245 lines
7.9 KiB
Rust
245 lines
7.9 KiB
Rust
use crate::dynamics::solver::DeltaVel;
|
|
use crate::dynamics::{
|
|
BallJoint, IntegrationParameters, JointGraphEdge, JointIndex, JointParams, RigidBody,
|
|
};
|
|
use crate::math::{AngularInertia, Real, SdpMatrix, Vector};
|
|
use crate::utils::{WAngularInertia, WCross, WCrossMatrix};
|
|
|
|
#[derive(Debug)]
|
|
pub(crate) struct BallVelocityConstraint {
|
|
mj_lambda1: usize,
|
|
mj_lambda2: usize,
|
|
|
|
joint_id: JointIndex,
|
|
|
|
rhs: Vector<Real>,
|
|
pub(crate) impulse: Vector<Real>,
|
|
|
|
r1: Vector<Real>,
|
|
r2: Vector<Real>,
|
|
|
|
inv_lhs: SdpMatrix<Real>,
|
|
|
|
im1: Real,
|
|
im2: Real,
|
|
|
|
ii1_sqrt: AngularInertia<Real>,
|
|
ii2_sqrt: AngularInertia<Real>,
|
|
}
|
|
|
|
impl BallVelocityConstraint {
|
|
pub fn from_params(
|
|
params: &IntegrationParameters,
|
|
joint_id: JointIndex,
|
|
rb1: &RigidBody,
|
|
rb2: &RigidBody,
|
|
cparams: &BallJoint,
|
|
) -> Self {
|
|
let anchor1 = rb1.position * cparams.local_anchor1 - rb1.world_com;
|
|
let anchor2 = rb2.position * cparams.local_anchor2 - rb2.world_com;
|
|
|
|
let vel1 = rb1.linvel + rb1.angvel.gcross(anchor1);
|
|
let vel2 = rb2.linvel + rb2.angvel.gcross(anchor2);
|
|
let im1 = rb1.effective_inv_mass;
|
|
let im2 = rb2.effective_inv_mass;
|
|
|
|
let rhs = -(vel1 - vel2);
|
|
let lhs;
|
|
|
|
let cmat1 = anchor1.gcross_matrix();
|
|
let cmat2 = anchor2.gcross_matrix();
|
|
|
|
#[cfg(feature = "dim3")]
|
|
{
|
|
lhs = rb2
|
|
.effective_world_inv_inertia_sqrt
|
|
.squared()
|
|
.quadform(&cmat2)
|
|
.add_diagonal(im2)
|
|
+ rb1
|
|
.effective_world_inv_inertia_sqrt
|
|
.squared()
|
|
.quadform(&cmat1)
|
|
.add_diagonal(im1);
|
|
}
|
|
|
|
// In 2D we just unroll the computation because
|
|
// it's just easier that way.
|
|
#[cfg(feature = "dim2")]
|
|
{
|
|
let ii1 = rb1.effective_world_inv_inertia_sqrt.squared();
|
|
let ii2 = rb2.effective_world_inv_inertia_sqrt.squared();
|
|
let m11 = im1 + im2 + cmat1.x * cmat1.x * ii1 + cmat2.x * cmat2.x * ii2;
|
|
let m12 = cmat1.x * cmat1.y * ii1 + cmat2.x * cmat2.y * ii2;
|
|
let m22 = im1 + im2 + cmat1.y * cmat1.y * ii1 + cmat2.y * cmat2.y * ii2;
|
|
lhs = SdpMatrix::new(m11, m12, m22)
|
|
}
|
|
|
|
let inv_lhs = lhs.inverse_unchecked();
|
|
|
|
BallVelocityConstraint {
|
|
joint_id,
|
|
mj_lambda1: rb1.active_set_offset,
|
|
mj_lambda2: rb2.active_set_offset,
|
|
im1,
|
|
im2,
|
|
impulse: cparams.impulse * params.warmstart_coeff,
|
|
r1: anchor1,
|
|
r2: anchor2,
|
|
rhs,
|
|
inv_lhs,
|
|
ii1_sqrt: rb1.effective_world_inv_inertia_sqrt,
|
|
ii2_sqrt: rb2.effective_world_inv_inertia_sqrt,
|
|
}
|
|
}
|
|
|
|
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];
|
|
|
|
mj_lambda1.linear += self.im1 * self.impulse;
|
|
mj_lambda1.angular += self.ii1_sqrt.transform_vector(self.r1.gcross(self.impulse));
|
|
mj_lambda2.linear -= self.im2 * self.impulse;
|
|
mj_lambda2.angular -= self.ii2_sqrt.transform_vector(self.r2.gcross(self.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>]) {
|
|
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 vel1 = mj_lambda1.linear + ang_vel1.gcross(self.r1);
|
|
let vel2 = mj_lambda2.linear + ang_vel2.gcross(self.r2);
|
|
let dvel = -vel1 + vel2 + self.rhs;
|
|
|
|
let impulse = self.inv_lhs * dvel;
|
|
self.impulse += impulse;
|
|
|
|
mj_lambda1.linear += self.im1 * impulse;
|
|
mj_lambda1.angular += self.ii1_sqrt.transform_vector(self.r1.gcross(impulse));
