Files
rapier/src/dynamics/solver/generic_velocity_constraint.rs
2022-01-23 16:50:26 +01:00

443 lines
17 KiB
Rust

use crate::data::{BundleSet, ComponentSet};
use crate::dynamics::solver::{GenericRhs, VelocityConstraint};
use crate::dynamics::{
IntegrationParameters, MultibodyJointSet, RigidBodyIds, RigidBodyMassProps, RigidBodyType,
RigidBodyVelocity,
};
use crate::geometry::{ContactManifold, ContactManifoldIndex};
use crate::math::{Real, DIM, MAX_MANIFOLD_POINTS};
use crate::utils::{WAngularInertia, WCross, WDot};
use super::{DeltaVel, VelocityConstraintElement, VelocityConstraintNormalPart};
use crate::dynamics::solver::GenericVelocityGroundConstraint;
#[cfg(feature = "dim2")]
use crate::utils::WBasis;
use na::DVector;
#[derive(Copy, Clone, Debug)]
pub(crate) enum AnyGenericVelocityConstraint {
NongroupedGround(GenericVelocityGroundConstraint),
Nongrouped(GenericVelocityConstraint),
}
impl AnyGenericVelocityConstraint {
pub fn solve(
&mut self,
cfm_factor: Real,
jacobians: &DVector<Real>,
mj_lambdas: &mut [DeltaVel<Real>],
generic_mj_lambdas: &mut DVector<Real>,
solve_restitution: bool,
solve_friction: bool,
) {
match self {
AnyGenericVelocityConstraint::Nongrouped(c) => c.solve(
cfm_factor,
jacobians,
mj_lambdas,
generic_mj_lambdas,
solve_restitution,
solve_friction,
),
AnyGenericVelocityConstraint::NongroupedGround(c) => c.solve(
cfm_factor,
jacobians,
generic_mj_lambdas,
solve_restitution,
solve_friction,
),
}
}
pub fn writeback_impulses(&self, manifolds_all: &mut [&mut ContactManifold]) {
match self {
AnyGenericVelocityConstraint::Nongrouped(c) => c.writeback_impulses(manifolds_all),
AnyGenericVelocityConstraint::NongroupedGround(c) => {
c.writeback_impulses(manifolds_all)
}
}
}
pub fn remove_bias_from_rhs(&mut self) {
match self {
AnyGenericVelocityConstraint::Nongrouped(c) => c.remove_bias_from_rhs(),
AnyGenericVelocityConstraint::NongroupedGround(c) => c.remove_bias_from_rhs(),
}
}
}
#[derive(Copy, Clone, Debug)]
pub(crate) struct GenericVelocityConstraint {
// We just build the generic constraint on top of the velocity constraint,
// adding some information we can use in the generic case.
pub velocity_constraint: VelocityConstraint,
pub j_id: usize,
pub ndofs1: usize,
pub ndofs2: usize,
pub generic_constraint_mask: u8,
}
impl GenericVelocityConstraint {
pub fn generate<Bodies>(
params: &IntegrationParameters,
manifold_id: ContactManifoldIndex,
manifold: &ContactManifold,
bodies: &Bodies,
multibodies: &MultibodyJointSet,
out_constraints: &mut Vec<AnyGenericVelocityConstraint>,
jacobians: &mut DVector<Real>,
jacobian_id: &mut usize,
push: bool,
) where
Bodies: ComponentSet<RigidBodyIds>
+ ComponentSet<RigidBodyVelocity>
+ ComponentSet<RigidBodyMassProps>
+ ComponentSet<RigidBodyType>,
{
let inv_dt = params.inv_dt();
let erp_inv_dt = params.erp_inv_dt();
let handle1 = manifold.data.rigid_body1.unwrap();
let handle2 = manifold.data.rigid_body2.unwrap();
let (rb_ids1, rb_vels1, rb_mprops1, rb_type1): (
&RigidBodyIds,
&RigidBodyVelocity,
&RigidBodyMassProps,
&RigidBodyType,
) = bodies.index_bundle(handle1.0);
let (rb_ids2, rb_vels2, rb_mprops2, rb_type2): (
&RigidBodyIds,
&RigidBodyVelocity,
&RigidBodyMassProps,
&RigidBodyType,
) = bodies.index_bundle(handle2.0);
let multibody1 = multibodies
.rigid_body_link(handle1)
.map(|m| (&multibodies[m.multibody], m.id));
let multibody2 = multibodies
.rigid_body_link(handle2)
.map(|m| (&multibodies[m.multibody], m.id));
let mj_lambda1 = multibody1
.map(|mb| mb.0.solver_id)
.unwrap_or(if rb_type1.is_dynamic() {
rb_ids1.active_set_offset
} else {
0
});
let mj_lambda2 = multibody2
