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Projection friction impulses on an implicit cone instead of a pyramidal approximation.

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This commit is contained in:
Crozet Sébastien
2021-03-07 11:43:47 +01:00
parent e7f805aea4
commit bed47a82e7
15 changed files with 618 additions and 218 deletions
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2
build/rapier3d-f64/Cargo.toml
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@@ -39,7 +39,7 @@ required-features = [ "dim3", "f64" ]
vec_map = { version = "0.8", optional = true }
instant = { version = "0.1", features = [ "now" ]}
num-traits = "0.2"
nalgebra = "0.25"
nalgebra = "^0.25.3"
parry3d-f64 = "0.2"
simba = "0.4"
approx = "0.4"

2
build/rapier3d/Cargo.toml
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@@ -39,7 +39,7 @@ required-features = [ "dim3", "f32" ]
vec_map = { version = "0.8", optional = true }
instant = { version = "0.1", features = [ "now" ]}
num-traits = "0.2"
nalgebra = "0.25"
nalgebra = "^0.25.3"
parry3d = "0.2"
simba = "0.4"
approx = "0.4"

2
examples2d/one_way_platforms2.rs
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@@ -40,7 +40,7 @@ impl PhysicsHooks for OneWayPlatformHook {
allowed_local_n1 = -Vector2::y();
} else if context.collider_handle2 == self.platform2 {
// Flip the allowed direction.
allowed_local_n1 = -Vector2::y();
allowed_local_n1 = Vector2::y();
}
// Call the helper function that simulates one-way platforms.

2
examples3d/all_examples3.rs
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@@ -19,6 +19,7 @@ mod debug_add_remove_collider3;
mod debug_boxes3;
mod debug_cylinder3;
mod debug_dynamic_collider_add3;
mod debug_friction3;
mod debug_infinite_fall3;
mod debug_rollback3;
mod debug_triangle3;
@@ -99,6 +100,7 @@ pub fn main() {
"(Debug) dyn. coll. add",
debug_dynamic_collider_add3::init_world,
),
("(Debug) friction", debug_friction3::init_world),
("(Debug) triangle", debug_triangle3::init_world),
("(Debug) trimesh", debug_trimesh3::init_world),
("(Debug) cylinder", debug_cylinder3::init_world),

50
examples3d/debug_friction3.rs Normal file
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@@ -0,0 +1,50 @@
use na::{Point3, Vector3};
use rapier3d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
use rapier3d::geometry::{ColliderBuilder, ColliderSet};
use rapier_testbed3d::Testbed;
pub fn init_world(testbed: &mut Testbed) {
/*
* World
*/
let mut bodies = RigidBodySet::new();
let mut colliders = ColliderSet::new();
let joints = JointSet::new();
/*
* Ground
*/
let ground_size = 100.0;
let ground_height = 0.1;
let rigid_body = RigidBodyBuilder::new_static().build();
let handle = bodies.insert(rigid_body);
let collider = ColliderBuilder::cuboid(ground_size, ground_height, ground_size)
.friction(1.5)
.build();
colliders.insert(collider, handle, &mut bodies);
// Build a dynamic box rigid body.
let rigid_body = RigidBodyBuilder::new_dynamic()
.translation(0.0, 1.1, 0.0)
.rotation(Vector3::y() * 0.3)
.build();
let handle = bodies.insert(rigid_body);
let collider = ColliderBuilder::cuboid(2.0, 1.0, 3.0).friction(1.5).build();
colliders.insert(collider, handle, &mut bodies);
let rigid_body = &mut bodies[handle];
let force = rigid_body.position() * Vector3::z() * 50.0;
rigid_body.set_linvel(force, true);
/*
* Set up the testbed.
*/
testbed.set_world(bodies, colliders, joints);
testbed.look_at(Point3::new(10.0, 10.0, 10.0), Point3::origin());
}
fn main() {
let testbed = Testbed::from_builders(0, vec![("Boxes", init_world)]);
testbed.run()
}

2
examples3d/one_way_platforms3.rs
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@@ -40,7 +40,7 @@ impl PhysicsHooks for OneWayPlatformHook {
allowed_local_n1 = -Vector3::y();
} else if context.collider_handle2 == self.platform2 {
// Flip the allowed direction.
allowed_local_n1 = -Vector3::y();
allowed_local_n1 = Vector3::y();
}
// Call the helper function that simulates one-way platforms.

2
src/dynamics/coefficient_combine_rule.rs
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@@ -25,7 +25,7 @@ impl CoefficientCombineRule {
let effective_rule = rule_value1.max(rule_value2);
match effective_rule {
0 => (coeff1 + coeff1) / 2.0,
0 => (coeff1 + coeff2) / 2.0,
1 => coeff1.min(coeff2),
2 => coeff1 * coeff2,
_ => coeff1.max(coeff2),

