Files
rapier/src/dynamics/solver/joint_constraint/prismatic_velocity_constraint_wide.rs
2021-02-26 11:06:29 +01:00

816 lines
32 KiB
Rust

use simba::simd::{SimdBool as _, SimdPartialOrd, SimdValue};
use crate::dynamics::solver::DeltaVel;
use crate::dynamics::{
IntegrationParameters, JointGraphEdge, JointIndex, JointParams, PrismaticJoint, RigidBody,
};
use crate::math::{
AngVector, AngularInertia, Isometry, Point, Real, SimdBool, SimdReal, Vector, SIMD_WIDTH,
};
use crate::utils::{WAngularInertia, WCross, WCrossMatrix, WDot};
#[cfg(feature = "dim3")]
use na::{Cholesky, Matrix3x2, Matrix5, Vector3, Vector5, U2, U3};
#[cfg(feature = "dim2")]
use {
na::{Matrix2, Vector2},
parry::utils::SdpMatrix2,
};
#[cfg(feature = "dim2")]
type LinImpulseDim = na::U1;
#[cfg(feature = "dim3")]
type LinImpulseDim = na::U2;
#[derive(Debug)]
pub(crate) struct WPrismaticVelocityConstraint {
mj_lambda1: [usize; SIMD_WIDTH],
mj_lambda2: [usize; SIMD_WIDTH],
joint_id: [JointIndex; SIMD_WIDTH],
r1: Vector<SimdReal>,
r2: Vector<SimdReal>,
#[cfg(feature = "dim3")]
inv_lhs: Matrix5<SimdReal>,
#[cfg(feature = "dim3")]
rhs: Vector5<SimdReal>,
#[cfg(feature = "dim3")]
impulse: Vector5<SimdReal>,
#[cfg(feature = "dim2")]
inv_lhs: Matrix2<SimdReal>,
#[cfg(feature = "dim2")]
rhs: Vector2<SimdReal>,
#[cfg(feature = "dim2")]
impulse: Vector2<SimdReal>,
limits_impulse: SimdReal,
limits_forcedirs: Option<(Vector<SimdReal>, Vector<SimdReal>)>,
limits_rhs: SimdReal,
limits_inv_lhs: SimdReal,
#[cfg(feature = "dim2")]
basis1: Vector2<SimdReal>,
#[cfg(feature = "dim3")]
basis1: Matrix3x2<SimdReal>,
im1: SimdReal,
im2: SimdReal,
ii1_sqrt: AngularInertia<SimdReal>,
ii2_sqrt: AngularInertia<SimdReal>,
}
impl WPrismaticVelocityConstraint {
pub fn from_params(
params: &IntegrationParameters,
joint_id: [JointIndex; SIMD_WIDTH],
rbs1: [&RigidBody; SIMD_WIDTH],
rbs2: [&RigidBody; SIMD_WIDTH],
cparams: [&PrismaticJoint; SIMD_WIDTH],
) -> Self {
let position1 = Isometry::from(array![|ii| rbs1[ii].position; SIMD_WIDTH]);
let linvel1 = Vector::from(array![|ii| rbs1[ii].linvel; SIMD_WIDTH]);
let angvel1 = AngVector::<SimdReal>::from(array![|ii| rbs1[ii].angvel; SIMD_WIDTH]);
let world_com1 = Point::from(array![|ii| rbs1[ii].world_com; SIMD_WIDTH]);
let im1 = SimdReal::from(array![|ii| rbs1[ii].effective_inv_mass; SIMD_WIDTH]);
let ii1_sqrt = AngularInertia::<SimdReal>::from(
array![|ii| rbs1[ii].effective_world_inv_inertia_sqrt; SIMD_WIDTH],
);
let mj_lambda1 = array![|ii| rbs1[ii].active_set_offset; SIMD_WIDTH];
let position2 = Isometry::from(array![|ii| rbs2[ii].position; SIMD_WIDTH]);
let linvel2 = Vector::from(array![|ii| rbs2[ii].linvel; SIMD_WIDTH]);
let angvel2 = AngVector::<SimdReal>::from(array![|ii| rbs2[ii].angvel; SIMD_WIDTH]);
let world_com2 = Point::from(array![|ii| rbs2[ii].world_com; SIMD_WIDTH]);
let im2 = SimdReal::from(array![|ii| rbs2[ii].effective_inv_mass; SIMD_WIDTH]);
let ii2_sqrt = AngularInertia::<SimdReal>::from(