.map(|mb| mb.0.solver_id)
.unwrap_or(if rb_type2.is_dynamic() {
rb_ids2.active_set_offset
} else {
0
});
let force_dir1 = -manifold.data.normal;
#[cfg(feature = "dim2")]
let tangents1 = force_dir1.orthonormal_basis();
#[cfg(feature = "dim3")]
let tangents1 = super::compute_tangent_contact_directions(
&force_dir1,
&rb_vels1.linvel,
&rb_vels2.linvel,
);
let multibodies_ndof = multibody1.map(|m| m.0.ndofs()).unwrap_or(0)
+ multibody2.map(|m| m.0.ndofs()).unwrap_or(0);
// For each solver contact we generate DIM constraints, and each constraints appends
// the multibodies jacobian and weighted jacobians
let required_jacobian_len =
*jacobian_id + manifold.data.solver_contacts.len() * multibodies_ndof * 2 * DIM;
if jacobians.nrows() < required_jacobian_len {
jacobians.resize_vertically_mut(required_jacobian_len, 0.0);
}
for (_l, manifold_points) in manifold
.data
.solver_contacts
.chunks(MAX_MANIFOLD_POINTS)
.enumerate()
{
let chunk_j_id = *jacobian_id;
let mut constraint = VelocityConstraint {
dir1: force_dir1,
#[cfg(feature = "dim3")]
tangent1: tangents1[0],
elements: [VelocityConstraintElement::zero(); MAX_MANIFOLD_POINTS],
im1: if rb_type1.is_dynamic() {
rb_mprops1.effective_inv_mass
} else {
na::zero()
},
im2: if rb_type2.is_dynamic() {
rb_mprops2.effective_inv_mass
} else {
na::zero()
},
limit: 0.0,
mj_lambda1,
mj_lambda2,
manifold_id,
manifold_contact_id: [0; MAX_MANIFOLD_POINTS],
num_contacts: manifold_points.len() as u8,
};
for k in 0..manifold_points.len() {
let manifold_point = &manifold_points[k];
let dp1 = manifold_point.point - rb_mprops1.world_com;
let dp2 = manifold_point.point - rb_mprops2.world_com;
let vel1 = rb_vels1.linvel + rb_vels1.angvel.gcross(dp1);
let vel2 = rb_vels2.linvel + rb_vels2.angvel.gcross(dp2);
constraint.limit = manifold_point.friction;
constraint.manifold_contact_id[k] = manifold_point.contact_id;
// Normal part.
{
let torque_dir1 = dp1.gcross(force_dir1);
let torque_dir2 = dp2.gcross(-force_dir1);
let gcross1 = if rb_type1.is_dynamic() {
rb_mprops1
.effective_world_inv_inertia_sqrt
.transform_vector(torque_dir1)
} else {
na::zero()
};
let gcross2 = if rb_type2.is_dynamic() {
rb_mprops2
.effective_world_inv_inertia_sqrt
.transform_vector(torque_dir2)
} else {
na::zero()
};
let inv_r1 = if let Some((mb1, link_id1)) = multibody1.as_ref() {
mb1.fill_jacobians(
*link_id1,
force_dir1,
#[cfg(feature = "dim2")]
na::vector!(torque_dir1),
#[cfg(feature = "dim3")]
torque_dir1,
jacobian_id,
jacobians,
)
.0
} else if rb_type1.is_dynamic() {
force_dir1.dot(&rb_mprops1.effective_inv_mass.component_mul(&force_dir1))
+ gcross1.gdot(gcross1)
} else {
0.0
};
let inv_r2 = if let Some((mb2, link_id2)) = multibody2.as_ref() {
mb2.fill_jacobians(
*link_id2,
-force_dir1,
#[cfg(feature = "dim2")]
na::vector!(torque_dir2),
#[cfg(feature = "dim3")]
torque_dir2,
jacobian_id,
jacobians,
)
.0
} else if rb_type2.is_dynamic() {
force_dir1.dot(&rb_mprops2.effective_inv_mass.component_mul(&force_dir1))
+ gcross2.gdot(gcross2)
} else {
0.0
};
let r = crate::utils::inv(inv_r1 + inv_r2);
let is_bouncy = manifold_point.is_bouncy() as u32 as Real;
let is_resting = 1.0 - is_bouncy;
let mut rhs_wo_bias = (1.0 + is_bouncy * manifold_point.restitution)
* (vel1 - vel2).dot(&force_dir1);
rhs_wo_bias += manifold_point.dist.max(0.0) * inv_dt;
rhs_wo_bias *= is_bouncy + is_resting * params.velocity_solve_fraction;
let rhs_bias =
/* is_resting * */ erp_inv_dt * manifold_point.dist.min(0.0);
constraint.elements[k].normal_part = VelocityConstraintNormalPart {
gcross1,
gcross2,
rhs: rhs_wo_bias + rhs_bias,
rhs_wo_bias,
impulse: na::zero(),
r,
};
}
// Tangent parts.