224
src/dynamics/solver/velocity_constraint.rs
View File

@@ -6,7 +6,8 @@ use crate::dynamics::{IntegrationParameters, RigidBodySet};
use crate::geometry::{ContactManifold, ContactManifoldIndex};
use crate::math::{AngVector, Real, Vector, DIM, MAX_MANIFOLD_POINTS};
use crate::utils::{WAngularInertia, WBasis, WCross, WDot};
use simba::simd::SimdPartialOrd;
#[cfg(feature = "dim2")]
use na::SimdPartialOrd;
//#[repr(align(64))]
#[derive(Copy, Clone, Debug)]
@@ -78,7 +79,34 @@ impl AnyVelocityConstraint {
}
#[derive(Copy, Clone, Debug)]
pub(crate) struct VelocityConstraintElementPart {
pub(crate) struct VelocityConstraintTangentPart {
pub gcross1: [AngVector<Real>; DIM - 1],
pub gcross2: [AngVector<Real>; DIM - 1],
pub rhs: [Real; DIM - 1],
#[cfg(feature = "dim2")]
pub impulse: [Real; DIM - 1],
#[cfg(feature = "dim3")]
pub impulse: na::Vector2<Real>,
pub r: [Real; DIM - 1],
}
impl VelocityConstraintTangentPart {
fn zero() -> Self {
Self {
gcross1: [na::zero(); DIM - 1],
gcross2: [na::zero(); DIM - 1],
rhs: [0.0; DIM - 1],
#[cfg(feature = "dim2")]
impulse: [0.0; DIM - 1],
#[cfg(feature = "dim3")]
impulse: na::zero(),
r: [0.0; DIM - 1],
}
}
}
#[derive(Copy, Clone, Debug)]
pub(crate) struct VelocityConstraintNormalPart {
pub gcross1: AngVector<Real>,
pub gcross2: AngVector<Real>,
pub rhs: Real,
@@ -87,7 +115,7 @@ pub(crate) struct VelocityConstraintElementPart {
}
#[cfg(not(target_arch = "wasm32"))]
impl VelocityConstraintElementPart {
impl VelocityConstraintNormalPart {
fn zero() -> Self {
Self {
gcross1: na::zero(),
@@ -101,16 +129,16 @@ impl VelocityConstraintElementPart {
#[derive(Copy, Clone, Debug)]
pub(crate) struct VelocityConstraintElement {
pub normal_part: VelocityConstraintElementPart,
pub tangent_part: [VelocityConstraintElementPart; DIM - 1],
pub normal_part: VelocityConstraintNormalPart,
pub tangent_part: VelocityConstraintTangentPart,
}
#[cfg(not(target_arch = "wasm32"))]
impl VelocityConstraintElement {
pub fn zero() -> Self {
Self {
normal_part: VelocityConstraintElementPart::zero(),
tangent_part: [VelocityConstraintElementPart::zero(); DIM - 1],
normal_part: VelocityConstraintNormalPart::zero(),
tangent_part: VelocityConstraintTangentPart::zero(),
}
}
}
@@ -118,6 +146,10 @@ impl VelocityConstraintElement {
#[derive(Copy, Clone, Debug)]
pub(crate) struct VelocityConstraint {
pub dir1: Vector<Real>, // Non-penetration force direction for the first body.
#[cfg(feature = "dim3")]
pub tangent1: Vector<Real>, // One of the friction force directions.
#[cfg(feature = "dim3")]
pub tangent_rot1: na::UnitComplex<Real>, // Orientation of the tangent basis wrt. the reference basis.
pub im1: Real,
pub im2: Real,
pub limit: Real,
@@ -156,6 +188,12 @@ impl VelocityConstraint {
let force_dir1 = -manifold.data.normal;
let warmstart_coeff = manifold.data.warmstart_multiplier * params.warmstart_coeff;
#[cfg(feature = "dim2")]
let tangents1 = force_dir1.orthonormal_basis();
#[cfg(feature = "dim3")]
let (tangents1, tangent_rot1) =
super::compute_tangent_contact_directions(&force_dir1, &rb1.linvel, &rb2.linvel);
for (_l, manifold_points) in manifold
.data
.solver_contacts
@@ -165,6 +203,10 @@ impl VelocityConstraint {
#[cfg(not(target_arch = "wasm32"))]
let mut constraint = VelocityConstraint {
dir1: force_dir1,
#[cfg(feature = "dim3")]
tangent1: tangents1[0],
#[cfg(feature = "dim3")]
tangent_rot1,
elements: [VelocityConstraintElement::zero(); MAX_MANIFOLD_POINTS],
im1: rb1.effective_inv_mass,
im2: rb2.effective_inv_mass,
@@ -203,7 +245,7 @@ impl VelocityConstraint {
.as_nongrouped_mut()
.unwrap()
} else {
unreachable!(); // We don't have parallelization on WASM yet, so this is unreachable.
unreachable!(); // We don't have parallelization on WASM yet, so this is unreachable.
};
#[cfg(target_arch = "wasm32")]
@@ -254,7 +296,7 @@ impl VelocityConstraint {
rhs *= is_bouncy + is_resting * params.velocity_solve_fraction;
