471 lines
18 KiB
Rust
471 lines
18 KiB
Rust
use super::{ContactConstraintTypes, ContactPointInfos};
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use crate::dynamics::solver::SolverVel;
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use crate::dynamics::solver::{AnyConstraintMut, SolverBody};
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use crate::dynamics::{IntegrationParameters, MultibodyJointSet, RigidBodySet};
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use crate::geometry::{ContactManifold, ContactManifoldIndex};
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use crate::math::{Isometry, Real, Vector, DIM, MAX_MANIFOLD_POINTS};
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use crate::utils::{self, SimdAngularInertia, SimdBasis, SimdCross, SimdDot};
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use na::DVector;
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use super::{TwoBodyConstraintElement, TwoBodyConstraintNormalPart};
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impl<'a> AnyConstraintMut<'a, ContactConstraintTypes> {
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pub fn remove_bias(&mut self) {
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match self {
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Self::OneBody(c) => c.remove_cfm_and_bias_from_rhs(),
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Self::TwoBodies(c) => c.remove_cfm_and_bias_from_rhs(),
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Self::GenericOneBody(c) => c.remove_cfm_and_bias_from_rhs(),
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Self::GenericTwoBodies(c) => c.remove_cfm_and_bias_from_rhs(),
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#[cfg(feature = "simd-is-enabled")]
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Self::SimdOneBody(c) => c.remove_cfm_and_bias_from_rhs(),
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#[cfg(feature = "simd-is-enabled")]
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Self::SimdTwoBodies(c) => c.remove_cfm_and_bias_from_rhs(),
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}
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}
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pub fn solve_restitution(
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&mut self,
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generic_jacobians: &DVector<Real>,
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solver_vels: &mut [SolverVel<Real>],
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generic_solver_vels: &mut DVector<Real>,
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) {
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match self {
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Self::OneBody(c) => c.solve(solver_vels, true, false),
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Self::TwoBodies(c) => c.solve(solver_vels, true, false),
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Self::GenericOneBody(c) => c.solve(generic_jacobians, generic_solver_vels, true, false),
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Self::GenericTwoBodies(c) => c.solve(
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generic_jacobians,
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solver_vels,
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generic_solver_vels,
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true,
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false,
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),
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#[cfg(feature = "simd-is-enabled")]
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Self::SimdOneBody(c) => c.solve(solver_vels, true, false),
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#[cfg(feature = "simd-is-enabled")]
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Self::SimdTwoBodies(c) => c.solve(solver_vels, true, false),
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}
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}
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pub fn solve_friction(
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&mut self,
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generic_jacobians: &DVector<Real>,
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solver_vels: &mut [SolverVel<Real>],
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generic_solver_vels: &mut DVector<Real>,
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) {
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match self {
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Self::OneBody(c) => c.solve(solver_vels, false, true),
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Self::TwoBodies(c) => c.solve(solver_vels, false, true),
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Self::GenericOneBody(c) => c.solve(generic_jacobians, generic_solver_vels, false, true),
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Self::GenericTwoBodies(c) => c.solve(
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generic_jacobians,
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solver_vels,
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generic_solver_vels,
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false,
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true,
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),
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#[cfg(feature = "simd-is-enabled")]
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Self::SimdOneBody(c) => c.solve(solver_vels, false, true),
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#[cfg(feature = "simd-is-enabled")]
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Self::SimdTwoBodies(c) => c.solve(solver_vels, false, true),
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}
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}
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pub fn writeback_impulses(&mut self, manifolds_all: &mut [&mut ContactManifold]) {
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match self {
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Self::OneBody(c) => c.writeback_impulses(manifolds_all),
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Self::TwoBodies(c) => c.writeback_impulses(manifolds_all),
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Self::GenericOneBody(c) => c.writeback_impulses(manifolds_all),
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Self::GenericTwoBodies(c) => c.writeback_impulses(manifolds_all),
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#[cfg(feature = "simd-is-enabled")]
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Self::SimdOneBody(c) => c.writeback_impulses(manifolds_all),
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#[cfg(feature = "simd-is-enabled")]
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Self::SimdTwoBodies(c) => c.writeback_impulses(manifolds_all),
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}
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}
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}
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#[derive(Copy, Clone, Debug)]
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pub(crate) struct TwoBodyConstraint {
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pub dir1: Vector<Real>, // Non-penetration force direction for the first body.
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#[cfg(feature = "dim3")]
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pub tangent1: Vector<Real>, // One of the friction force directions.