{
constraint.elements[k].tangent_part.impulse = na::zero();
for j in 0..DIM - 1 {
let torque_dir1 = dp1.gcross(tangents1[j]);
let gcross1 = if rb_type1.is_dynamic() {
rb_mprops1
.effective_world_inv_inertia_sqrt
.transform_vector(torque_dir1)
} else {
na::zero()
};
constraint.elements[k].tangent_part.gcross1[j] = gcross1;
let torque_dir2 = dp2.gcross(-tangents1[j]);
let gcross2 = if rb_type2.is_dynamic() {
rb_mprops2
.effective_world_inv_inertia_sqrt
.transform_vector(torque_dir2)
} else {
na::zero()
};
constraint.elements[k].tangent_part.gcross2[j] = gcross2;
let inv_r1 = if let Some((mb1, link_id1)) = multibody1.as_ref() {
mb1.fill_jacobians(
*link_id1,
tangents1[j],
#[cfg(feature = "dim2")]
na::vector![torque_dir1],
#[cfg(feature = "dim3")]
torque_dir1,
jacobian_id,
jacobians,
)
.0
} else if rb_type1.is_dynamic() {
force_dir1
.dot(&rb_mprops1.effective_inv_mass.component_mul(&force_dir1))
+ gcross1.gdot(gcross1)
} else {
0.0
};
let inv_r2 = if let Some((mb2, link_id2)) = multibody2.as_ref() {
mb2.fill_jacobians(
*link_id2,
-tangents1[j],
#[cfg(feature = "dim2")]
na::vector![torque_dir2],
#[cfg(feature = "dim3")]
torque_dir2,
jacobian_id,
jacobians,
)
.0
} else if rb_type2.is_dynamic() {
force_dir1
.dot(&rb_mprops2.effective_inv_mass.component_mul(&force_dir1))
+ gcross2.gdot(gcross2)
} else {
0.0
};
let r = crate::utils::inv(inv_r1 + inv_r2);
let rhs =
(vel1 - vel2 + manifold_point.tangent_velocity).dot(&tangents1[j]);
constraint.elements[k].tangent_part.rhs[j] = rhs;
// FIXME: in 3D, we should take into account gcross[0].dot(gcross[1])
// in lhs. See the corresponding code on the `velocity_constraint.rs`
// file.
constraint.elements[k].tangent_part.r[j] = r;
}
}
}
let ndofs1 = multibody1.map(|mb| mb.0.ndofs()).unwrap_or(0);
let ndofs2 = multibody2.map(|mb| mb.0.ndofs()).unwrap_or(0);
// NOTE: we use the generic constraint for non-dynamic bodies because this will
// reduce all ops to nothing because its ndofs will be zero.
let generic_constraint_mask = (multibody1.is_some() as u8)
| ((multibody2.is_some() as u8) << 1)
| (!rb_type1.is_dynamic() as u8)
| ((!rb_type2.is_dynamic() as u8) << 1);
let constraint = GenericVelocityConstraint {
velocity_constraint: constraint,
j_id: chunk_j_id,
ndofs1,
ndofs2,
generic_constraint_mask,
};
if push {
out_constraints.push(AnyGenericVelocityConstraint::Nongrouped(constraint));
} else {
out_constraints[manifold.data.constraint_index + _l] =
AnyGenericVelocityConstraint::Nongrouped(constraint);
}
}
}
pub fn solve(
&mut self,
cfm_factor: Real,
jacobians: &DVector<Real>,
mj_lambdas: &mut [DeltaVel<Real>],
generic_mj_lambdas: &mut DVector<Real>,
solve_restitution: bool,
solve_friction: bool,
) {
let mut mj_lambda1 = if self.generic_constraint_mask & 0b01 == 0 {
GenericRhs::DeltaVel(mj_lambdas[self.velocity_constraint.mj_lambda1 as usize])
} else {
GenericRhs::GenericId(self.velocity_constraint.mj_lambda1 as usize)
};
let mut mj_lambda2 = if self.generic_constraint_mask & 0b10 == 0 {
GenericRhs::DeltaVel(mj_lambdas[self.velocity_constraint.mj_lambda2 as usize])
} else {
GenericRhs::GenericId(self.velocity_constraint.mj_lambda2 as usize)
};
let elements = &mut self.velocity_constraint.elements
[..self.velocity_constraint.num_contacts as usize];
VelocityConstraintElement::generic_solve_group(
cfm_factor,
elements,
jacobians,
&self.velocity_constraint.dir1,
#[cfg(feature = "dim3")]
&self.velocity_constraint.tangent1,
&self.velocity_constraint.im1,
&self.velocity_constraint.im2,
self.velocity_constraint.limit,
self.ndofs1,
self.ndofs2,
self.j_id,
&mut mj_lambda1,
&mut mj_lambda2,
generic_mj_lambdas,
solve_restitution,
solve_friction,
);
if let GenericRhs::DeltaVel(mj_lambda1) = mj_lambda1 {
mj_lambdas[self.velocity_constraint.mj_lambda1 as usize] = mj_lambda1;
}
if let GenericRhs::DeltaVel(mj_lambda2) = mj_lambda2 {
mj_lambdas[self.velocity_constraint.mj_lambda2 as usize] = mj_lambda2;
}
}
pub fn writeback_impulses(&self, manifolds_all: &mut [&mut ContactManifold]) {
self.velocity_constraint.writeback_impulses(manifolds_all);
}
pub fn remove_bias_from_rhs(&mut self) {
self.velocity_constraint.remove_bias_from_rhs();
}
}