rhs += is_resting * velocity_based_erp_inv_dt * manifold_point.dist.min(0.0);
constraint.elements[k].normal_part = VelocityConstraintElementPart {
constraint.elements[k].normal_part = VelocityConstraintNormalPart {
gcross1,
gcross2,
rhs,
@@ -265,7 +307,12 @@ impl VelocityConstraint {
// Tangent parts.
{
let tangents1 = force_dir1.orthonormal_basis();
#[cfg(feature = "dim3")]
let impulse =
tangent_rot1 * manifold_points[k].data.tangent_impulse * warmstart_coeff;
#[cfg(feature = "dim2")]
let impulse = [manifold_points[k].data.tangent_impulse * warmstart_coeff];
constraint.elements[k].tangent_part.impulse = impulse;
for j in 0..DIM - 1 {
let gcross1 = rb1
@@ -281,18 +328,11 @@ impl VelocityConstraint {
+ gcross2.gdot(gcross2));
let rhs =
(vel1 - vel2 + manifold_point.tangent_velocity).dot(&tangents1[j]);
#[cfg(feature = "dim2")]
let impulse = manifold_point.data.tangent_impulse * warmstart_coeff;
#[cfg(feature = "dim3")]
let impulse = manifold_point.data.tangent_impulse[j] * warmstart_coeff;
constraint.elements[k].tangent_part[j] = VelocityConstraintElementPart {
gcross1,
gcross2,
rhs,
impulse,
r,
};
constraint.elements[k].tangent_part.gcross1[j] = gcross1;
constraint.elements[k].tangent_part.gcross2[j] = gcross2;
constraint.elements[k].tangent_part.rhs[j] = rhs;
constraint.elements[k].tangent_part.r[j] = r;
}
}
}
@@ -311,6 +351,11 @@ impl VelocityConstraint {
let mut mj_lambda1 = DeltaVel::zero();
let mut mj_lambda2 = DeltaVel::zero();
#[cfg(feature = "dim3")]
let tangents1 = [self.tangent1, self.dir1.cross(&self.tangent1)];
#[cfg(feature = "dim2")]
let tangents1 = self.dir1.orthonormal_basis();
for i in 0..self.num_contacts as usize {
let elt = &self.elements[i].normal_part;
mj_lambda1.linear += self.dir1 * (self.im1 * elt.impulse);
@@ -319,16 +364,13 @@ impl VelocityConstraint {
mj_lambda2.linear += self.dir1 * (-self.im2 * elt.impulse);
mj_lambda2.angular += elt.gcross2 * elt.impulse;
// FIXME: move this out of the for loop?
let tangents1 = self.dir1.orthonormal_basis();
for j in 0..DIM - 1 {
let elt = &self.elements[i].tangent_part[j];
mj_lambda1.linear += tangents1[j] * (self.im1 * elt.impulse);
mj_lambda1.angular += elt.gcross1 * elt.impulse;
let elt = &self.elements[i].tangent_part;
mj_lambda1.linear += tangents1[j] * (self.im1 * elt.impulse[j]);
mj_lambda1.angular += elt.gcross1[j] * elt.impulse[j];
mj_lambda2.linear += tangents1[j] * (-self.im2 * elt.impulse);
mj_lambda2.angular += elt.gcross2 * elt.impulse;
mj_lambda2.linear += tangents1[j] * (-self.im2 * elt.impulse[j]);
mj_lambda2.angular += elt.gcross2[j] * elt.impulse[j];
}
}
@@ -343,28 +385,63 @@ impl VelocityConstraint {
let mut mj_lambda2 = mj_lambdas[self.mj_lambda2 as usize];
// Solve friction.
#[cfg(feature = "dim3")]
let bitangent1 = self.dir1.cross(&self.tangent1);
#[cfg(feature = "dim2")]
let tangents1 = self.dir1.orthonormal_basis();
#[cfg(feature = "dim2")]
for i in 0..self.num_contacts as usize {
let tangents1 = self.dir1.orthonormal_basis();
let normal_elt = &self.elements[i].normal_part;
let elt = &mut self.elements[i].tangent_part;
let dimpulse = tangents1[0].dot(&mj_lambda1.linear)
+ elt.gcross1[0].gdot(mj_lambda1.angular)
- tangents1[0].dot(&mj_lambda2.linear)
+ elt.gcross2[0].gdot(mj_lambda2.angular)
+ elt.rhs[0];
let limit = self.limit * normal_elt.impulse;
let new_impulse = (elt.impulse[0] - elt.r[0] * dimpulse).simd_clamp(-limit, limit);
let dlambda = new_impulse - elt.impulse[0];
elt.impulse[0] = new_impulse;
for j in 0..DIM - 1 {
let normal_elt = &self.elements[i].normal_part;
let elt = &mut self.elements[i].tangent_part[j];
let dimpulse = tangents1[j].dot(&mj_lambda1.linear)
+ elt.gcross1.gdot(mj_lambda1.angular)
- tangents1[j].dot(&mj_lambda2.linear)
+ elt.gcross2.gdot(mj_lambda2.angular)
+ elt.rhs;
let limit = self.limit * normal_elt.impulse;