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pub im1: Vector<Real>,
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pub im2: Vector<Real>,
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pub cfm_factor: Real,
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pub limit: Real,
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pub solver_vel1: usize,
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pub solver_vel2: usize,
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pub manifold_id: ContactManifoldIndex,
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pub manifold_contact_id: [u8; MAX_MANIFOLD_POINTS],
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pub num_contacts: u8,
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pub elements: [TwoBodyConstraintElement<Real>; MAX_MANIFOLD_POINTS],
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}
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impl TwoBodyConstraint {
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pub fn invalid() -> Self {
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Self {
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dir1: Vector::zeros(),
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#[cfg(feature = "dim3")]
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tangent1: Vector::zeros(),
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im1: Vector::zeros(),
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im2: Vector::zeros(),
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cfm_factor: 0.0,
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limit: 0.0,
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solver_vel1: usize::MAX,
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solver_vel2: usize::MAX,
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manifold_id: ContactManifoldIndex::MAX,
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manifold_contact_id: [u8::MAX; MAX_MANIFOLD_POINTS],
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num_contacts: u8::MAX,
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elements: [TwoBodyConstraintElement::zero(); MAX_MANIFOLD_POINTS],
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}
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}
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}
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#[derive(Copy, Clone, Debug)]
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pub(crate) struct TwoBodyConstraintBuilder {
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pub infos: [ContactPointInfos<Real>; MAX_MANIFOLD_POINTS],
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}
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impl TwoBodyConstraintBuilder {
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pub fn invalid() -> Self {
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Self {
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infos: [ContactPointInfos::default(); MAX_MANIFOLD_POINTS],
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}
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}
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pub fn generate(
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manifold_id: ContactManifoldIndex,
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manifold: &ContactManifold,
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bodies: &RigidBodySet,
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out_builders: &mut [TwoBodyConstraintBuilder],
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out_constraints: &mut [TwoBodyConstraint],
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) {
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assert_eq!(manifold.data.relative_dominance, 0);
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let handle1 = manifold.data.rigid_body1.unwrap();
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let handle2 = manifold.data.rigid_body2.unwrap();
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let rb1 = &bodies[handle1];
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let (vels1, mprops1) = (&rb1.vels, &rb1.mprops);
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let rb2 = &bodies[handle2];
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let (vels2, mprops2) = (&rb2.vels, &rb2.mprops);
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let solver_vel1 = rb1.ids.active_set_offset;
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let solver_vel2 = rb2.ids.active_set_offset;
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let force_dir1 = -manifold.data.normal;
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#[cfg(feature = "dim2")]
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let tangents1 = force_dir1.orthonormal_basis();
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#[cfg(feature = "dim3")]
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let tangents1 =
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super::compute_tangent_contact_directions(&force_dir1, &vels1.linvel, &vels2.linvel);
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for (l, manifold_points) in manifold
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.data
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.solver_contacts
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.chunks(MAX_MANIFOLD_POINTS)
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.enumerate()
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{
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let builder = &mut out_builders[l];
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let constraint = &mut out_constraints[l];
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constraint.dir1 = force_dir1;
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constraint.im1 = mprops1.effective_inv_mass;
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constraint.im2 = mprops2.effective_inv_mass;
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constraint.solver_vel1 = solver_vel1;
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constraint.solver_vel2 = solver_vel2;
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constraint.manifold_id = manifold_id;
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constraint.num_contacts = manifold_points.len() as u8;
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#[cfg(feature = "dim3")]
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{
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constraint.tangent1 = tangents1[0];
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}
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for k in 0..manifold_points.len() {
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let manifold_point = &manifold_points[k];
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let point = manifold_point.point;
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let dp1 = point - mprops1.world_com;
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let dp2 = point - mprops2.world_com;
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let vel1 = vels1.linvel + vels1.angvel.gcross(dp1);
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let vel2 = vels2.linvel + vels2.angvel.gcross(dp2);
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constraint.limit = manifold_point.friction;
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constraint.manifold_contact_id[k] = manifold_point.contact_id;
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// Normal part.
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let normal_rhs_wo_bias;
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{
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let gcross1 = mprops1
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.effective_world_inv_inertia_sqrt
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.transform_vector(dp1.gcross(force_dir1));
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let gcross2 = mprops2
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.effective_world_inv_inertia_sqrt
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.transform_vector(dp2.gcross(-force_dir1));
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let imsum = mprops1.effective_inv_mass + mprops2.effective_inv_mass;
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let projected_mass = utils::inv(
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force_dir1.dot(&imsum.component_mul(&force_dir1))
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+ gcross1.gdot(gcross1)
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+ gcross2.gdot(gcross2),
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);
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let is_bouncy = manifold_point.is_bouncy() as u32 as Real;
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normal_rhs_wo_bias =
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(is_bouncy * manifold_point.restitution) * (vel1 - vel2).dot(&force_dir1);
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constraint.elements[k].normal_part = TwoBodyConstraintNormalPart {
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gcross1,
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gcross2,
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rhs: na::zero(),
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rhs_wo_bias: na::zero(),
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impulse: na::zero(),
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total_impulse: na::zero(),
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r: projected_mass,
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};
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}
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// Tangent parts.
