Files
rapier/src/dynamics/solver/joint_constraint/generic_velocity_constraint.rs
2021-02-11 18:52:07 +01:00

685 lines
24 KiB
Rust

use crate::dynamics::solver::DeltaVel;
use crate::dynamics::{
GenericJoint, IntegrationParameters, JointGraphEdge, JointIndex, JointParams, RigidBody,
};
use crate::math::{AngularInertia, Dim, Isometry, Real, SpacialVector, Vector, DIM};
use crate::parry::math::{AngDim, SpatialVector};
use crate::utils::{WAngularInertia, WCross, WCrossMatrix};
#[cfg(feature = "dim2")]
use na::{Matrix3, Vector3};
#[cfg(feature = "dim3")]
use na::{Matrix6, Vector6, U3};
#[derive(Debug)]
pub(crate) struct GenericVelocityConstraint {
mj_lambda1: usize,
mj_lambda2: usize,
joint_id: JointIndex,
impulse: SpacialVector<Real>,
pos_impulse: SpacialVector<Real>,
max_positive_impulse: SpatialVector<Real>,
max_negative_impulse: SpatialVector<Real>,
#[cfg(feature = "dim3")]
inv_lhs: Matrix6<Real>, // FIXME: replace by Cholesky.
#[cfg(feature = "dim3")]
rhs: Vector6<Real>,
#[cfg(feature = "dim2")]
inv_lhs: Matrix3<Real>, // FIXME: replace by Cholesky.
#[cfg(feature = "dim2")]
rhs: Vector3<Real>,
pos_rhs: Vector6<Real>,
im1: Real,
im2: Real,
ii1: AngularInertia<Real>,
ii2: AngularInertia<Real>,
ii1_sqrt: AngularInertia<Real>,
ii2_sqrt: AngularInertia<Real>,
r1: Vector<Real>,
r2: Vector<Real>,
}
impl GenericVelocityConstraint {
#[inline(always)]
pub fn compute_mass_matrix(
joint: &GenericJoint,
im1: Real,
im2: Real,
ii1: AngularInertia<Real>,
ii2: AngularInertia<Real>,
r1: Vector<Real>,
r2: Vector<Real>,
velocity_solver: bool,
) -> Matrix6<Real> {
let rmat1 = r1.gcross_matrix();
let rmat2 = r2.gcross_matrix();
#[allow(unused_mut)] // For 2D
let mut lhs;
#[cfg(feature = "dim3")]
{
let lhs00 =
ii1.quadform(&rmat1).add_diagonal(im1) + ii2.quadform(&rmat2).add_diagonal(im2);
let lhs10 = ii1.transform_matrix(&rmat1) + ii2.transform_matrix(&rmat2);
let lhs11 = (ii1 + ii2).into_matrix();
// Note that Cholesky only reads the lower-triangular part of the matrix
// so we don't need to fill lhs01.
lhs = Matrix6::zeros();
lhs.fixed_slice_mut::<U3, U3>(0, 0)
.copy_from(&lhs00.into_matrix());
lhs.fixed_slice_mut::<U3, U3>(3, 0).copy_from(&lhs10);
lhs.fixed_slice_mut::<U3, U3>(3, 3).copy_from(&lhs11);
// Adjust the mass matrix to take force limits into account.
// If a DoF has a force limit, then we need to make its
// constraint independent from the others because otherwise
// the force clamping will cause errors to propagate in the
// other constraints.
if velocity_solver {
for i in 0..6 {
if joint.max_negative_impulse[i] > -Real::MAX
|| joint.max_positive_impulse[i] < Real::MAX
{
let diag = lhs[(i, i)];
lhs.column_mut(i).fill(0.0);
lhs.row_mut(i).fill(0.0);
lhs[(i, i)] = diag;
}
}
}
}
// In 2D we just unroll the computation because
// it's just easier that way.
#[cfg(feature = "dim2")]
{
let m11 = im1 + im2 + rmat1.x * rmat1.x * ii1 + rmat2.x * rmat2.x * ii2;
let m12 = rmat1.x * rmat1.y * ii1 + rmat2.x * rmat2.y * ii2;
let m22 = im1 + im2 + rmat1.y * rmat1.y * ii1 + rmat2.y * rmat2.y * ii2;
let m13 = rmat1.x * ii1 + rmat2.x * ii2;
let m23 = rmat1.y * ii1 + rmat2.y * ii2;
let m33 = ii1 + ii2;
lhs = Matrix3::new(m11, m12, m13, m12, m22, m23, m13, m23, m33)
}
// NOTE: we don't use Cholesky in 2D because we only have a 3x3 matrix
// for which a textbook inverse is still efficient.