let new_impulse = (elt.impulse - elt.r * dimpulse).simd_clamp(-limit, limit);
let dlambda = new_impulse - elt.impulse;
elt.impulse = new_impulse;
mj_lambda1.linear += tangents1[0] * (self.im1 * dlambda);
mj_lambda1.angular += elt.gcross1[0] * dlambda;
mj_lambda1.linear += tangents1[j] * (self.im1 * dlambda);
mj_lambda1.angular += elt.gcross1 * dlambda;
mj_lambda2.linear += tangents1[0] * (-self.im2 * dlambda);
mj_lambda2.angular += elt.gcross2[0] * dlambda;
}
mj_lambda2.linear += tangents1[j] * (-self.im2 * dlambda);
mj_lambda2.angular += elt.gcross2 * dlambda;
}
#[cfg(feature = "dim3")]
for i in 0..self.num_contacts as usize {
let limit = self.limit * self.elements[i].normal_part.impulse;
let elt = &mut self.elements[i].tangent_part;
let dimpulse_0 = self.tangent1.dot(&mj_lambda1.linear)
+ elt.gcross1[0].gdot(mj_lambda1.angular)
- self.tangent1.dot(&mj_lambda2.linear)
+ elt.gcross2[0].gdot(mj_lambda2.angular)
+ elt.rhs[0];
let dimpulse_1 = bitangent1.dot(&mj_lambda1.linear)
+ elt.gcross1[1].gdot(mj_lambda1.angular)
- bitangent1.dot(&mj_lambda2.linear)
+ elt.gcross2[1].gdot(mj_lambda2.angular)
+ elt.rhs[1];
let new_impulse = na::Vector2::new(
elt.impulse[0] - elt.r[0] * dimpulse_0,
elt.impulse[1] - elt.r[1] * dimpulse_1,
);
let new_impulse = new_impulse.cap_magnitude(limit);
let dlambda = new_impulse - elt.impulse;
elt.impulse = new_impulse;
mj_lambda1.linear +=
self.tangent1 * (self.im1 * dlambda[0]) + bitangent1 * (self.im1 * dlambda[1]);
mj_lambda1.angular += elt.gcross1[0] * dlambda[0] + elt.gcross1[1] * dlambda[1];
mj_lambda2.linear +=
self.tangent1 * (-self.im2 * dlambda[0]) + bitangent1 * (-self.im2 * dlambda[1]);
mj_lambda2.angular += elt.gcross2[0] * dlambda[0] + elt.gcross2[1] * dlambda[1];
}
// Solve non-penetration.
@@ -398,15 +475,58 @@ impl VelocityConstraint {
active_contact.data.impulse = self.elements[k].normal_part.impulse;
#[cfg(feature = "dim2")]
{
active_contact.data.tangent_impulse = self.elements[k].tangent_part[0].impulse;
active_contact.data.tangent_impulse = self.elements[k].tangent_part.impulse[0];
}
#[cfg(feature = "dim3")]
{
active_contact.data.tangent_impulse = [
self.elements[k].tangent_part[0].impulse,
self.elements[k].tangent_part[1].impulse,
];
active_contact.data.tangent_impulse = self
.tangent_rot1
.inverse_transform_vector(&self.elements[k].tangent_part.impulse);
}
}
}
}
#[inline(always)]
#[cfg(feature = "dim3")]
pub(crate) fn compute_tangent_contact_directions<N>(
force_dir1: &Vector<N>,
linvel1: &Vector<N>,
linvel2: &Vector<N>,
) -> ([Vector<N>; DIM - 1], na::UnitComplex<N>)
where
N: na::SimdRealField,
N::Element: na::RealField,
Vector<N>: WBasis,
{
use na::SimdValue;
// Compute the tangent direction. Pick the direction of
// the linear relative velocity, if it is not too small.
// Otherwise use a fallback direction.
let relative_linvel = linvel1 - linvel2;
let mut tangent_relative_linvel =
relative_linvel - force_dir1 * (force_dir1.dot(&relative_linvel));
let tangent_linvel_norm = tangent_relative_linvel.normalize_mut();
let threshold: N::Element = na::convert(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);
// Rotation such that: rot * tangent_fallback = tangent1
// (when projected in the tangent plane.) This is needed to ensure the
// warmstart impulse has the correct orientation. Indeed, at frame n + 1,
// we need to reapply the same impulse as we did in frame n. However the
// basis on which the tangent impulse is expresses may change at each frame
// (because the the relative linvel may change direction at each frame).
// So we need this rotation to:
// - Project the impulse back to the "reference" basis at after friction is resolved.
// - Project the old impulse on the new basis before the friction is resolved.
let rot = na::UnitComplex::new_unchecked(na::Complex::new(
tangent1.dot(&tangent_fallback),
bitangent1.dot(&tangent_fallback),
));
([tangent1, bitangent1], rot)
}