|
|
|
|
mj_lambda2.linear -= self.im2 * impulse;
|
|
mj_lambda2.angular -= self.ii2_sqrt.transform_vector(self.r2.gcross(impulse));
|
|
|
|
mj_lambdas[self.mj_lambda1 as usize] = mj_lambda1;
|
|
mj_lambdas[self.mj_lambda2 as usize] = mj_lambda2;
|
|
}
|
|
|
|
pub fn writeback_impulses(&self, joints_all: &mut [JointGraphEdge]) {
|
|
let joint = &mut joints_all[self.joint_id].weight;
|
|
if let JointParams::BallJoint(ball) = &mut joint.params {
|
|
ball.impulse = self.impulse
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Debug)]
|
|
pub(crate) struct BallVelocityGroundConstraint {
|
|
mj_lambda2: usize,
|
|
joint_id: JointIndex,
|
|
rhs: Vector<Real>,
|
|
impulse: Vector<Real>,
|
|
r2: Vector<Real>,
|
|
inv_lhs: SdpMatrix<Real>,
|
|
im2: Real,
|
|
ii2_sqrt: AngularInertia<Real>,
|
|
}
|
|
|
|
impl BallVelocityGroundConstraint {
|
|
pub fn from_params(
|
|
params: &IntegrationParameters,
|
|
joint_id: JointIndex,
|
|
rb1: &RigidBody,
|
|
rb2: &RigidBody,
|
|
cparams: &BallJoint,
|
|
flipped: bool,
|
|
) -> Self {
|
|
let (anchor1, anchor2) = if flipped {
|
|
(
|
|
rb1.position * cparams.local_anchor2 - rb1.world_com,
|
|
rb2.position * cparams.local_anchor1 - rb2.world_com,
|
|
)
|
|
} else {
|
|
(
|
|
rb1.position * cparams.local_anchor1 - rb1.world_com,
|
|
rb2.position * cparams.local_anchor2 - rb2.world_com,
|
|
)
|
|
};
|
|
|
|
let im2 = rb2.effective_inv_mass;
|
|
let vel1 = rb1.linvel + rb1.angvel.gcross(anchor1);
|
|
let vel2 = rb2.linvel + rb2.angvel.gcross(anchor2);
|
|
let rhs = vel2 - vel1;
|
|
|
|
let cmat2 = anchor2.gcross_matrix();
|
|
|
|
let lhs;
|
|
|
|
#[cfg(feature = "dim3")]
|
|
{
|
|
lhs = rb2
|
|
.effective_world_inv_inertia_sqrt
|
|
.squared()
|
|
.quadform(&cmat2)
|
|
.add_diagonal(im2);
|
|
}
|
|
|
|
#[cfg(feature = "dim2")]
|
|
{
|
|
let ii2 = rb2.effective_world_inv_inertia_sqrt.squared();
|
|
let m11 = im2 + cmat2.x * cmat2.x * ii2;
|
|
let m12 = cmat2.x * cmat2.y * ii2;
|
|
let m22 = im2 + cmat2.y * cmat2.y * ii2;
|
|
lhs = SdpMatrix::new(m11, m12, m22)
|
|
}
|
|
|
|
let inv_lhs = lhs.inverse_unchecked();
|
|
|
|
BallVelocityGroundConstraint {
|
|
joint_id,
|
|
mj_lambda2: rb2.active_set_offset,
|
|
im2,
|
|
impulse: cparams.impulse * params.warmstart_coeff,
|
|
r2: anchor2,
|
|
rhs,
|
|
inv_lhs,
|
|
ii2_sqrt: rb2.effective_world_inv_inertia_sqrt,
|
|
}
|
|
}
|
|
|
|
pub fn warmstart(&self, mj_lambdas: &mut [DeltaVel<Real>]) {
|
|
let mut mj_lambda2 = mj_lambdas[self.mj_lambda2 as usize];
|
|
mj_lambda2.linear -= self.im2 * self.impulse;
|
|
mj_lambda2.angular -= self.ii2_sqrt.transform_vector(self.r2.gcross(self.impulse));
|
|
mj_lambdas[self.mj_lambda2 as usize] = mj_lambda2;
|
|
}
|
|
|
|
pub fn solve(&mut self, mj_lambdas: &mut [DeltaVel<Real>]) {
|
|
let mut mj_lambda2 = mj_lambdas[self.mj_lambda2 as usize];
|
|
|
|
let angvel = self.ii2_sqrt.transform_vector(mj_lambda2.angular);
|
|
let vel2 = mj_lambda2.linear + angvel.gcross(self.r2);
|
|
let dvel = vel2 + self.rhs;
|
|
|
|
let impulse = self.inv_lhs * dvel;
|
|
self.impulse += impulse;
|
|
|
|
mj_lambda2.linear -= self.im2 * impulse;
|
|
mj_lambda2.angular -= self.ii2_sqrt.transform_vector(self.r2.gcross(impulse));
|
|
|
|
mj_lambdas[self.mj_lambda2 as usize] = mj_lambda2;
|
|
}
|
|
|
|
// 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::BallJoint(ball) = &mut joint.params {
|
|
ball.impulse = self.impulse
|
|
}
|
|
}
|
|
}
|