array![|ii| rbs2[ii].effective_world_inv_inertia_sqrt; SIMD_WIDTH],
);
let mj_lambda2 = array![|ii| rbs2[ii].active_set_offset; SIMD_WIDTH];
let local_anchor1 = Point::from(array![|ii| cparams[ii].local_anchor1; SIMD_WIDTH]);
let local_anchor2 = Point::from(array![|ii| cparams[ii].local_anchor2; SIMD_WIDTH]);
let local_axis1 = Vector::from(array![|ii| *cparams[ii].local_axis1; SIMD_WIDTH]);
let local_axis2 = Vector::from(array![|ii| *cparams[ii].local_axis2; SIMD_WIDTH]);
#[cfg(feature = "dim2")]
let local_basis1 = [Vector::from(array![|ii| cparams[ii].basis1[0]; SIMD_WIDTH])];
#[cfg(feature = "dim3")]
let local_basis1 = [
Vector::from(array![|ii| cparams[ii].basis1[0]; SIMD_WIDTH]),
Vector::from(array![|ii| cparams[ii].basis1[1]; SIMD_WIDTH]),
];
#[cfg(feature = "dim2")]
let impulse = Vector2::from(array![|ii| cparams[ii].impulse; SIMD_WIDTH]);
#[cfg(feature = "dim3")]
let impulse = Vector5::from(array![|ii| cparams[ii].impulse; SIMD_WIDTH]);
let anchor1 = position1 * local_anchor1;
let anchor2 = position2 * local_anchor2;
let axis1 = position1 * local_axis1;
let axis2 = position2 * local_axis2;
#[cfg(feature = "dim2")]
let basis1 = position1 * local_basis1[0];
#[cfg(feature = "dim3")]
let basis1 =
Matrix3x2::from_columns(&[position1 * local_basis1[0], position1 * local_basis1[1]]);
// #[cfg(feature = "dim2")]
// let r21 = Rotation::rotation_between_axis(&axis1, &axis2)
// .to_rotation_matrix()
// .into_inner();
// #[cfg(feature = "dim3")]
// let r21 = Rotation::rotation_between_axis(&axis1, &axis2)
// .unwrap_or_else(Rotation::identity)
// .to_rotation_matrix()
// .into_inner();
// let basis2 = r21 * basis1;
// NOTE: we use basis2 := basis1 for now is that allows
// simplifications of the computation without introducing
// much instabilities.
let ii1 = ii1_sqrt.squared();
let r1 = anchor1 - world_com1;
let r1_mat = r1.gcross_matrix();
let ii2 = ii2_sqrt.squared();
let r2 = anchor2 - world_com2;
let r2_mat = r2.gcross_matrix();
#[allow(unused_mut)] // For 2D.
let mut lhs;
#[cfg(feature = "dim3")]
{
let r1_mat_b1 = r1_mat * basis1;
let r2_mat_b1 = r2_mat * basis1;
lhs = Matrix5::zeros();
let lhs00 = ii1.quadform3x2(&r1_mat_b1).add_diagonal(im1)
+ ii2.quadform3x2(&r2_mat_b1).add_diagonal(im2);
let lhs10 = ii1 * r1_mat_b1 + ii2 * r2_mat_b1;
let lhs11 = (ii1 + ii2).into_matrix();
lhs.fixed_slice_mut::<U2, U2>(0, 0)
.copy_from(&lhs00.into_matrix());
lhs.fixed_slice_mut::<U3, U2>(2, 0).copy_from(&lhs10);
lhs.fixed_slice_mut::<U3, U3>(2, 2).copy_from(&lhs11);
}
#[cfg(feature = "dim2")]
{
let b1r1 = basis1.dot(&r1_mat);
let b2r2 = basis1.dot(&r2_mat);
let m11 = im1 + im2 + b1r1 * ii1 * b1r1 + b2r2 * ii2 * b2r2;
let m12 = basis1.dot(&r1_mat) * ii1 + basis1.dot(&r2_mat) * ii2;
let m22 = ii1 + ii2;
lhs = SdpMatrix2::new(m11, m12, m22);
}
let anchor_linvel1 = linvel1 + angvel1.gcross(r1);
let anchor_linvel2 = linvel2 + angvel2.gcross(r2);
// NOTE: we don't use Cholesky in 2D because we only have a 2x2 matrix
// for which a textbook inverse is still efficient.