195
src/dynamics/solver/velocity_constraint_wide.rs
View File

@@ -4,12 +4,41 @@ use crate::geometry::{ContactManifold, ContactManifoldIndex};
use crate::math::{
AngVector, AngularInertia, Point, Real, SimdReal, Vector, DIM, MAX_MANIFOLD_POINTS, SIMD_WIDTH,
};
use crate::utils::{WAngularInertia, WBasis, WCross, WDot};
#[cfg(feature = "dim2")]
use crate::utils::WBasis;
use crate::utils::{WAngularInertia, WCross, WDot};
use num::Zero;
use simba::simd::{SimdPartialOrd, SimdValue};
#[derive(Copy, Clone, Debug)]
pub(crate) struct WVelocityConstraintElementPart {
pub(crate) struct WVelocityConstraintTangentPart {
pub gcross1: [AngVector<SimdReal>; DIM - 1],
pub gcross2: [AngVector<SimdReal>; DIM - 1],
pub rhs: [SimdReal; DIM - 1],
#[cfg(feature = "dim2")]
pub impulse: [SimdReal; DIM - 1],
#[cfg(feature = "dim3")]
pub impulse: na::Vector2<SimdReal>,
pub r: [SimdReal; DIM - 1],
}
impl WVelocityConstraintTangentPart {
pub fn zero() -> Self {
Self {
gcross1: [AngVector::zero(); DIM - 1],
gcross2: [AngVector::zero(); DIM - 1],
rhs: [SimdReal::zero(); DIM - 1],
#[cfg(feature = "dim2")]
impulse: [SimdReal::zero(); DIM - 1],
#[cfg(feature = "dim3")]
impulse: na::Vector2::zeros(),
r: [SimdReal::zero(); DIM - 1],
}
}
}
#[derive(Copy, Clone, Debug)]
pub(crate) struct WVelocityConstraintNormalPart {
pub gcross1: AngVector<SimdReal>,
pub gcross2: AngVector<SimdReal>,
pub rhs: SimdReal,
@@ -17,7 +46,7 @@ pub(crate) struct WVelocityConstraintElementPart {
pub r: SimdReal,
}
impl WVelocityConstraintElementPart {
impl WVelocityConstraintNormalPart {
pub fn zero() -> Self {
Self {
gcross1: AngVector::zero(),
@@ -31,15 +60,15 @@ impl WVelocityConstraintElementPart {
#[derive(Copy, Clone, Debug)]
pub(crate) struct WVelocityConstraintElement {
pub normal_part: WVelocityConstraintElementPart,
pub tangent_parts: [WVelocityConstraintElementPart; DIM - 1],
pub normal_part: WVelocityConstraintNormalPart,
pub tangent_part: WVelocityConstraintTangentPart,
}
impl WVelocityConstraintElement {
pub fn zero() -> Self {
Self {
normal_part: WVelocityConstraintElementPart::zero(),
tangent_parts: [WVelocityConstraintElementPart::zero(); DIM - 1],
normal_part: WVelocityConstraintNormalPart::zero(),
tangent_part: WVelocityConstraintTangentPart::zero(),
}
}
}
@@ -47,6 +76,10 @@ impl WVelocityConstraintElement {
#[derive(Copy, Clone, Debug)]
pub(crate) struct WVelocityConstraint {
pub dir1: Vector<SimdReal>, // Non-penetration force direction for the first body.
#[cfg(feature = "dim3")]
pub tangent1: Vector<SimdReal>, // One of the friction force directions.
#[cfg(feature = "dim3")]
pub tangent_rot1: na::UnitComplex<SimdReal>, // Orientation of the tangent basis wrt. the reference basis.
pub elements: [WVelocityConstraintElement; MAX_MANIFOLD_POINTS],
pub num_contacts: u8,
pub im1: SimdReal,
@@ -108,6 +141,12 @@ impl WVelocityConstraint {
let warmstart_coeff = warmstart_multiplier * SimdReal::splat(params.warmstart_coeff);
let num_active_contacts = manifolds[0].data.num_active_contacts();
#[cfg(feature = "dim2")]
let tangents1 = force_dir1.orthonormal_basis();
#[cfg(feature = "dim3")]
let (tangents1, tangent_rot1) =
super::compute_tangent_contact_directions(&force_dir1, &linvel1, &linvel2);
for l in (0..num_active_contacts).step_by(MAX_MANIFOLD_POINTS) {
let manifold_points = array![|ii|
&manifolds[ii].data.solver_contacts[l..num_active_contacts]; SIMD_WIDTH
@@ -116,6 +155,10 @@ impl WVelocityConstraint {
let mut constraint = WVelocityConstraint {
dir1: force_dir1,
#[cfg(feature = "dim3")]
tangent1: tangents1[0],
#[cfg(feature = "dim3")]
tangent_rot1,
elements: [WVelocityConstraintElement::zero(); MAX_MANIFOLD_POINTS],
im1,
im2,
@@ -169,7 +212,7 @@ impl WVelocityConstraint {
rhs +=
dist.simd_min(SimdReal::zero()) * (velocity_based_erp_inv_dt * is_resting);
constraint.elements[k].normal_part = WVelocityConstraintElementPart {
constraint.elements[k].normal_part = WVelocityConstraintNormalPart {
gcross1,
gcross2,
rhs,
@@ -179,31 +222,30 @@ impl WVelocityConstraint {
}
// tangent parts.
let tangents1 = force_dir1.orthonormal_basis();
#[cfg(feature = "dim2")]
let impulse = [SimdReal::from(
array![|ii| manifold_points[ii][k].data.tangent_impulse; SIMD_WIDTH],
)];
for j in 0..DIM - 1 {
#[cfg(feature = "dim2")]
let impulse = SimdReal::from(
#[cfg(feature = "dim3")]
let impulse = tangent_rot1
* na::Vector2::from(
array![|ii| manifold_points[ii][k].data.tangent_impulse; SIMD_WIDTH],
);
#[cfg(feature = "dim3")]
let impulse = SimdReal::from(
array![|ii| manifold_points[ii][k].data.tangent_impulse[j]; SIMD_WIDTH],
);
constraint.elements[k].tangent_part.impulse = impulse;
for j in 0..DIM - 1 {
let gcross1 = ii1.transform_vector(dp1.gcross(tangents1[j]));
let gcross2 = ii2.transform_vector(dp2.gcross(-tangents1[j]));
let r = SimdReal::splat(1.0)
/ (im1 + im2 + gcross1.gdot(gcross1) + gcross2.gdot(gcross2));
let rhs = (vel1 - vel2 + tangent_velocity).dot(&tangents1[j]);
constraint.elements[k].tangent_parts[j] = WVelocityConstraintElementPart {
gcross1,
gcross2,
rhs,
impulse: impulse * warmstart_coeff,
r,
};
constraint.elements[k].tangent_part.gcross1[j] = gcross1;
constraint.elements[k].tangent_part.gcross2[j] = gcross2;
constraint.elements[k].tangent_part.rhs[j] = rhs;
constraint.elements[k].tangent_part.r[j] = r;
}
}
@@ -235,6 +277,11 @@ impl WVelocityConstraint {
),
};
#[cfg(feature = "dim3")]