#[cfg(feature = "dim2")]
return lhs.try_inverse().expect("Singular system.");
#[cfg(feature = "dim3")]
return lhs.cholesky().expect("Singular system.").inverse();
}
pub fn from_params(
params: &IntegrationParameters,
joint_id: JointIndex,
rb1: &RigidBody,
rb2: &RigidBody,
joint: &GenericJoint,
) -> Self {
let anchor1 = rb1.position * joint.local_anchor1;
let anchor2 = rb2.position * joint.local_anchor2;
let im1 = rb1.effective_inv_mass;
let im2 = rb2.effective_inv_mass;
let ii1 = rb1.effective_world_inv_inertia_sqrt.squared();
let ii2 = rb2.effective_world_inv_inertia_sqrt.squared();
let r1 = anchor1.translation.vector - rb1.world_com.coords;
let r2 = anchor2.translation.vector - rb2.world_com.coords;
let lin_dvel = -rb1.linvel - rb1.angvel.gcross(r1) + rb2.linvel + rb2.angvel.gcross(r2);
let ang_dvel = -rb1.angvel + rb2.angvel;
let inv_lhs = Self::compute_mass_matrix(joint, im1, im2, ii1, ii2, r1, r2, true);
#[cfg(feature = "dim2")]
let dvel = Vector3::new(lin_dvel.x, lin_dvel.y, ang_dvel);
#[cfg(feature = "dim3")]
let dvel = Vector6::new(
lin_dvel.x, lin_dvel.y, lin_dvel.z, ang_dvel.x, ang_dvel.y, ang_dvel.z,
);
let target_linvel = anchor2 * joint.target_velocity.xyz();
let target_angvel = anchor2 * joint.target_velocity.fixed_rows::<AngDim>(DIM).into_owned();
let target_vel = Vector6::new(
target_linvel.x,
target_linvel.y,
target_linvel.z,
target_angvel.x,
target_angvel.y,
target_angvel.z,
);
let rhs = dvel - dvel.sup(&target_vel).inf(&target_vel);
let delta_pos = Isometry::from_parts(
anchor2.translation * anchor1.translation.inverse(),
anchor2.rotation * anchor1.rotation.inverse(),
);
let lin_dpos = delta_pos.translation.vector;
let ang_dpos = delta_pos.rotation.scaled_axis();
let dpos = Vector6::new(
lin_dpos.x, lin_dpos.y, lin_dpos.z, ang_dpos.x, ang_dpos.y, ang_dpos.z,
);
let err = dpos - dpos.sup(&joint.min_position).inf(&joint.max_position);
let pos_rhs = err * params.inv_dt() * params.joint_erp;
let impulse = (joint.impulse * params.warmstart_coeff)
.inf(&joint.max_positive_impulse)
.sup(&joint.max_negative_impulse);
GenericVelocityConstraint {
joint_id,
mj_lambda1: rb1.active_set_offset,
mj_lambda2: rb2.active_set_offset,
im1,
im2,
ii1,
ii2,
ii1_sqrt: rb1.effective_world_inv_inertia_sqrt,
ii2_sqrt: rb2.effective_world_inv_inertia_sqrt,
impulse,
pos_impulse: na::zero(),
max_positive_impulse: joint.max_positive_impulse,
max_negative_impulse: joint.max_negative_impulse,
inv_lhs,
r1,
r2,
rhs,
pos_rhs,
}
}
pub fn warmstart(&self, mj_lambdas: &mut [DeltaVel<Real>]) {
let mut mj_lambda1 = mj_lambdas[self.mj_lambda1 as usize];
let mut mj_lambda2 = mj_lambdas[self.mj_lambda2 as usize];
let lin_impulse = self.impulse.fixed_rows::<Dim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = self.impulse[2];
#[cfg(feature = "dim3")]
let ang_impulse = self.impulse.fixed_rows::<U3>(3).into_owned();
mj_lambda1.linear += self.im1 * lin_impulse;
mj_lambda1.angular += self
.ii1_sqrt
.transform_vector(ang_impulse + self.r1.gcross(lin_impulse));
mj_lambda2.linear -= self.im2 * lin_impulse;
mj_lambda2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
mj_lambdas[self.mj_lambda1 as usize] = mj_lambda1;