#[cfg(feature = "dim2")]
let inv_lhs = lhs.inverse_unchecked().into_matrix();
#[cfg(feature = "dim3")]
let inv_lhs = Cholesky::new_unchecked(lhs).inverse();
let linvel_err = basis1.tr_mul(&(anchor_linvel2 - anchor_linvel1));
let angvel_err = angvel2 - angvel1;
let velocity_solve_fraction = SimdReal::splat(params.velocity_solve_fraction);
#[cfg(feature = "dim2")]
let mut rhs = Vector2::new(linvel_err.x, angvel_err) * velocity_solve_fraction;
#[cfg(feature = "dim3")]
let mut rhs = Vector5::new(
linvel_err.x,
linvel_err.y,
angvel_err.x,
angvel_err.y,
angvel_err.z,
) * velocity_solve_fraction;
let limits_enabled =
SimdBool::from(array![|ii| cparams[ii].limits_enabled; SIMD_WIDTH]).any();
let velocity_based_erp_inv_dt = params.velocity_based_erp_inv_dt();
if velocity_based_erp_inv_dt != 0.0 {
let velocity_based_erp_inv_dt = SimdReal::splat(velocity_based_erp_inv_dt);
let dpos = anchor2 - anchor1;
let limit_err = dpos.dot(&axis1);
let mut linear_err = dpos - axis1 * limit_err;
let local_frame1 = Isometry::from(array![|ii| cparams[ii].local_frame1(); SIMD_WIDTH]);
let local_frame2 = Isometry::from(array![|ii| cparams[ii].local_frame2(); SIMD_WIDTH]);
let frame1 = position1 * local_frame1;
let frame2 = position2 * local_frame2;
let ang_err = frame2.rotation * frame1.rotation.inverse();
if limits_enabled {
let min_limit = SimdReal::from(array![|ii| cparams[ii].limits[0]; SIMD_WIDTH]);
let max_limit = SimdReal::from(array![|ii| cparams[ii].limits[1]; SIMD_WIDTH]);
let zero: SimdReal = na::zero();
linear_err += axis1
* ((limit_err - max_limit).simd_max(zero)
- (min_limit - limit_err).simd_max(zero));
}
#[cfg(feature = "dim2")]
{
rhs += Vector2::new(linear_err.x, ang_err.angle()) * velocity_based_erp_inv_dt;
}
#[cfg(feature = "dim3")]
{
let ang_err =
Vector3::from(array![|ii| ang_err.extract(ii).scaled_axis(); SIMD_WIDTH]);
rhs += Vector5::new(linear_err.x, linear_err.y, ang_err.x, ang_err.y, ang_err.z)
* velocity_based_erp_inv_dt;
}
}
/*
* Setup limit constraint.
*/
let mut limits_forcedirs = None;
let mut limits_rhs = na::zero();
let mut limits_impulse = na::zero();
let mut limits_inv_lhs = na::zero();
let limits_enabled = SimdBool::from(array![|ii| cparams[ii].limits_enabled; SIMD_WIDTH]);
if limits_enabled {
let danchor = anchor2 - anchor1;
let dist = danchor.dot(&axis1);
// FIXME: we should allow both limits to be active at
// the same time + allow predictive constraint activation.
let min_limit = SimdReal::from(array![|ii| cparams[ii].limits[0]; SIMD_WIDTH]);
let max_limit = SimdReal::from(array![|ii| cparams[ii].limits[1]; SIMD_WIDTH]);
let lim_impulse = SimdReal::from(array![|ii| cparams[ii].limits_impulse; SIMD_WIDTH]);
let min_enabled = dist.simd_lt(min_limit);
let max_enabled = dist.simd_gt(max_limit);
let _0: SimdReal = na::zero();
let _1: SimdReal = na::one();
let sign = _1.select(min_enabled, (-_1).select(max_enabled, _0));
if sign != _0 {
let gcross1 = r1.gcross(axis1);
let gcross2 = r2.gcross(axis2);
limits_forcedirs = Some((axis1 * -sign, axis2 * sign));
limits_rhs = (anchor_linvel2.dot(&axis2) - anchor_linvel1.dot(&axis1)) * sign;
limits_impulse = lim_impulse.select(min_enabled | max_enabled, _0);
limits_inv_lhs = SimdReal::splat(1.0)
/ (im1
+ im2
+ gcross1.gdot(ii1.transform_vector(gcross1))
+ gcross2.gdot(ii2.transform_vector(gcross2)));
}
}
WPrismaticVelocityConstraint {
joint_id,
mj_lambda1,
mj_lambda2,
im1,
ii1_sqrt,
im2,
ii2_sqrt,
impulse: impulse * SimdReal::splat(params.warmstart_coeff),
limits_impulse: limits_impulse * SimdReal::splat(params.warmstart_coeff),
limits_forcedirs,
limits_rhs,
limits_inv_lhs,
basis1,
inv_lhs,
rhs,
r1,
r2,
}
}
pub fn warmstart(&self, mj_lambdas: &mut [DeltaVel<Real>]) {
let mut mj_lambda1 = DeltaVel {
linear: Vector::from(
array![|ii| mj_lambdas[self.mj_lambda1[ii] as usize].linear; SIMD_WIDTH],
),
angular: AngVector::from(
array![|ii| mj_lambdas[self.mj_lambda1[ii] as usize].angular; SIMD_WIDTH],
),
};
let mut mj_lambda2 = DeltaVel {
linear: Vector::from(
array![|ii| mj_lambdas[self.mj_lambda2[ii] as usize].linear; SIMD_WIDTH],
),
angular: AngVector::from(
array![|ii| mj_lambdas[self.mj_lambda2[ii] as usize].angular; SIMD_WIDTH],
),
};
let lin_impulse = self.basis1 * self.impulse.fixed_rows::<LinImpulseDim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = self.impulse.y;
#[cfg(feature = "dim3")]
let ang_impulse = self.impulse.fixed_rows::<U3>(2).into_owned();
mj_lambda1.linear += lin_impulse * self.im1;
mj_lambda1.angular += self
.ii1_sqrt
.transform_vector(ang_impulse + self.r1.gcross(lin_impulse));
mj_lambda2.linear -= lin_impulse * self.im2;
mj_lambda2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
// Warmstart limits.