let tangents1 = [self.tangent1, self.dir1.cross(&self.tangent1)];
#[cfg(feature = "dim2")]
let tangents1 = self.dir1.orthonormal_basis();
for i in 0..self.num_contacts as usize {
let elt = &self.elements[i].normal_part;
mj_lambda1.linear += self.dir1 * (self.im1 * elt.impulse);
@@ -243,16 +290,13 @@ impl WVelocityConstraint {
mj_lambda2.linear += self.dir1 * (-self.im2 * elt.impulse);
mj_lambda2.angular += elt.gcross2 * elt.impulse;
// FIXME: move this out of the for loop?
let tangents1 = self.dir1.orthonormal_basis();
for j in 0..DIM - 1 {
let elt = &self.elements[i].tangent_parts[j];
mj_lambda1.linear += tangents1[j] * (self.im1 * elt.impulse);
mj_lambda1.angular += elt.gcross1 * elt.impulse;
let elt = &self.elements[i].tangent_part;
mj_lambda1.linear += tangents1[j] * (self.im1 * elt.impulse[j]);
mj_lambda1.angular += elt.gcross1[j] * elt.impulse[j];
mj_lambda2.linear += tangents1[j] * (-self.im2 * elt.impulse);
mj_lambda2.angular += elt.gcross2 * elt.impulse;
mj_lambda2.linear += tangents1[j] * (-self.im2 * elt.impulse[j]);
mj_lambda2.angular += elt.gcross2[j] * elt.impulse[j];
}
}
@@ -278,36 +322,71 @@ impl WVelocityConstraint {
let mut mj_lambda2 = DeltaVel {
linear: Vector::from(
array![ |ii| mj_lambdas[ self.mj_lambda2[ii] as usize].linear; SIMD_WIDTH],
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],
array![|ii| mj_lambdas[ self.mj_lambda2[ii] as usize].angular; SIMD_WIDTH],
),
};
// Solve friction first.
// Solve friction.
#[cfg(feature = "dim3")]
let bitangent1 = self.dir1.cross(&self.tangent1);
#[cfg(feature = "dim2")]
let tangents1 = self.dir1.orthonormal_basis();
#[cfg(feature = "dim2")]
for i in 0..self.num_contacts as usize {
// FIXME: move this out of the for loop?
let tangents1 = self.dir1.orthonormal_basis();
let normal_elt = &self.elements[i].normal_part;
for j in 0..DIM - 1 {
let elt = &mut self.elements[i].tangent_parts[j];
let dimpulse = tangents1[j].dot(&mj_lambda1.linear)
+ elt.gcross1.gdot(mj_lambda1.angular)
- tangents1[j].dot(&mj_lambda2.linear)
+ elt.gcross2.gdot(mj_lambda2.angular)
+ elt.rhs;
let limit = self.limit * normal_elt.impulse;
let new_impulse = (elt.impulse - elt.r * dimpulse).simd_clamp(-limit, limit);
let dlambda = new_impulse - elt.impulse;
elt.impulse = new_impulse;
let elt = &mut self.elements[i].tangent_part;
let dimpulse = tangents1[0].dot(&mj_lambda1.linear)
+ elt.gcross1[0].gdot(mj_lambda1.angular)
- tangents1[0].dot(&mj_lambda2.linear)
+ elt.gcross2[0].gdot(mj_lambda2.angular)
+ elt.rhs[0];
let limit = self.limit * normal_elt.impulse;
let new_impulse = (elt.impulse[0] - elt.r[0] * dimpulse).simd_clamp(-limit, limit);
let dlambda = new_impulse - elt.impulse[0];
elt.impulse[0] = new_impulse;
mj_lambda1.linear += tangents1[j] * (self.im1 * dlambda);
mj_lambda1.angular += elt.gcross1 * dlambda;
mj_lambda2.linear += tangents1[j] * (-self.im2 * dlambda);
mj_lambda2.angular += elt.gcross2 * dlambda;
}
mj_lambda1.linear += tangents1[0] * (self.im1 * dlambda);
mj_lambda1.angular += elt.gcross1[0] * dlambda;
mj_lambda2.linear += tangents1[0] * (-self.im2 * dlambda);
mj_lambda2.angular += elt.gcross2[0] * dlambda;
}
#[cfg(feature = "dim3")]
for i in 0..self.num_contacts as usize {
let limit = self.limit * self.elements[i].normal_part.impulse;
let elts = &mut self.elements[i].tangent_part;
let dimpulse_0 = self.tangent1.dot(&mj_lambda1.linear)
+ elts.gcross1[0].gdot(mj_lambda1.angular)
- self.tangent1.dot(&mj_lambda2.linear)
+ elts.gcross2[0].gdot(mj_lambda2.angular)
+ elts.rhs[0];
let dimpulse_1 = bitangent1.dot(&mj_lambda1.linear)
+ elts.gcross1[1].gdot(mj_lambda1.angular)
- bitangent1.dot(&mj_lambda2.linear)
+ elts.gcross2[1].gdot(mj_lambda2.angular)
+ elts.rhs[1];
let new_impulse = na::Vector2::new(
elts.impulse[0] - elts.r[0] * dimpulse_0,
elts.impulse[1] - elts.r[1] * dimpulse_1,
);
let new_impulse = new_impulse.simd_cap_magnitude(limit);
let dlambda = new_impulse - elts.impulse;
elts.impulse = new_impulse;
mj_lambda1.linear +=
self.tangent1 * (self.im1 * dlambda[0]) + bitangent1 * (self.im1 * dlambda[1]);
mj_lambda1.angular += elts.gcross1[0] * dlambda[0] + elts.gcross1[1] * dlambda[1];
mj_lambda2.linear +=
self.tangent1 * (-self.im2 * dlambda[0]) + bitangent1 * (-self.im2 * dlambda[1]);
mj_lambda2.angular += elts.gcross2[0] * dlambda[0] + elts.gcross2[1] * dlambda[1];
}
// Solve non-penetration after friction.
@@ -340,11 +419,12 @@ impl WVelocityConstraint {
pub fn writeback_impulses(&self, manifolds_all: &mut [&mut ContactManifold]) {
for k in 0..self.num_contacts as usize {
let impulses: [_; SIMD_WIDTH] = self.elements[k].normal_part.impulse.into();
let tangent_impulses: [_; SIMD_WIDTH] =
self.elements[k].tangent_parts[0].impulse.into();
#[cfg(feature = "dim2")]
let tangent_impulses: [_; SIMD_WIDTH] = self.elements[k].tangent_part.impulse[0].into();
#[cfg(feature = "dim3")]
let bitangent_impulses: [_; SIMD_WIDTH] =
self.elements[k].tangent_parts[1].impulse.into();
let tangent_impulses = self
.tangent_rot1
.inverse_transform_vector(&self.elements[k].tangent_part.impulse);
for ii in 0..SIMD_WIDTH {
let manifold = &mut manifolds_all[self.manifold_id[ii]];
@@ -358,8 +438,7 @@ impl WVelocityConstraint {
}
#[cfg(feature = "dim3")]
{
active_contact.data.tangent_impulse =
[tangent_impulses[ii], bitangent_impulses[ii]];
active_contact.data.tangent_impulse = tangent_impulses.extract(ii);
}
}
}