mj_lambdas[self.mj_lambda2 as usize] = mj_lambda2;
}
pub fn solve(&mut self, mj_lambdas: &mut [DeltaVel<Real>]) {
return;
let mut mj_lambda1 = mj_lambdas[self.mj_lambda1 as usize];
let mut mj_lambda2 = mj_lambdas[self.mj_lambda2 as usize];
let ang_vel1 = self.ii1_sqrt.transform_vector(mj_lambda1.angular);
let ang_vel2 = self.ii2_sqrt.transform_vector(mj_lambda2.angular);
let dlinvel = -mj_lambda1.linear - ang_vel1.gcross(self.r1)
+ mj_lambda2.linear
+ ang_vel2.gcross(self.r2);
let dangvel = -ang_vel1 + ang_vel2;
#[cfg(feature = "dim2")]
let rhs = Vector3::new(dlinvel.x, dlinvel.y, dangvel) + self.rhs;
#[cfg(feature = "dim3")]
let dvel = Vector6::new(
dlinvel.x, dlinvel.y, dlinvel.z, dangvel.x, dangvel.y, dangvel.z,
) + self.rhs;
let new_impulse = (self.impulse + self.inv_lhs * dvel)
.sup(&self.max_negative_impulse)
.inf(&self.max_positive_impulse);
let effective_impulse = new_impulse - self.impulse;
self.impulse = new_impulse;
let lin_impulse = effective_impulse.fixed_rows::<Dim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = effective_impulse[2];
#[cfg(feature = "dim3")]
let ang_impulse = effective_impulse.fixed_rows::<U3>(3).into_owned();
mj_lambda1.linear += self.im1 * lin_impulse;
mj_lambda1.angular += self
.ii1_sqrt
.transform_vector(ang_impulse + self.r1.gcross(lin_impulse));
mj_lambda2.linear -= self.im2 * lin_impulse;
mj_lambda2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
mj_lambdas[self.mj_lambda1 as usize] = mj_lambda1;
mj_lambdas[self.mj_lambda2 as usize] = mj_lambda2;
}
pub fn solve2(
&mut self,
mj_lambdas: &mut [DeltaVel<Real>],
mj_lambdas_pos: &mut [DeltaVel<Real>],
) {
let mut mj_lambda1 = mj_lambdas[self.mj_lambda1 as usize];
let mut mj_lambda2 = mj_lambdas[self.mj_lambda2 as usize];
let mut mj_lambda_pos1 = mj_lambdas_pos[self.mj_lambda1 as usize];
let mut mj_lambda_pos2 = mj_lambdas_pos[self.mj_lambda2 as usize];
/*
* Solve velocity.
*/
let ang_vel1 = self.ii1_sqrt.transform_vector(mj_lambda1.angular);
let ang_vel2 = self.ii2_sqrt.transform_vector(mj_lambda2.angular);
let dlinvel = -mj_lambda1.linear - ang_vel1.gcross(self.r1)
+ mj_lambda2.linear
+ ang_vel2.gcross(self.r2);
let dangvel = -ang_vel1 + ang_vel2;
#[cfg(feature = "dim2")]
let rhs = Vector3::new(dlinvel.x, dlinvel.y, dangvel) + self.rhs;
#[cfg(feature = "dim3")]
let dvel = Vector6::new(
dlinvel.x, dlinvel.y, dlinvel.z, dangvel.x, dangvel.y, dangvel.z,
) + self.rhs;
let new_impulse = (self.impulse + self.inv_lhs * dvel)
.sup(&self.max_negative_impulse)
.inf(&self.max_positive_impulse);
let effective_impulse = new_impulse - self.impulse;
self.impulse = new_impulse;
let lin_impulse = effective_impulse.fixed_rows::<Dim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = effective_impulse[2];
#[cfg(feature = "dim3")]
let ang_impulse = effective_impulse.fixed_rows::<U3>(3).into_owned();
mj_lambda1.linear += self.im1 * lin_impulse;
mj_lambda1.angular += self
.ii1_sqrt
.transform_vector(ang_impulse + self.r1.gcross(lin_impulse));
mj_lambda2.linear -= self.im2 * lin_impulse;
mj_lambda2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
/*
* Solve positions.