if let Some((limits_forcedir1, limits_forcedir2)) = self.limits_forcedirs {
let limit_impulse1 = limits_forcedir1 * self.limits_impulse;
let limit_impulse2 = limits_forcedir2 * self.limits_impulse;
mj_lambda1.linear += limit_impulse1 * self.im1;
mj_lambda1.angular += self
.ii1_sqrt
.transform_vector(self.r1.gcross(limit_impulse1));
mj_lambda2.linear += limit_impulse2 * self.im2;
mj_lambda2.angular += self
.ii2_sqrt
.transform_vector(self.r2.gcross(limit_impulse2));
}
for ii in 0..SIMD_WIDTH {
mj_lambdas[self.mj_lambda1[ii] as usize].linear = mj_lambda1.linear.extract(ii);
mj_lambdas[self.mj_lambda1[ii] as usize].angular = mj_lambda1.angular.extract(ii);
}
for ii in 0..SIMD_WIDTH {
mj_lambdas[self.mj_lambda2[ii] as usize].linear = mj_lambda2.linear.extract(ii);
mj_lambdas[self.mj_lambda2[ii] as usize].angular = mj_lambda2.angular.extract(ii);
}
}
fn solve_dofs(
&mut self,
mj_lambda1: &mut DeltaVel<SimdReal>,
mj_lambda2: &mut DeltaVel<SimdReal>,
) {
let ang_vel1 = self.ii1_sqrt.transform_vector(mj_lambda1.angular);
let ang_vel2 = self.ii2_sqrt.transform_vector(mj_lambda2.angular);
let lin_vel1 = mj_lambda1.linear + ang_vel1.gcross(self.r1);
let lin_vel2 = mj_lambda2.linear + ang_vel2.gcross(self.r2);
let lin_dvel = self.basis1.tr_mul(&(lin_vel2 - lin_vel1));
let ang_dvel = ang_vel2 - ang_vel1;
#[cfg(feature = "dim2")]
let rhs = Vector2::new(lin_dvel.x, ang_dvel) + self.rhs;
#[cfg(feature = "dim3")]
let rhs =
Vector5::new(lin_dvel.x, lin_dvel.y, ang_dvel.x, ang_dvel.y, ang_dvel.z) + self.rhs;
let impulse = self.inv_lhs * rhs;
self.impulse += impulse;
let lin_impulse = self.basis1 * impulse.fixed_rows::<LinImpulseDim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = impulse.y;
#[cfg(feature = "dim3")]
let ang_impulse = impulse.fixed_rows::<U3>(2).into_owned();
mj_lambda1.linear += lin_impulse * self.im1;
mj_lambda1.angular += self
.ii1_sqrt
.transform_vector(ang_impulse + self.r1.gcross(lin_impulse));
mj_lambda2.linear -= lin_impulse * self.im2;
mj_lambda2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
}
fn solve_limits(
&mut self,
mj_lambda1: &mut DeltaVel<SimdReal>,
mj_lambda2: &mut DeltaVel<SimdReal>,
) {
if let Some((limits_forcedir1, limits_forcedir2)) = self.limits_forcedirs {
let ang_vel1 = self.ii1_sqrt.transform_vector(mj_lambda1.angular);
let ang_vel2 = self.ii2_sqrt.transform_vector(mj_lambda2.angular);
let lin_dvel = limits_forcedir2.dot(&(mj_lambda2.linear + ang_vel2.gcross(self.r2)))
+ limits_forcedir1.dot(&(mj_lambda1.linear + ang_vel1.gcross(self.r1)))
+ self.limits_rhs;
let new_impulse =
(self.limits_impulse - lin_dvel * self.limits_inv_lhs).simd_max(na::zero());
let dimpulse = new_impulse - self.limits_impulse;
self.limits_impulse = new_impulse;
let lin_impulse1 = limits_forcedir1 * dimpulse;
let lin_impulse2 = limits_forcedir2 * dimpulse;
mj_lambda1.linear += lin_impulse1 * self.im1;
