Files
rapier/src/dynamics/solver/joint_constraint/generic_position_constraint.rs

347 lines
12 KiB
Rust

use super::{GenericVelocityConstraint, GenericVelocityGroundConstraint};
use crate::dynamics::solver::DeltaVel;
use crate::dynamics::{GenericJoint, IntegrationParameters, RigidBody};
use crate::math::{
AngDim, AngVector, AngularInertia, Dim, Isometry, Point, Real, Rotation, SpatialVector, Vector,
DIM,
};
use crate::utils::{WAngularInertia, WCross, WCrossMatrix};
use na::{Vector3, Vector6};
// FIXME: review this code for the case where the center of masses are not the origin.
#[derive(Debug)]
pub(crate) struct GenericPositionConstraint {
position1: usize,
position2: usize,
local_anchor1: Isometry<Real>,
local_anchor2: Isometry<Real>,
local_com1: Point<Real>,
local_com2: Point<Real>,
im1: Real,
im2: Real,
ii1: AngularInertia<Real>,
ii2: AngularInertia<Real>,
joint: GenericJoint,
}
impl GenericPositionConstraint {
pub fn from_params(rb1: &RigidBody, rb2: &RigidBody, joint: &GenericJoint) -> Self {
let ii1 = rb1.effective_world_inv_inertia_sqrt.squared();
let ii2 = rb2.effective_world_inv_inertia_sqrt.squared();
let im1 = rb1.effective_inv_mass;
let im2 = rb2.effective_inv_mass;
Self {
local_anchor1: joint.local_anchor1,
local_anchor2: joint.local_anchor2,
position1: rb1.active_set_offset,
position2: rb2.active_set_offset,
im1,
im2,
ii1,
ii2,
local_com1: rb1.mass_properties.local_com,
local_com2: rb2.mass_properties.local_com,
joint: *joint,
}
}
pub fn solve(&self, params: &IntegrationParameters, positions: &mut [Isometry<Real>]) {
let mut position1 = positions[self.position1];
let mut position2 = positions[self.position2];
let mut params = *params;
params.joint_erp = 0.8;
/*
*
* Translation part.
*
*/
{
let anchor1 = position1 * self.joint.local_anchor1;
let anchor2 = position2 * self.joint.local_anchor2;
let basis = anchor1.rotation;
let r1 = Point::from(anchor1.translation.vector) - position1 * self.local_com1;
let r2 = Point::from(anchor2.translation.vector) - position2 * self.local_com2;
let mut min_pos_impulse = self.joint.min_pos_impulse.xyz();
let mut max_pos_impulse = self.joint.max_pos_impulse.xyz();
let pos_rhs = GenericVelocityConstraint::compute_lin_position_error(
&anchor1,
&anchor2,
&basis,
&self.joint.min_position.xyz(),
&self.joint.max_position.xyz(),
) * params.joint_erp;
for i in 0..3 {
if pos_rhs[i] < 0.0 {
min_pos_impulse[i] = -Real::MAX;
}
if pos_rhs[i] > 0.0 {
max_pos_impulse[i] = Real::MAX;
}
}
let rotmat = basis.to_rotation_matrix().into_inner();
let rmat1 = r1.gcross_matrix() * rotmat;
let rmat2 = r2.gcross_matrix() * rotmat;
// Will be actually inverted right after.
// TODO: we should keep the SdpMatrix3 type.
let delassus = (self.ii1.quadform(&rmat1).add_diagonal(self.im1)
+ self.ii2.quadform(&rmat2).add_diagonal(self.im2))
.into_matrix();
let inv_delassus = GenericVelocityConstraint::invert_partial_delassus_matrix(
&min_pos_impulse,
&max_pos_impulse,
&mut Vector3::zeros(),
delassus,
);
let local_impulse = (inv_delassus * pos_rhs)
.inf(&max_pos_impulse)
.sup(&min_pos_impulse);
let impulse = basis * local_impulse;
let rot1 = self.ii1.transform_vector(r1.gcross(impulse));
let rot2 = self.ii2.transform_vector(r2.gcross(impulse));
position1.translation.vector += self.im1 * impulse;
position1.rotation = position1.rotation.append_axisangle_linearized(&rot1);
position2.translation.vector -= self.im2 * impulse;
position2.rotation = position2.rotation.append_axisangle_linearized(&-rot2);
}
/*
*
* Rotation part
*
*/
{
let anchor1 = position1 * self.joint.local_anchor1;
let anchor2 = position2 * self.joint.local_anchor2;
let basis = anchor1.rotation;
let mut min_pos_impulse = self
.joint
.min_pos_impulse
.fixed_rows::<Dim>(DIM)
.into_owned();
let mut max_pos_impulse = self
.joint
.max_pos_impulse
.fixed_rows::<Dim>(DIM)
.into_owned();
let pos_rhs = GenericVelocityConstraint::compute_ang_position_error(
&anchor1,
&anchor2,
&basis,
&self.joint.min_position.fixed_rows::<Dim>(DIM).into_owned(),
&self.joint.max_position.fixed_rows::<Dim>(DIM).into_owned(),
) * params.joint_erp;
for i in 0..3 {
if pos_rhs[i] < 0.0 {
min_pos_impulse[i] = -Real::MAX;
}
if pos_rhs[i] > 0.0 {
max_pos_impulse[i] = Real::MAX;
}
}
// TODO: we should keep the SdpMatrix3 type.