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{
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constraint.elements[k].tangent_part.impulse = na::zero();
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for j in 0..DIM - 1 {
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let gcross1 = mprops1
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.effective_world_inv_inertia_sqrt
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.transform_vector(dp1.gcross(tangents1[j]));
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let gcross2 = mprops2
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.effective_world_inv_inertia_sqrt
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.transform_vector(dp2.gcross(-tangents1[j]));
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let imsum = mprops1.effective_inv_mass + mprops2.effective_inv_mass;
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let r = tangents1[j].dot(&imsum.component_mul(&tangents1[j]))
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+ gcross1.gdot(gcross1)
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+ gcross2.gdot(gcross2);
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let rhs_wo_bias = manifold_point.tangent_velocity.dot(&tangents1[j]);
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constraint.elements[k].tangent_part.gcross1[j] = gcross1;
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constraint.elements[k].tangent_part.gcross2[j] = gcross2;
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constraint.elements[k].tangent_part.rhs_wo_bias[j] = rhs_wo_bias;
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constraint.elements[k].tangent_part.rhs[j] = rhs_wo_bias;
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constraint.elements[k].tangent_part.r[j] = if cfg!(feature = "dim2") {
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utils::inv(r)
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} else {
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r
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};
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}
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#[cfg(feature = "dim3")]
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{
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constraint.elements[k].tangent_part.r[2] = 2.0
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* (constraint.elements[k].tangent_part.gcross1[0]
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.gdot(constraint.elements[k].tangent_part.gcross1[1])
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+ constraint.elements[k].tangent_part.gcross2[0]
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.gdot(constraint.elements[k].tangent_part.gcross2[1]));
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}
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}
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// Builder.
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let infos = ContactPointInfos {
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local_p1: rb1
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.pos
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.position
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.inverse_transform_point(&manifold_point.point),
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local_p2: rb2
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.pos
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.position
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.inverse_transform_point(&manifold_point.point),
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tangent_vel: manifold_point.tangent_velocity,
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dist: manifold_point.dist,
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normal_rhs_wo_bias,
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};
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builder.infos[k] = infos;
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constraint.manifold_contact_id[k] = manifold_point.contact_id;
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}
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}
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}
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pub fn update(
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&self,
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params: &IntegrationParameters,
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solved_dt: Real,
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bodies: &[SolverBody],
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_multibodies: &MultibodyJointSet,
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constraint: &mut TwoBodyConstraint,
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) {
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let rb1 = &bodies[constraint.solver_vel1];
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let rb2 = &bodies[constraint.solver_vel2];
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let ccd_thickness = rb1.ccd_thickness + rb2.ccd_thickness;
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self.update_with_positions(
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params,
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solved_dt,
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&rb1.position,
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&rb2.position,
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ccd_thickness,
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constraint,
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)
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}
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// Used by both generic and non-generic builders..
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pub fn update_with_positions(
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&self,
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params: &IntegrationParameters,
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solved_dt: Real,
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rb1_pos: &Isometry<Real>,
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rb2_pos: &Isometry<Real>,
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ccd_thickness: Real,
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constraint: &mut TwoBodyConstraint,
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) {
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let cfm_factor = params.cfm_factor();
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let inv_dt = params.inv_dt();
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let erp_inv_dt = params.erp_inv_dt();
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let all_infos = &self.infos[..constraint.num_contacts as usize];
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let all_elements = &mut constraint.elements[..constraint.num_contacts as usize];
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let mut is_fast_contact = false;
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#[cfg(feature = "dim2")]
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let tangents1 = constraint.dir1.orthonormal_basis();
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#[cfg(feature = "dim3")]
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let tangents1 = [
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constraint.tangent1,
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constraint.dir1.cross(&constraint.tangent1),
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];
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for (info, element) in all_infos.iter().zip(all_elements.iter_mut()) {
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// Tangent velocity is equivalent to the first body’s surface moving artificially.
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let p1 = rb1_pos * info.local_p1 + info.tangent_vel * solved_dt;
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let p2 = rb2_pos * info.local_p2;
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let dist = info.dist + (p1 - p2).dot(&constraint.dir1);
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// Normal part.