mj_lambda1.angular += self.ii1_sqrt.transform_vector(self.r1.gcross(lin_impulse1));
mj_lambda2.linear += lin_impulse2 * self.im2;
mj_lambda2.angular += self.ii2_sqrt.transform_vector(self.r2.gcross(lin_impulse2));
}
}
pub fn solve(&mut self, mj_lambdas: &mut [DeltaVel<Real>]) {
let mut mj_lambda1 = DeltaVel {
linear: Vector::from(
array![|ii| mj_lambdas[self.mj_lambda1[ii] as usize].linear; SIMD_WIDTH],
),
angular: AngVector::from(
array![|ii| mj_lambdas[self.mj_lambda1[ii] as usize].angular; SIMD_WIDTH],
),
};
let mut mj_lambda2 = DeltaVel {
linear: Vector::from(
array![|ii| mj_lambdas[self.mj_lambda2[ii] as usize].linear; SIMD_WIDTH],
),
angular: AngVector::from(
array![|ii| mj_lambdas[self.mj_lambda2[ii] as usize].angular; SIMD_WIDTH],
),
};
self.solve_dofs(&mut mj_lambda1, &mut mj_lambda2);
self.solve_limits(&mut mj_lambda1, &mut mj_lambda2);
for ii in 0..SIMD_WIDTH {
mj_lambdas[self.mj_lambda1[ii] as usize].linear = mj_lambda1.linear.extract(ii);
mj_lambdas[self.mj_lambda1[ii] as usize].angular = mj_lambda1.angular.extract(ii);
}
for ii in 0..SIMD_WIDTH {
mj_lambdas[self.mj_lambda2[ii] as usize].linear = mj_lambda2.linear.extract(ii);
mj_lambdas[self.mj_lambda2[ii] as usize].angular = mj_lambda2.angular.extract(ii);
}
}
pub fn writeback_impulses(&self, joints_all: &mut [JointGraphEdge]) {
for ii in 0..SIMD_WIDTH {
let joint = &mut joints_all[self.joint_id[ii]].weight;
if let JointParams::PrismaticJoint(rev) = &mut joint.params {
rev.impulse = self.impulse.extract(ii);
rev.limits_impulse = self.limits_impulse.extract(ii);
}
}
}
}
#[derive(Debug)]
pub(crate) struct WPrismaticVelocityGroundConstraint {
mj_lambda2: [usize; SIMD_WIDTH],
joint_id: [JointIndex; SIMD_WIDTH],
r2: Vector<SimdReal>,
#[cfg(feature = "dim2")]
inv_lhs: Matrix2<SimdReal>,
#[cfg(feature = "dim2")]
rhs: Vector2<SimdReal>,
#[cfg(feature = "dim2")]
impulse: Vector2<SimdReal>,
#[cfg(feature = "dim3")]
inv_lhs: Matrix5<SimdReal>,
#[cfg(feature = "dim3")]
rhs: Vector5<SimdReal>,
#[cfg(feature = "dim3")]
impulse: Vector5<SimdReal>,
limits_impulse: SimdReal,
limits_rhs: SimdReal,
axis2: Vector<SimdReal>,
#[cfg(feature = "dim2")]
basis1: Vector2<SimdReal>,
#[cfg(feature = "dim3")]
basis1: Matrix3x2<SimdReal>,
limits_forcedir2: Option<Vector<SimdReal>>,
im2: SimdReal,
ii2_sqrt: AngularInertia<SimdReal>,
}
impl WPrismaticVelocityGroundConstraint {
pub fn from_params(
params: &IntegrationParameters,
joint_id: [JointIndex; SIMD_WIDTH],
rbs1: [&RigidBody; SIMD_WIDTH],
rbs2: [&RigidBody; SIMD_WIDTH],
cparams: [&PrismaticJoint; SIMD_WIDTH],
flipped: [bool; SIMD_WIDTH],
) -> Self {
let position1 = Isometry::from(array![|ii| rbs1[ii].position; SIMD_WIDTH]);
let linvel1 = Vector::from(array![|ii| rbs1[ii].linvel; SIMD_WIDTH]);
let angvel1 = AngVector::<SimdReal>::from(array![|ii| rbs1[ii].angvel; SIMD_WIDTH]);
let world_com1 = Point::from(array![|ii| rbs1[ii].world_com; SIMD_WIDTH]);
let position2 = Isometry::from(array![|ii| rbs2[ii].position; SIMD_WIDTH]);
