Radius (m) of the vertex spheres. Default is 1e-2. TYPE: float
self_contact	Let the shell's samples collide with its own vertex spheres. Default is False. TYPE: bool
self_contact_exclusion_ratio	Vertices within collider_radius * ratio (plus the penalty threshold) of a sample in the rest configuration are excluded from self-contact. Default is 1.5. TYPE: float

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

E class-attribute instance-attribute

E: float = 10000.0

nu class-attribute instance-attribute

nu: float = 0.3

rho class-attribute instance-attribute

rho: float = 200.0

thickness class-attribute instance-attribute

thickness: float = 0.001

membrane_mu class-attribute instance-attribute

membrane_mu: float | None = None

membrane_lambda class-attribute instance-attribute

membrane_lambda: float | None = None

bending_alpha class-attribute instance-attribute

bending_alpha: float | None = None

bending_beta class-attribute instance-attribute

bending_beta: float | None = None

mass_damping class-attribute instance-attribute

mass_damping: float = 0.0

stiffness_damping class-attribute instance-attribute

stiffness_damping: float = 0.0

collider_type class-attribute instance-attribute

collider_type: Literal['auto', 'point_cloud', 'none'] = 'auto'

collider_radius class-attribute instance-attribute

collider_radius: float = 0.01

self_contact class-attribute instance-attribute

self_contact: bool = False

self_contact_exclusion_ratio class-attribute instance-attribute

self_contact_exclusion_ratio: float = 1.5

MochiRodMaterialOptions

MochiRodMaterialOptions(**data)

Bases: MochiMaterialOptions

Options for Mochi discrete elastic rods (eden.engine.solvers.mochi.materials.Rod).

A Kirchhoff rod (stretch, bend, twist; no shear) on the polyline of a :class:~eden.options.entities.RodOptions morph — the only morph this material accepts. The five stiffness / inertia quantities derive from E, nu, rho and the rod radius unless given explicitly. Clamp a rod by fixing its first two nodes. Rods collide through samples on their centerline and act as colliders through node spheres of the rod radius, which only other point-cloud bodies (and the rod itself under self_contact) feel. Entities build as :class:~eden.entities.mochi.MochiSoftEntity.

PARAMETER	DESCRIPTION
use_visual_raycasting	See :class:MaterialOptions. Default is False. TYPE: bool
E	Young's modulus (Pa). Default is 1e7. TYPE: float
nu	Poisson ratio (shear modulus G = E / (2 (1 + nu))). Default is 0.3. TYPE: float
rho	Density (kg/m^3). Default is 1000.0. TYPE: float
axial_stiffness	E * A override. Default is None. TYPE: float or None
flexural_stiffness	E * I override. Default is None. TYPE: float or None
torsional_stiffness	G * J override. Default is None. TYPE: float or None
linear_density	rho * A override (kg/m). Default is None. TYPE: float or None
linear_rotational_inertia	rho * J override (kg m). Default is None. TYPE: float or None
mass_damping	Rayleigh mass-proportional damping (1/s). Default is 0.0. TYPE: float
stiffness_damping	Rayleigh stiffness-proportional damping (s). Default is 0.0. TYPE: float
collider_type	Whether the rod carries node spheres other point-cloud bodies collide with. Default is "auto". TYPE: ('auto', 'point_cloud', 'none') DEFAULT: "auto"
self_contact	Let the rod's samples collide with its own node spheres. Default is False. TYPE: bool
self_contact_exclusion_ratio	Nodes within radius * ratio (plus the penalty threshold) of a sample in the rest configuration are excluded from self-contact; e.g. 3 for segments twice the radius. Default is 1.5. TYPE: float

Source code in eden/options/options.py

def __init__(self, **data):
    # Seed type metadata as construction data so BaseModel validates it into
    # __pydantic_extra__ (no-op for extra="forbid" classes, which use
    # the serialization envelope instead).
    data.update(option_metadata(self))
    # NOTE: all of the option modifications/validations should be done in the __init__ method
    try:
        BaseModel.__init__(self, **data)
    except ValidationError as exc:
        # A misspelled field on an extra="forbid" class should teach the field set, not just
        # name the typo. Only rewritten when every error is extra_forbidden.
        enriched = _enrich_extra_forbidden(type(self), exc)
        if enriched is None:
            raise
        raise enriched from None

Attributes

E class-attribute instance-attribute

E: float = 10000000.0

nu class-attribute instance-attribute

nu: float = 0.3

rho class-attribute instance-attribute

rho: float = 1000.0

axial_stiffness class-attribute instance-attribute

axial_stiffness: float | None = None

flexural_stiffness class-attribute instance-attribute

flexural_stiffness: float | None = None

torsional_stiffness class-attribute instance-attribute

torsional_stiffness: float | None = None

linear_density class-attribute instance-attribute

linear_density: float | None = None

linear_rotational_inertia class-attribute instance-attribute

linear_rotational_inertia: float | None = None

mass_damping class-attribute instance-attribute

mass_damping: float = 0.0

stiffness_damping class-attribute instance-attribute

stiffness_damping: float = 0.0

collider_type class-attribute instance-attribute

collider_type: Literal['auto', 'point_cloud', 'none'] = 'auto'

self_contact class-attribute instance-attribute

self_contact: bool = False

self_contact_exclusion_ratio class-attribute instance-attribute

self_contact_exclusion_ratio: float = 1.5

See also

• Physics guide
• Engine: MochiSolver