diff options
Diffstat (limited to 'src')
5 files changed, 31 insertions, 25 deletions
diff --git a/src/dynamics/integration_parameters.rs b/src/dynamics/integration_parameters.rs index 2d580e2..2de58ae 100644 --- a/src/dynamics/integration_parameters.rs +++ b/src/dynamics/integration_parameters.rs @@ -25,25 +25,31 @@ pub struct IntegrationParameters { pub min_ccd_dt: Real, /// > 0: the damping ratio used by the springs for contact constraint stabilization. - /// Lower values make the constraints more compliant (more "springy", allowing more visible + /// + /// Larger values make the constraints more compliant (allowing more visible /// penetrations before stabilization). /// (default `5.0`). pub contact_damping_ratio: Real, /// > 0: the natural frequency used by the springs for contact constraint regularization. + /// /// Increasing this value will make it so that penetrations get fixed more quickly at the /// expense of potential jitter effects due to overshooting. In order to make the simulation - /// look stiffer, it is recommended to increase the [`Self::damping_ratio`] instead of this + /// look stiffer, it is recommended to increase the [`Self::contact_damping_ratio`] instead of this /// value. /// (default: `30.0`). pub contact_natural_frequency: Real, /// > 0: the natural frequency used by the springs for joint constraint regularization. + /// /// Increasing this value will make it so that penetrations get fixed more quickly. /// (default: `1.0e6`). pub joint_natural_frequency: Real, /// The fraction of critical damping applied to the joint for constraints regularization. + /// + /// Larger values make the constraints more compliant (allowing more joint + /// drift before stabilization). /// (default `1.0`). pub joint_damping_ratio: Real, @@ -65,7 +71,7 @@ pub struct IntegrationParameters { /// /// This value can be understood as the number of units-per-meter in your physical world compared /// to a human-sized world in meter. For example, in a 2d game, if your typical object size is 100 - /// pixels, set the `[`Self::length_unit`]` parameter to 100.0. The physics engine will interpret + /// pixels, set the [`Self::length_unit`] parameter to 100.0. The physics engine will interpret /// it as if 100 pixels is equivalent to 1 meter in its various internal threshold. /// (default `1.0`). pub length_unit: Real, @@ -74,7 +80,7 @@ pub struct IntegrationParameters { /// /// This value is implicitly scaled by [`IntegrationParameters::length_unit`]. pub normalized_allowed_linear_error: Real, - /// Maximum amount of penetration the solver will attempt to resolve in one timestep. + /// Maximum amount of penetration the solver will attempt to resolve in one timestep (default: `10.0`). /// /// This value is implicitly scaled by [`IntegrationParameters::length_unit`]. pub normalized_max_corrective_velocity: Real, @@ -84,7 +90,7 @@ pub struct IntegrationParameters { pub normalized_prediction_distance: Real, /// The number of solver iterations run by the constraints solver for calculating forces (default: `4`). pub num_solver_iterations: NonZeroUsize, - /// Number of addition friction resolution iteration run during the last solver sub-step (default: `4`). + /// Number of addition friction resolution iteration run during the last solver sub-step (default: `0`). pub num_additional_friction_iterations: usize, /// Number of internal Project Gauss Seidel (PGS) iterations run at each solver iteration (default: `1`). pub num_internal_pgs_iterations: usize, @@ -130,23 +136,23 @@ impl IntegrationParameters { } /// The contact’s spring angular frequency for constraints regularization. - pub fn angular_frequency(&self) -> Real { + pub fn contact_angular_frequency(&self) -> Real { self.contact_natural_frequency * Real::two_pi() } - /// The [`Self::erp`] coefficient, multiplied by the inverse timestep length. - pub fn erp_inv_dt(&self) -> Real { - let ang_freq = self.angular_frequency(); + /// The [`Self::contact_erp`] coefficient, multiplied by the inverse timestep length. + pub fn contact_erp_inv_dt(&self) -> Real { + let ang_freq = self.contact_angular_frequency(); ang_freq / (self.dt * ang_freq + 2.0 * self.contact_damping_ratio) } /// The effective Error Reduction Parameter applied for calculating regularization forces /// on contacts. /// - /// This parameter is computed automatically from [`Self::natural_frequency`], - /// [`Self::damping_ratio`] and the substep length. - pub fn erp(&self) -> Real { - self.dt * self.erp_inv_dt() + /// This parameter is computed automatically