let linvel2 = Vector::from(array![|ii| rbs2[ii].linvel; SIMD_WIDTH]);
let angvel2 = AngVector::<SimdReal>::from(array![|ii| rbs2[ii].angvel; SIMD_WIDTH]);
let world_com2 = Point::from(array![|ii| rbs2[ii].world_com; SIMD_WIDTH]);
let im2 = SimdReal::from(array![|ii| rbs2[ii].effective_inv_mass; SIMD_WIDTH]);
let ii2_sqrt = AngularInertia::<SimdReal>::from(
array![|ii| rbs2[ii].effective_world_inv_inertia_sqrt; SIMD_WIDTH],
);
let mj_lambda2 = array![|ii| rbs2[ii].active_set_offset; SIMD_WIDTH];
#[cfg(feature = "dim2")]
let impulse = Vector2::from(array![|ii| cparams[ii].impulse; SIMD_WIDTH]);
#[cfg(feature = "dim3")]
let impulse = Vector5::from(array![|ii| cparams[ii].impulse; SIMD_WIDTH]);
let local_anchor1 = Point::from(
array![|ii| if flipped[ii] { cparams[ii].local_anchor2 } else { cparams[ii].local_anchor1 }; SIMD_WIDTH],
);
let local_anchor2 = Point::from(
array![|ii| if flipped[ii] { cparams[ii].local_anchor1 } else { cparams[ii].local_anchor2 }; SIMD_WIDTH],
);
let local_axis1 = Vector::from(
array![|ii| if flipped[ii] { *cparams[ii].local_axis2 } else { *cparams[ii].local_axis1 }; SIMD_WIDTH],
);
let local_axis2 = Vector::from(
array![|ii| if flipped[ii] { *cparams[ii].local_axis1 } else { *cparams[ii].local_axis2 }; SIMD_WIDTH],
);
#[cfg(feature = "dim2")]
let basis1 = position1
* Vector::from(
array![|ii| if flipped[ii] { cparams[ii].basis2[0] } else { cparams[ii].basis1[0] }; SIMD_WIDTH],
);
#[cfg(feature = "dim3")]
let basis1 = Matrix3x2::from_columns(&[
position1
* Vector::from(
array![|ii| if flipped[ii] { cparams[ii].basis2[0] } else { cparams[ii].basis1[0] }; SIMD_WIDTH],
),
position1
* Vector::from(
array![|ii| if flipped[ii] { cparams[ii].basis2[1] } else { cparams[ii].basis1[1] }; SIMD_WIDTH],
),
]);
let anchor1 = position1 * local_anchor1;
let anchor2 = position2 * local_anchor2;
let axis1 = position1 * local_axis1;
let axis2 = position2 * local_axis2;
let ii2 = ii2_sqrt.squared();
let r1 = anchor1 - world_com1;
let r2 = anchor2 - world_com2;
let r2_mat = r2.gcross_matrix();
#[allow(unused_mut)] // For 2D.
let mut lhs;
#[cfg(feature = "dim3")]
{
let r2_mat_b1 = r2_mat * basis1;
lhs = Matrix5::zeros();
let lhs00 = ii2.quadform3x2(&r2_mat_b1).add_diagonal(im2);
let lhs10 = ii2 * r2_mat_b1;
let lhs11 = ii2.into_matrix();
lhs.fixed_slice_mut::<U2, U2>(0, 0)
.copy_from(&lhs00.into_matrix());
lhs.fixed_slice_mut::<U3, U2>(2, 0).copy_from(&lhs10);
lhs.fixed_slice_mut::<U3, U3>(2, 2).copy_from(&lhs11);
}
#[cfg(feature = "dim2")]
{
let b2r2 = basis1.dot(&r2_mat);
let m11 = im2 + b2r2 * ii2 * b2r2;
let m12 = basis1.dot(&r2_mat) * ii2;
let m22 = ii2;
lhs = SdpMatrix2::new(m11, m12, m22);
}
let anchor_linvel1 = linvel1 + angvel1.gcross(r1);
let anchor_linvel2 = linvel2 + angvel2.gcross(r2);
// NOTE: we don't use Cholesky in 2D because we only have a 2x2 matrix
// for which a textbook inverse is still efficient.