*/
let ang_pos1 = self.ii1_sqrt.transform_vector(mj_lambda_pos1.angular);
let ang_pos2 = self.ii2_sqrt.transform_vector(mj_lambda_pos2.angular);
let dlinpos = -mj_lambda_pos1.linear - ang_pos1.gcross(self.r1)
+ mj_lambda_pos2.linear
+ ang_pos2.gcross(self.r2);
let dangpos = -ang_pos1 + ang_pos2;
#[cfg(feature = "dim3")]
let dpos = Vector6::new(
dlinpos.x, dlinpos.y, dlinpos.z, dangpos.x, dangpos.y, dangpos.z,
) + self.pos_rhs;
let new_impulse = self.pos_impulse + self.inv_lhs * dpos;
let effective_impulse = new_impulse - self.pos_impulse;
self.pos_impulse = new_impulse;
let lin_impulse = effective_impulse.fixed_rows::<Dim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = effective_impulse[2];
#[cfg(feature = "dim3")]
let ang_impulse = effective_impulse.fixed_rows::<U3>(3).into_owned();
mj_lambda_pos1.linear += self.im1 * lin_impulse;
mj_lambda_pos1.angular += self
.ii1_sqrt
.transform_vector(ang_impulse + self.r1.gcross(lin_impulse));
mj_lambda_pos2.linear -= self.im2 * lin_impulse;
mj_lambda_pos2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
mj_lambdas[self.mj_lambda1 as usize] = mj_lambda1;
mj_lambdas[self.mj_lambda2 as usize] = mj_lambda2;
mj_lambdas_pos[self.mj_lambda1 as usize] = mj_lambda_pos1;
mj_lambdas_pos[self.mj_lambda2 as usize] = mj_lambda_pos2;
}
pub fn writeback_impulses(&self, joints_all: &mut [JointGraphEdge]) {
let joint = &mut joints_all[self.joint_id].weight;
if let JointParams::GenericJoint(fixed) = &mut joint.params {
fixed.impulse = self.impulse;
}
}
}
#[derive(Debug)]
pub(crate) struct GenericVelocityGroundConstraint {
mj_lambda2: usize,
joint_id: JointIndex,
impulse: SpacialVector<Real>,
pos_impulse: SpacialVector<Real>,
max_positive_impulse: SpatialVector<Real>,
max_negative_impulse: SpatialVector<Real>,
#[cfg(feature = "dim3")]
inv_lhs: Matrix6<Real>, // FIXME: replace by Cholesky.
#[cfg(feature = "dim3")]
rhs: Vector6<Real>,
#[cfg(feature = "dim2")]
inv_lhs: Matrix3<Real>, // FIXME: replace by Cholesky.
#[cfg(feature = "dim2")]
rhs: Vector3<Real>,
pos_rhs: Vector6<Real>,
im2: Real,
ii2: AngularInertia<Real>,
ii2_sqrt: AngularInertia<Real>,
r2: Vector<Real>,
}
impl GenericVelocityGroundConstraint {
#[inline(always)]
pub fn compute_mass_matrix(
joint: &GenericJoint,
im2: Real,
ii2: AngularInertia<Real>,
r2: Vector<Real>,
velocity_solver: bool,
) -> Matrix6<Real> {
let rmat2 = r2.gcross_matrix();
#[allow(unused_mut)] // For 2D.
let mut lhs;
#[cfg(feature = "dim3")]
{
let lhs00 = ii2.quadform(&rmat2).add_diagonal(im2);
let lhs10 = ii2.transform_matrix(&rmat2);
let lhs11 = ii2.into_matrix();
// Note that Cholesky only reads the lower-triangular part of the matrix
// so we don't need to fill lhs01.
lhs = Matrix6::zeros();
lhs.fixed_slice_mut::<U3, U3>(0, 0)
.copy_from(&lhs00.into_matrix());
lhs.fixed_slice_mut::<U3, U3>(3, 0).copy_from(&lhs10);
lhs.fixed_slice_mut::<U3, U3>(3, 3).copy_from(&lhs11);
// Adjust the mass matrix to take force limits into account.
// If a DoF has a force limit, then we need to make its
// constraint independent from the others because otherwise
// the force clamping will cause errors to propagate in the
// other constraints.
if velocity_solver {
for i in 0..6 {
if joint.max_negative_impulse[i] > -Real::MAX
|| joint.max_positive_impulse[i] < Real::MAX
{
let diag = lhs[(i, i)];
lhs.column_mut(i).fill(0.0);
lhs.row_mut(i).fill(0.0);
lhs[(i, i)] = diag;
}
}
}
}
// In 2D we just unroll the computation because
// it's just easier that way.