154
src/dynamics/solver/velocity_ground_constraint.rs
View File

@@ -1,13 +1,42 @@
use super::{AnyVelocityConstraint, DeltaVel};
use crate::math::{AngVector, Real, Vector, DIM, MAX_MANIFOLD_POINTS};
use crate::utils::{WAngularInertia, WBasis, WCross, WDot};
#[cfg(feature = "dim2")]
use crate::utils::WBasis;
use crate::utils::{WAngularInertia, WCross, WDot};
use crate::dynamics::{IntegrationParameters, RigidBodySet};
use crate::geometry::{ContactManifold, ContactManifoldIndex};
use simba::simd::SimdPartialOrd;
#[cfg(feature = "dim2")]
use na::SimdPartialOrd;
#[derive(Copy, Clone, Debug)]
pub(crate) struct VelocityGroundConstraintElementPart {
pub(crate) struct VelocityGroundConstraintTangentPart {
pub gcross2: [AngVector<Real>; DIM - 1],
pub rhs: [Real; DIM - 1],
#[cfg(feature = "dim2")]
pub impulse: [Real; DIM - 1],
#[cfg(feature = "dim3")]
pub impulse: na::Vector2<Real>,
pub r: [Real; DIM - 1],
}
#[cfg(not(target_arch = "wasm32"))]
impl VelocityGroundConstraintTangentPart {
fn zero() -> Self {
Self {
gcross2: [na::zero(); DIM - 1],
rhs: [0.0; DIM - 1],
#[cfg(feature = "dim2")]
impulse: [0.0; DIM - 1],
#[cfg(feature = "dim3")]
impulse: na::zero(),
r: [0.0; DIM - 1],
}
}
}
#[derive(Copy, Clone, Debug)]
pub(crate) struct VelocityGroundConstraintNormalPart {
pub gcross2: AngVector<Real>,
pub rhs: Real,
pub impulse: Real,
@@ -15,7 +44,7 @@ pub(crate) struct VelocityGroundConstraintElementPart {
}
#[cfg(not(target_arch = "wasm32"))]
impl VelocityGroundConstraintElementPart {
impl VelocityGroundConstraintNormalPart {
fn zero() -> Self {
Self {
gcross2: na::zero(),
@@ -28,16 +57,16 @@ impl VelocityGroundConstraintElementPart {
#[derive(Copy, Clone, Debug)]
pub(crate) struct VelocityGroundConstraintElement {
pub normal_part: VelocityGroundConstraintElementPart,
pub tangent_part: [VelocityGroundConstraintElementPart; DIM - 1],
pub normal_part: VelocityGroundConstraintNormalPart,
pub tangent_part: VelocityGroundConstraintTangentPart,
}
#[cfg(not(target_arch = "wasm32"))]
impl VelocityGroundConstraintElement {
pub fn zero() -> Self {
Self {
normal_part: VelocityGroundConstraintElementPart::zero(),
tangent_part: [VelocityGroundConstraintElementPart::zero(); DIM - 1],
normal_part: VelocityGroundConstraintNormalPart::zero(),
tangent_part: VelocityGroundConstraintTangentPart::zero(),
}
}
}
@@ -45,6 +74,10 @@ impl VelocityGroundConstraintElement {
#[derive(Copy, Clone, Debug)]
pub(crate) struct VelocityGroundConstraint {
pub dir1: Vector<Real>, // Non-penetration force direction for the first body.
#[cfg(feature = "dim3")]
pub tangent1: Vector<Real>, // One of the friction force directions.
#[cfg(feature = "dim3")]
pub tangent_rot1: na::UnitComplex<Real>, // Orientation of the tangent basis wrt. the reference basis.
pub im2: Real,
pub limit: Real,
pub mj_lambda2: usize,
@@ -77,6 +110,12 @@ impl VelocityGroundConstraint {
(-manifold.data.normal, 1.0)
};
#[cfg(feature = "dim2")]
let tangents1 = force_dir1.orthonormal_basis();
#[cfg(feature = "dim3")]
let (tangents1, tangent_rot1) =
super::compute_tangent_contact_directions(&force_dir1, &rb1.linvel, &rb2.linvel);
let mj_lambda2 = rb2.active_set_offset;
let warmstart_coeff = manifold.data.warmstart_multiplier * params.warmstart_coeff;
@@ -89,6 +128,10 @@ impl VelocityGroundConstraint {
#[cfg(not(target_arch = "wasm32"))]
let mut constraint = VelocityGroundConstraint {
dir1: force_dir1,
#[cfg(feature = "dim3")]
tangent1: tangents1[0],
#[cfg(feature = "dim3")]
tangent_rot1,
elements: [VelocityGroundConstraintElement::zero(); MAX_MANIFOLD_POINTS],
im2: rb2.effective_inv_mass,
limit: 0.0,
@@ -166,7 +209,7 @@ impl VelocityGroundConstraint {
rhs *= is_bouncy + is_resting * params.velocity_solve_fraction;
rhs += is_resting * velocity_based_erp_inv_dt * manifold_point.dist.min(0.0);
constraint.elements[k].normal_part = VelocityGroundConstraintElementPart {
constraint.elements[k].normal_part = VelocityGroundConstraintNormalPart {
gcross2,
rhs,
impulse: manifold_point.data.impulse * warmstart_coeff,
@@ -176,7 +219,12 @@ impl VelocityGroundConstraint {
// Tangent parts.
{
let tangents1 = force_dir1.orthonormal_basis();
#[cfg(feature = "dim3")]
let impulse =
tangent_rot1 * manifold_points[k].data.tangent_impulse * warmstart_coeff;
#[cfg(feature = "dim2")]
let impulse = [manifold_points[k].data.tangent_impulse * warmstart_coeff];
constraint.elements[k].tangent_part.impulse = impulse;
for j in 0..DIM - 1 {
let gcross2 = rb2
@@ -186,18 +234,10 @@ impl VelocityGroundConstraint {
let rhs = (vel1 - vel2
+ flipped_multiplier * manifold_point.tangent_velocity)
.dot(&tangents1[j]);
#[cfg(feature = "dim2")]
let impulse = manifold_points[k].data.tangent_impulse * warmstart_coeff;
#[cfg(feature = "dim3")]
let impulse = manifold_points[k].data.tangent_impulse[j] * warmstart_coeff;