#[cfg(feature = "dim2")]
let inv_lhs = lhs.inverse_unchecked().into_matrix();
#[cfg(feature = "dim3")]
let inv_lhs = Cholesky::new_unchecked(lhs).inverse();
let linvel_err = basis1.tr_mul(&(anchor_linvel2 - anchor_linvel1));
let angvel_err = angvel2 - angvel1;
let velocity_solve_fraction = SimdReal::splat(params.velocity_solve_fraction);
#[cfg(feature = "dim2")]
let mut rhs = Vector2::new(linvel_err.x, angvel_err) * velocity_solve_fraction;
#[cfg(feature = "dim3")]
let mut rhs = Vector5::new(
linvel_err.x,
linvel_err.y,
angvel_err.x,
angvel_err.y,
angvel_err.z,
) * velocity_solve_fraction;
let limits_enabled =
SimdBool::from(array![|ii| cparams[ii].limits_enabled; SIMD_WIDTH]).any();
let velocity_based_erp_inv_dt = params.velocity_based_erp_inv_dt();
if velocity_based_erp_inv_dt != 0.0 {
let velocity_based_erp_inv_dt = SimdReal::splat(velocity_based_erp_inv_dt);
let dpos = anchor2 - anchor1;
let limit_err = dpos.dot(&axis1);
let mut linear_err = dpos - axis1 * limit_err;
let frame1 = position1
* Isometry::from(
array![|ii| if flipped[ii] { cparams[ii].local_frame2() } else { cparams[ii].local_frame1() }; SIMD_WIDTH],
);
let frame2 = position2
* Isometry::from(
array![|ii| if flipped[ii] { cparams[ii].local_frame1() } else { cparams[ii].local_frame2() }; SIMD_WIDTH],
);
let ang_err = frame2.rotation * frame1.rotation.inverse();
if limits_enabled {
let min_limit = SimdReal::from(array![|ii| cparams[ii].limits[0]; SIMD_WIDTH]);
let max_limit = SimdReal::from(array![|ii| cparams[ii].limits[1]; SIMD_WIDTH]);
let zero: SimdReal = na::zero();
linear_err += axis1
* ((limit_err - max_limit).simd_max(zero)
- (min_limit - limit_err).simd_max(zero));
}
#[cfg(feature = "dim2")]
{
rhs += Vector2::new(linear_err.x, ang_err.angle()) * velocity_based_erp_inv_dt;
}
#[cfg(feature = "dim3")]
{
let ang_err =
Vector3::from(array![|ii| ang_err.extract(ii).scaled_axis(); SIMD_WIDTH]);
rhs += Vector5::new(linear_err.x, linear_err.y, ang_err.x, ang_err.y, ang_err.z)
* velocity_based_erp_inv_dt;
}
}
// Setup limit constraint.
let mut limits_forcedir2 = None;
let mut limits_rhs = na::zero();
let mut limits_impulse = na::zero();
if limits_enabled {
let danchor = anchor2 - anchor1;
let dist = danchor.dot(&axis1);
// FIXME: we should allow both limits to be active at
// the same time + allow predictive constraint activation.