#[cfg(feature = "dim2")]
{
let m11 = im2 + rmat2.x * rmat2.x * ii2;
let m12 = rmat2.x * rmat2.y * ii2;
let m22 = im2 + rmat2.y * rmat2.y * ii2;
let m13 = rmat2.x * ii2;
let m23 = rmat2.y * ii2;
let m33 = ii2;
lhs = Matrix3::new(m11, m12, m13, m12, m22, m23, m13, m23, m33)
}
#[cfg(feature = "dim2")]
return lhs.try_inverse().expect("Singular system.");
#[cfg(feature = "dim3")]
return lhs.cholesky().expect("Singular system.").inverse();
}
pub fn from_params(
params: &IntegrationParameters,
joint_id: JointIndex,
rb1: &RigidBody,
rb2: &RigidBody,
joint: &GenericJoint,
flipped: bool,
) -> Self {
let (anchor1, anchor2) = if flipped {
(
rb1.position * joint.local_anchor2,
rb2.position * joint.local_anchor1,
)
} else {
(
rb1.position * joint.local_anchor1,
rb2.position * joint.local_anchor2,
)
};
let r1 = anchor1.translation.vector - rb1.world_com.coords;
let im2 = rb2.effective_inv_mass;
let ii2 = rb2.effective_world_inv_inertia_sqrt.squared();
let r2 = anchor2.translation.vector - rb2.world_com.coords;
let inv_lhs = Self::compute_mass_matrix(joint, im2, ii2, r2, true);
let lin_dvel = rb2.linvel + rb2.angvel.gcross(r2) - rb1.linvel - rb1.angvel.gcross(r1);
let ang_dvel = rb2.angvel - rb1.angvel;
#[cfg(feature = "dim2")]
let dvel = Vector3::new(lin_dvel.x, lin_dvel.y, ang_dvel);
#[cfg(feature = "dim3")]
let dvel = Vector6::new(
lin_dvel.x, lin_dvel.y, lin_dvel.z, ang_dvel.x, ang_dvel.y, ang_dvel.z,
);
let target_linvel = anchor2 * joint.target_velocity.xyz();
let target_angvel = anchor2 * joint.target_velocity.fixed_rows::<AngDim>(DIM).into_owned();
let target_vel = Vector6::new(
target_linvel.x,
target_linvel.y,
target_linvel.z,
target_angvel.x,
target_angvel.y,
target_angvel.z,
);
let mut rhs = dvel - dvel.sup(&target_vel).inf(&target_vel);
let delta_pos = Isometry::from_parts(
anchor2.translation * anchor1.translation.inverse(),
anchor2.rotation * anchor1.rotation.inverse(),
);
let lin_dpos = delta_pos.translation.vector;
let ang_dpos = delta_pos.rotation.scaled_axis();
let dpos = Vector6::new(
lin_dpos.x, lin_dpos.y, lin_dpos.z, ang_dpos.x, ang_dpos.y, ang_dpos.z,
);
let err = dpos - dpos.sup(&joint.min_position).inf(&joint.max_position);
let pos_rhs = err * params.inv_dt() * params.joint_erp;
let impulse = (joint.impulse * params.warmstart_coeff)
.inf(&joint.max_positive_impulse)
.sup(&joint.max_negative_impulse);
GenericVelocityGroundConstraint {
joint_id,
mj_lambda2: rb2.active_set_offset,
im2,
ii2,
ii2_sqrt: rb2.effective_world_inv_inertia_sqrt,
impulse,
pos_impulse: na::zero(),
max_positive_impulse: joint.max_positive_impulse,
max_negative_impulse: joint.max_negative_impulse,
inv_lhs,
r2,
rhs,
pos_rhs,
}
}
pub fn warmstart(&self, mj_lambdas: &mut [DeltaVel<Real>]) {
let mut mj_lambda2 = mj_lambdas[self.mj_lambda2 as usize];
let lin_impulse = self.impulse.fixed_rows::<Dim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = self.impulse[2];
#[cfg(feature = "dim3")]
let ang_impulse = self.impulse.fixed_rows::<U3>(3).into_owned();
mj_lambda2.linear -= self.im2 * lin_impulse;
mj_lambda2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
mj_lambdas[self.mj_lambda2 as usize] = mj_lambda2;
}
pub fn solve(&mut self, mj_lambdas: &mut [DeltaVel<Real>]) {
return;
let mut mj_lambda2 = mj_lambdas[self.mj_lambda2 as usize];
let ang_vel2 = self.ii2_sqrt.transform_vector(mj_lambda2.angular);