let rotmat = basis.to_rotation_matrix().into_inner();
let delassus = (self.ii1.quadform(&rotmat) + self.ii2.quadform(&rotmat)).into_matrix();
let inv_delassus = GenericVelocityConstraint::invert_partial_delassus_matrix(
&min_pos_impulse,
&max_pos_impulse,
&mut Vector3::zeros(),
delassus,
);
let local_impulse = (inv_delassus * pos_rhs)
.inf(&max_pos_impulse)
.sup(&min_pos_impulse);
let impulse = basis * local_impulse;
let rot1 = self.ii1.transform_vector(impulse);
let rot2 = self.ii2.transform_vector(impulse);
position1.rotation = position1.rotation.append_axisangle_linearized(&rot1);
position2.rotation = position2.rotation.append_axisangle_linearized(&-rot2);
}
positions[self.position1] = position1;
positions[self.position2] = position2;
}
}
#[derive(Debug)]
pub(crate) struct GenericPositionGroundConstraint {
position2: usize,
anchor1: Isometry<Real>,
local_anchor2: Isometry<Real>,
local_com2: Point<Real>,
im2: Real,
ii2: AngularInertia<Real>,
joint: GenericJoint,
}
impl GenericPositionGroundConstraint {
pub fn from_params(
rb1: &RigidBody,
rb2: &RigidBody,
joint: &GenericJoint,
flipped: bool,
) -> Self {
let anchor1;
let local_anchor2;
if flipped {
anchor1 = rb1.predicted_position * joint.local_anchor2;
local_anchor2 = joint.local_anchor1;
} else {
anchor1 = rb1.predicted_position * joint.local_anchor1;
local_anchor2 = joint.local_anchor2;
};
Self {
anchor1,
local_anchor2,
position2: rb2.active_set_offset,
im2: rb2.effective_inv_mass,
ii2: rb2.effective_world_inv_inertia_sqrt.squared(),
local_com2: rb2.mass_properties.local_com,
joint: *joint,
}
}
pub fn solve(&self, params: &IntegrationParameters, positions: &mut [Isometry<Real>]) {
let mut position2 = positions[self.position2];
let mut params = *params;
params.joint_erp = 0.8;
/*
*
* Translation part.
*
*/
{
let anchor1 = self.anchor1;
let anchor2 = position2 * self.local_anchor2;
let basis = anchor1.rotation;
let r2 = Point::from(anchor2.translation.vector) - position2 * self.local_com2;
let mut min_pos_impulse = self.joint.min_pos_impulse.xyz();
let mut max_pos_impulse = self.joint.max_pos_impulse.xyz();
let pos_rhs = GenericVelocityConstraint::compute_lin_position_error(
&anchor1,
&anchor2,
&basis,
&self.joint.min_position.xyz(),
&self.joint.max_position.xyz(),
) * params.joint_erp;
for i in 0..3 {
if pos_rhs[i] < 0.0 {
min_pos_impulse[i] = -Real::MAX;
}
if pos_rhs[i] > 0.0 {
max_pos_impulse[i] = Real::MAX;
}
}
let rotmat = basis.to_rotation_matrix().into_inner();
let rmat2 = r2.gcross_matrix() * rotmat;
// TODO: we should keep the SdpMatrix3 type.
let delassus = self
.ii2
.quadform(&rmat2)
.add_diagonal(self.im2)
.into_matrix();
let inv_delassus = GenericVelocityConstraint::invert_partial_delassus_matrix(
&min_pos_impulse,
&max_pos_impulse,
&mut Vector3::zeros(),
delassus,
);
let local_impulse = (inv_delassus * pos_rhs)
.inf(&max_pos_impulse)
.sup(&min_pos_impulse);
let impulse = basis * local_impulse;
let rot2 = self.ii2.transform_vector(r2.gcross(impulse));
position2.translation.vector -= self.im2 * impulse;
position2.rotation = position2.rotation.append_axisangle_linearized(&-rot2);
}
/*
*
* Rotation part
*
*/
{
let anchor1 = self.anchor1;
let anchor2 = position2 * self.local_anchor2;
let basis = anchor1.rotation;
let mut min_pos_impulse = self
.joint
.min_pos_impulse
.fixed_rows::<Dim>(DIM)
.into_owned();
let mut max_pos_impulse = self
.joint
.max_pos_impulse
.fixed_rows::<Dim>(DIM)
.into_owned();
let pos_rhs = GenericVelocityConstraint::compute_ang_position_error(
&anchor1,
&anchor2,
&basis,
&self.joint.min_position.fixed_rows::<Dim>(DIM).into_owned(),
&self.joint.max_position.fixed_rows::<Dim>(DIM).into_owned(),
) * params.joint_erp;
for i in 0..3 {
if pos_rhs[i] < 0.0 {
min_pos_impulse[i] = -Real::MAX;
}
if pos_rhs[i] > 0.0 {
max_pos_impulse[i] = Real::MAX;
}
}
// Will be actually inverted right after.
// TODO: we should keep the SdpMatrix3 type.
let rotmat = basis.to_rotation_matrix().into_inner();
let delassus = self.ii2.quadform(&rotmat).into_matrix();
let inv_delassus = GenericVelocityConstraint::invert_partial_delassus_matrix(
&min_pos_impulse,
&max_pos_impulse,
&mut Vector3::zeros(),
delassus,
);
let local_impulse = (inv_delassus * pos_rhs)
.inf(&max_pos_impulse)
.sup(&min_pos_impulse);
let impulse = basis * local_impulse;
let rot2 = self.ii2.transform_vector(impulse);
position2.rotation = position2.rotation.append_axisangle_linearized(&-rot2);
}
positions[self.position2] = position2;
}
}