let min_limit = SimdReal::from(array![|ii| cparams[ii].limits[0]; SIMD_WIDTH]);
let max_limit = SimdReal::from(array![|ii| cparams[ii].limits[1]; SIMD_WIDTH]);
let lim_impulse = SimdReal::from(array![|ii| cparams[ii].limits_impulse; SIMD_WIDTH]);
let use_min = dist.simd_lt(min_limit);
let use_max = dist.simd_gt(max_limit);
let _0: SimdReal = na::zero();
let _1: SimdReal = na::one();
let sign = _1.select(use_min, (-_1).select(use_max, _0));
if sign != _0 {
limits_forcedir2 = Some(axis2 * sign);
limits_rhs = anchor_linvel2.dot(&axis2) * sign - anchor_linvel1.dot(&axis1) * sign;
limits_impulse = lim_impulse.select(use_min | use_max, _0);
}
}
WPrismaticVelocityGroundConstraint {
joint_id,
mj_lambda2,
im2,
ii2_sqrt,
impulse: impulse * SimdReal::splat(params.warmstart_coeff),
limits_impulse: limits_impulse * SimdReal::splat(params.warmstart_coeff),
basis1,
inv_lhs,
rhs,
r2,
axis2,
limits_forcedir2,
limits_rhs,
}
}
pub fn warmstart(&self, mj_lambdas: &mut [DeltaVel<Real>]) {
let mut mj_lambda2 = DeltaVel {
linear: Vector::from(
array![|ii| mj_lambdas[self.mj_lambda2[ii] as usize].linear; SIMD_WIDTH],
),
angular: AngVector::from(
array![|ii| mj_lambdas[self.mj_lambda2[ii] as usize].angular; SIMD_WIDTH],
),
};
let lin_impulse = self.basis1 * self.impulse.fixed_rows::<LinImpulseDim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = self.impulse.y;
#[cfg(feature = "dim3")]
let ang_impulse = self.impulse.fixed_rows::<U3>(2).into_owned();
mj_lambda2.linear -= lin_impulse * self.im2;
mj_lambda2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
if let Some(limits_forcedir2) = self.limits_forcedir2 {
mj_lambda2.linear += limits_forcedir2 * (self.im2 * self.limits_impulse);
}
for ii in 0..SIMD_WIDTH {
mj_lambdas[self.mj_lambda2[ii] as usize].linear = mj_lambda2.linear.extract(ii);
mj_lambdas[self.mj_lambda2[ii] as usize].angular = mj_lambda2.angular.extract(ii);
}
}
fn solve_dofs(&mut self, mj_lambda2: &mut DeltaVel<SimdReal>) {
let ang_vel2 = self.ii2_sqrt.transform_vector(mj_lambda2.angular);
let lin_vel2 = mj_lambda2.linear + ang_vel2.gcross(self.r2);
let lin_dvel = self.basis1.tr_mul(&lin_vel2);
let ang_dvel = ang_vel2;
#[cfg(feature = "dim2")]
let rhs = Vector2::new(lin_dvel.x, ang_dvel) + self.rhs;
#[cfg(feature = "dim3")]
let rhs =
Vector5::new(lin_dvel.x, lin_dvel.y, ang_dvel.x, ang_dvel.y, ang_dvel.z) + self.rhs;
let impulse = self.inv_lhs * rhs;
self.impulse += impulse;
let lin_impulse = self.basis1 * impulse.fixed_rows::<LinImpulseDim>(0).into_owned();
#[cfg(feature = "dim2")]
let ang_impulse = impulse.y;
#[cfg(feature = "dim3")]
let ang_impulse = impulse.fixed_rows::<U3>(2).into_owned();
mj_lambda2.linear -= lin_impulse * self.im2;
mj_lambda2.angular -= self
.ii2_sqrt
.transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
}
fn solve_limits(&mut self, mj_lambda2: &mut DeltaVel<SimdReal>) {
if let Some(limits_forcedir2) = self.limits_forcedir2 {
// FIXME: the transformation by ii2_sqrt could be avoided by
// reusing some computations above.
let ang_vel2 = self.ii2_sqrt.transform_vector(mj_lambda2.angular);
let lin_dvel = limits_forcedir2.dot(&(mj_lambda2.linear + ang_vel2.gcross(self.r2)))
+ self.limits_rhs;
let new_impulse = (self.limits_impulse - lin_dvel / self.im2).simd_max(na::zero());
let dimpulse = new_impulse - self.limits_impulse;
self.limits_impulse = new_impulse;
mj_lambda2.linear += limits_forcedir2 * (self.im2 * dimpulse);
}
}
pub fn solve(&mut self, mj_lambdas: &mut [DeltaVel<Real>]) {
let mut mj_lambda2 = DeltaVel {
linear: Vector::from(
array![|ii| mj_lambdas[self.mj_lambda2[ii] as usize].linear; SIMD_WIDTH],
),
angular: AngVector::from(
array![|ii| mj_lambdas[self.mj_lambda2[ii] as usize].angular; SIMD_WIDTH],
),
};
self.solve_dofs(&mut mj_lambda2);
self.solve_limits(&mut mj_lambda2);
for ii in 0..SIMD_WIDTH {
mj_lambdas[self.mj_lambda2[ii] as usize].linear = mj_lambda2.linear.extract(ii);
mj_lambdas[self.mj_lambda2[ii] as usize].angular = mj_lambda2.angular.extract(ii);
}
}
pub fn writeback_impulses(&self, joints_all: &mut [JointGraphEdge]) {
for ii in 0..SIMD_WIDTH {
let joint = &mut joints_all[self.joint_id[ii]].weight;
if let JointParams::PrismaticJoint(rev) = &mut joint.params {
rev.impulse = self.impulse.extract(ii);
rev.limits_impulse = self.limits_impulse.extract(ii);
}
}
}
}