let dlinvel = mj_lambda2.linear + ang_vel2.gcross(self.r2);
let dangvel = ang_vel2;
#[cfg(feature = "dim2")]
let rhs = Vector3::new(dlinvel.x, dlinvel.y, dangvel) + self.rhs;
#[cfg(feature = "dim3")]
let dvel = Vector6::new(
dlinvel.x, dlinvel.y, dlinvel.z, dangvel.x, dangvel.y, dangvel.z,
) + self.rhs;
let new_impulse = (self.impulse + self.inv_lhs * dvel)
.sup(&self.max_negative_impulse)
.inf(&self.max_positive_impulse);
let effective_impulse = new_impulse - self.impulse;
self.impulse = new_impulse;
let lin_impulse = effective_impulse.fixed_rows::<Dim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = effective_impulse[2];
#[cfg(feature = "dim3")]
let ang_impulse = effective_impulse.fixed_rows::<U3>(3).into_owned();
mj_lambda2.linear -= self.im2 * lin_impulse;
mj_lambda2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
mj_lambdas[self.mj_lambda2 as usize] = mj_lambda2;
}
pub fn solve2(
&mut self,
mj_lambdas: &mut [DeltaVel<Real>],
mj_lambdas_pos: &mut [DeltaVel<Real>],
) {
let mut mj_lambda2 = mj_lambdas[self.mj_lambda2 as usize];
let mut mj_lambda_pos2 = mj_lambdas_pos[self.mj_lambda2 as usize];
/*
* Solve velocities.
*/
let ang_vel2 = self.ii2_sqrt.transform_vector(mj_lambda2.angular);
let dlinvel = mj_lambda2.linear + ang_vel2.gcross(self.r2);
let dangvel = ang_vel2;
#[cfg(feature = "dim2")]
let rhs = Vector3::new(dlinvel.x, dlinvel.y, dangvel) + self.rhs;
#[cfg(feature = "dim3")]
let dvel = Vector6::new(
dlinvel.x, dlinvel.y, dlinvel.z, dangvel.x, dangvel.y, dangvel.z,
) + self.rhs;
let new_impulse = (self.impulse + self.inv_lhs * dvel)
.sup(&self.max_negative_impulse)
.inf(&self.max_positive_impulse);
let effective_impulse = new_impulse - self.impulse;
self.impulse = new_impulse;
let lin_impulse = effective_impulse.fixed_rows::<Dim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = effective_impulse[2];
#[cfg(feature = "dim3")]
let ang_impulse = effective_impulse.fixed_rows::<U3>(3).into_owned();
mj_lambda2.linear -= self.im2 * lin_impulse;
mj_lambda2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
/*
* Solve positions.
*/
let ang_pos2 = self.ii2_sqrt.transform_vector(mj_lambda_pos2.angular);
let dlinpos = mj_lambda_pos2.linear + ang_pos2.gcross(self.r2);
let dangpos = ang_pos2;
#[cfg(feature = "dim2")]
let rhs = Vector3::new(dlinpos.x, dlinpos.y, dangpos) + self.rhs;
#[cfg(feature = "dim3")]
let dpos = Vector6::new(
dlinpos.x, dlinpos.y, dlinpos.z, dangpos.x, dangpos.y, dangpos.z,
) + self.pos_rhs;
let new_impulse = self.pos_impulse + self.inv_lhs * dpos;
let effective_impulse = new_impulse - self.pos_impulse;
self.pos_impulse = new_impulse;
let lin_impulse = effective_impulse.fixed_rows::<Dim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = effective_impulse[2];
#[cfg(feature = "dim3")]
let ang_impulse = effective_impulse.fixed_rows::<U3>(3).into_owned();
mj_lambda_pos2.linear -= self.im2 * lin_impulse;
mj_lambda_pos2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
mj_lambdas[self.mj_lambda2 as usize] = mj_lambda2;
mj_lambdas_pos[self.mj_lambda2 as usize] = mj_lambda_pos2;
}
// FIXME: duplicated code with the non-ground constraint.
pub fn writeback_impulses(&self, joints_all: &mut [JointGraphEdge]) {
let joint = &mut joints_all[self.joint_id].weight;
if let JointParams::GenericJoint(fixed) = &mut joint.params {
fixed.impulse = self.impulse;
}
}
}