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{
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let rhs_wo_bias = info.normal_rhs_wo_bias + dist.max(0.0) * inv_dt;
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let rhs_bias = erp_inv_dt
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* (dist + params.allowed_linear_error)
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.clamp(-params.max_penetration_correction, 0.0);
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let new_rhs = rhs_wo_bias + rhs_bias;
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let total_impulse = element.normal_part.total_impulse + element.normal_part.impulse;
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is_fast_contact = is_fast_contact || (-new_rhs * params.dt > ccd_thickness * 0.5);
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element.normal_part.rhs_wo_bias = rhs_wo_bias;
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element.normal_part.rhs = new_rhs;
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element.normal_part.total_impulse = total_impulse;
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element.normal_part.impulse = na::zero();
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}
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// Tangent part.
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{
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element.tangent_part.total_impulse += element.tangent_part.impulse;
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element.tangent_part.impulse = na::zero();
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for j in 0..DIM - 1 {
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let bias = (p1 - p2).dot(&tangents1[j]) * inv_dt;
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element.tangent_part.rhs[j] = element.tangent_part.rhs_wo_bias[j] + bias;
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}
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}
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}
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constraint.cfm_factor = if is_fast_contact { 1.0 } else { cfm_factor };
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}
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}
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impl TwoBodyConstraint {
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pub fn solve(
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&mut self,
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solver_vels: &mut [SolverVel<Real>],
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solve_normal: bool,
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solve_friction: bool,
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) {
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let mut solver_vel1 = solver_vels[self.solver_vel1 as usize];
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let mut solver_vel2 = solver_vels[self.solver_vel2 as usize];
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TwoBodyConstraintElement::solve_group(
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self.cfm_factor,
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&mut self.elements[..self.num_contacts as usize],
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&self.dir1,
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#[cfg(feature = "dim3")]
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&self.tangent1,
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&self.im1,
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&self.im2,
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self.limit,
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&mut solver_vel1,
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&mut solver_vel2,
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solve_normal,
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solve_friction,
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);
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solver_vels[self.solver_vel1 as usize] = solver_vel1;
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solver_vels[self.solver_vel2 as usize] = solver_vel2;
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}
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pub fn writeback_impulses(&self, manifolds_all: &mut [&mut ContactManifold]) {
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let manifold = &mut manifolds_all[self.manifold_id];
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for k in 0..self.num_contacts as usize {
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let contact_id = self.manifold_contact_id[k];
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let active_contact = &mut manifold.points[contact_id as usize];
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active_contact.data.impulse = self.elements[k].normal_part.impulse;
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#[cfg(feature = "dim2")]
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{
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active_contact.data.tangent_impulse = self.elements[k].tangent_part.impulse[0];
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}
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#[cfg(feature = "dim3")]
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{
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active_contact.data.tangent_impulse = self.elements[k].tangent_part.impulse;
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}
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}
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}
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pub fn remove_cfm_and_bias_from_rhs(&mut self) {
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self.cfm_factor = 1.0;
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for elt in &mut self.elements {
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elt.normal_part.rhs = elt.normal_part.rhs_wo_bias;
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// elt.normal_part.impulse = elt.normal_part.total_impulse;
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elt.tangent_part.rhs = elt.tangent_part.rhs_wo_bias;
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// elt.tangent_part.impulse = elt.tangent_part.total_impulse;
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}
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}
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}
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#[inline(always)]
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#[cfg(feature = "dim3")]
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pub(crate) fn compute_tangent_contact_directions<N>(
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force_dir1: &Vector<N>,
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linvel1: &Vector<N>,
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linvel2: &Vector<N>,
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) -> [Vector<N>; DIM - 1]
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where
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N: utils::SimdRealCopy,
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Vector<N>: SimdBasis,
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{
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use na::SimdValue;
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// Compute the tangent direction. Pick the direction of
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// the linear relative velocity, if it is not too small.
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// Otherwise use a fallback direction.
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let relative_linvel = linvel1 - linvel2;
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let mut tangent_relative_linvel =
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relative_linvel - force_dir1 * (force_dir1.dot(&relative_linvel));
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let tangent_linvel_norm = {
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let _disable_fe_except =
|
||
crate::utils::DisableFloatingPointExceptionsFlags::disable_floating_point_exceptions();
|
||
tangent_relative_linvel.normalize_mut()
|
||
};
|
||
|
||
const THRESHOLD: Real = 1.0e-4;
|
||
let use_fallback = tangent_linvel_norm.simd_lt(N::splat(THRESHOLD));
|
||
let tangent_fallback = force_dir1.orthonormal_vector();
|
||
|
||
let tangent1 = tangent_fallback.select(use_fallback, tangent_relative_linvel);
|
||
let bitangent1 = force_dir1.cross(&tangent1);
|
||
|
||
[tangent1, bitangent1]
|
||
}
|