from [`Self::contact_natural_frequency`], + /// [`Self::contact_damping_ratio`] and the substep length. + pub fn contact_erp(&self) -> Real { + self.dt * self.contact_erp_inv_dt() } /// The joint’s spring angular frequency for constraint regularization. @@ -171,11 +177,11 @@ impl IntegrationParameters { /// The CFM factor to be used in the constraint resolution. /// - /// This parameter is computed automatically from [`Self::natural_frequency`], - /// [`Self::damping_ratio`] and the substep length. - pub fn cfm_factor(&self) -> Real { + /// This parameter is computed automatically from [`Self::contact_natural_frequency`], + /// [`Self::contact_damping_ratio`] and the substep length. + pub fn contact_cfm_factor(&self) -> Real { // Compute CFM assuming a critically damped spring multiplied by the damping ratio. - let inv_erp_minus_one = 1.0 / self.erp() - 1.0; + let inv_erp_minus_one = 1.0 / self.contact_erp() - 1.0; // let stiffness = 4.0 * damping_ratio * damping_ratio * projected_mass // / (dt * dt * inv_erp_minus_one * inv_erp_minus_one); diff --git a/src/dynamics/solver/contact_constraint/one_body_constraint.rs b/src/dynamics/solver/contact_constraint/one_body_constraint.rs index 1998659..5e6e86b 100644 --- a/src/dynamics/solver/contact_constraint/one_body_constraint.rs +++ b/src/dynamics/solver/contact_constraint/one_body_constraint.rs @@ -272,9 +272,9 @@ impl OneBodyConstraintBuilder { rb2_pos: &Isometry<Real>, constraint: &mut OneBodyConstraint, ) { - let cfm_factor = params.cfm_factor(); + let cfm_factor = params.contact_cfm_factor(); let inv_dt = params.inv_dt(); - let erp_inv_dt = params.erp_inv_dt(); + let erp_inv_dt = params.contact_erp_inv_dt(); let all_infos = &self.infos[..constraint.num_contacts as usize]; let all_elements = &mut constraint.elements[..constraint.num_contacts as usize]; diff --git a/src/dynamics/solver/contact_constraint/one_body_constraint_simd.rs b/src/dynamics/solver/contact_constraint/one_body_constraint_simd.rs index 1e470b0..077dd75 100644 --- a/src/dynamics/solver/contact_constraint/one_body_constraint_simd.rs +++ b/src/dynamics/solver/contact_constraint/one_body_constraint_simd.rs @@ -261,10 +261,10 @@ impl SimdOneBodyConstraintBuilder { _multibodies: &MultibodyJointSet, constraint: &mut OneBodyConstraintSimd, ) { - let cfm_factor = SimdReal::splat(params.cfm_factor()); + let cfm_factor = SimdReal::splat(params.contact_cfm_factor()); let inv_dt = SimdReal::splat(params.inv_dt()); let allowed_lin_err = SimdReal::splat(params.allowed_linear_error()); - let erp_inv_dt = SimdReal::splat(params.erp_inv_dt()); + let erp_inv_dt = SimdReal::splat(params.contact_erp_inv_dt()); let max_corrective_velocity = SimdReal::splat(params.max_corrective_velocity()); let warmstart_coeff = SimdReal::splat(params.warmstart_coefficient); diff --git a/src/dynamics/solver/contact_constraint/two_body_constraint.rs b/src/dynamics/solver/contact_constraint/two_body_constraint.rs index cb13664..d2a2c49 100644 --- a/src/dynamics/solver/contact_constraint/two_body_constraint.rs +++ b/src/dynamics/solver/contact_constraint/two_body_constraint.rs @@ -373,9 +373,9 @@ impl TwoBodyConstraintBuilder { rb2_pos: &Isometry<Real>, constraint: &mut TwoBodyConstraint, ) { - let cfm_factor = params.cfm_factor(); + let cfm_factor = params.contact_cfm_factor(); let inv_dt = params.inv_dt(); - let erp_inv_dt = params.erp_inv_dt(); + let erp_inv_dt = params.contact_erp_inv_dt(); let all_infos = &self.infos[..constraint.num_contacts as usize]; let all_elements = &mut constraint.elements[..constraint.num_contacts as usize]; diff --git a/src/dynamics/solver/contact_constraint/two_body_constraint_simd.rs b/src/dynamics/solver/contact_constraint/two_body_constraint_simd.rs index 33e5558..2e2c68a 100644 --- a/src/dynamics/solver/contact_constraint/two_body_constraint_simd.rs +++ b/src/dynamics/solver/contact_constraint/two_body_constraint_simd.rs @@ -250,10 +250,10 @@ impl TwoBodyConstraintBuilderSimd { _multibodies: &MultibodyJointSet, constraint: &mut TwoBodyConstraintSimd, ) { - let cfm_factor = SimdReal::splat(params.cfm_factor()); + let cfm_factor = SimdReal::splat(params.contact_cfm_factor()); let inv_dt = SimdReal::splat(params.inv_dt()); let allowed_lin_err = SimdReal::splat(params.allowed_linear_error()); - let erp_inv_dt = SimdReal::splat(params.erp_inv_dt()); + let erp_inv_dt = SimdReal::splat(params.contact_erp_inv_dt()); let max_corrective_velocity = SimdReal::splat(params.max_corrective_velocity()); let warmstart_coeff = SimdReal::splat(params.warmstart_coefficient); |