constraint.elements[k].tangent_part[j] =
VelocityGroundConstraintElementPart {
gcross2,
rhs,
impulse,
r,
};
constraint.elements[k].tangent_part.gcross2[j] = gcross2;
constraint.elements[k].tangent_part.rhs[j] = rhs;
constraint.elements[k].tangent_part.r[j] = r;
}
}
}
@@ -214,6 +254,9 @@ impl VelocityGroundConstraint {
pub fn warmstart(&self, mj_lambdas: &mut [DeltaVel<Real>]) {
let mut mj_lambda2 = DeltaVel::zero();
#[cfg(feature = "dim3")]
let tangents1 = [self.tangent1, self.dir1.cross(&self.tangent1)];
#[cfg(feature = "dim2")]
let tangents1 = self.dir1.orthonormal_basis();
for i in 0..self.num_contacts as usize {
@@ -222,9 +265,9 @@ impl VelocityGroundConstraint {
mj_lambda2.angular += elt.gcross2 * elt.impulse;
for j in 0..DIM - 1 {
let elt = &self.elements[i].tangent_part[j];
mj_lambda2.linear += tangents1[j] * (-self.im2 * elt.impulse);
mj_lambda2.angular += elt.gcross2 * elt.impulse;
let elt = &self.elements[i].tangent_part;
mj_lambda2.linear += tangents1[j] * (-self.im2 * elt.impulse[j]);
mj_lambda2.angular += elt.gcross2[j] * elt.impulse[j];
}
}
@@ -236,23 +279,51 @@ impl VelocityGroundConstraint {
let mut mj_lambda2 = mj_lambdas[self.mj_lambda2 as usize];
// Solve friction.
#[cfg(feature = "dim3")]
let bitangent1 = self.dir1.cross(&self.tangent1);
#[cfg(feature = "dim2")]
let tangents1 = self.dir1.orthonormal_basis();
#[cfg(feature = "dim2")]
for i in 0..self.num_contacts as usize {
for j in 0..DIM - 1 {
let normal_elt = &self.elements[i].normal_part;
let elt = &mut self.elements[i].tangent_part[j];
let dimpulse = -tangents1[j].dot(&mj_lambda2.linear)
+ elt.gcross2.gdot(mj_lambda2.angular)
+ elt.rhs;
let limit = self.limit * normal_elt.impulse;
let new_impulse = (elt.impulse - elt.r * dimpulse).simd_clamp(-limit, limit);
let dlambda = new_impulse - elt.impulse;
elt.impulse = new_impulse;
let normal_elt = &self.elements[i].normal_part;
let elt = &mut self.elements[i].tangent_part;
let dimpulse = -tangents1[0].dot(&mj_lambda2.linear)
+ elt.gcross2[0].gdot(mj_lambda2.angular)
+ elt.rhs[0];
let limit = self.limit * normal_elt.impulse;
let new_impulse = (elt.impulse[0] - elt.r[0] * dimpulse).simd_clamp(-limit, limit);
let dlambda = new_impulse - elt.impulse[0];
elt.impulse[0] = new_impulse;
mj_lambda2.linear += tangents1[j] * (-self.im2 * dlambda);
mj_lambda2.angular += elt.gcross2 * dlambda;
}
mj_lambda2.linear += tangents1[0] * (-self.im2 * dlambda);
mj_lambda2.angular += elt.gcross2[0] * dlambda;
}
#[cfg(feature = "dim3")]
for i in 0..self.num_contacts as usize {
let limit = self.limit * self.elements[i].normal_part.impulse;
let elts = &mut self.elements[i].tangent_part;
let dimpulse_0 = -self.tangent1.dot(&mj_lambda2.linear)
+ elts.gcross2[0].gdot(mj_lambda2.angular)
+ elts.rhs[0];
let dimpulse_1 = -bitangent1.dot(&mj_lambda2.linear)
+ elts.gcross2[1].gdot(mj_lambda2.angular)
+ elts.rhs[1];
let new_impulse = na::Vector2::new(
elts.impulse[0] - elts.r[0] * dimpulse_0,
elts.impulse[1] - elts.r[1] * dimpulse_1,
);
let new_impulse = new_impulse.cap_magnitude(limit);
let dlambda = new_impulse - elts.impulse;
elts.impulse = new_impulse;
mj_lambda2.linear +=
self.tangent1 * (-self.im2 * dlambda[0]) + bitangent1 * (-self.im2 * dlambda[1]);
mj_lambda2.angular += elts.gcross2[0] * dlambda[0] + elts.gcross2[1] * dlambda[1];
}
// Solve penetration.
@@ -281,14 +352,13 @@ impl VelocityGroundConstraint {
active_contact.data.impulse = self.elements[k].normal_part.impulse;
#[cfg(feature = "dim2")]
{
active_contact.data.tangent_impulse = self.elements[k].tangent_part[0].impulse;
active_contact.data.tangent_impulse = self.elements[k].tangent_part.impulse[0];
}
#[cfg(feature = "dim3")]
{
active_contact.data.tangent_impulse = [
self.elements[k].tangent_part[0].impulse,
self.elements[k].tangent_part[1].impulse,
];
active_contact.data.tangent_impulse = self
.tangent_rot1
.inverse_transform_vector(&self.elements[k].tangent_part.impulse);
}
}
}

159
src/dynamics/solver/velocity_ground_constraint_wide.rs
View File

@@ -4,19 +4,46 @@ use crate::geometry::{ContactManifold, ContactManifoldIndex};
use crate::math::{
AngVector, AngularInertia, Point, Real, SimdReal, Vector, DIM, MAX_MANIFOLD_POINTS, SIMD_WIDTH,
};
use crate::utils::{WAngularInertia, WBasis, WCross, WDot};
#[cfg(feature = "dim2")]
use crate::utils::WBasis;
use crate::utils::{WAngularInertia, WCross, WDot};
use num::Zero;
use simba::simd::{SimdPartialOrd, SimdValue};
#[derive(Copy, Clone, Debug)]
pub(crate) struct WVelocityGroundConstraintElementPart {
pub(crate) struct WVelocityGroundConstraintTangentPart {
pub gcross2: [AngVector<SimdReal>; DIM - 1],
pub rhs: [SimdReal; DIM - 1],
#[cfg(feature = "dim2")]
pub impulse: [SimdReal; DIM - 1],
#[cfg(feature = "dim3")]
pub impulse: na::Vector2<SimdReal>,
pub r: [SimdReal; DIM - 1],
}
impl WVelocityGroundConstraintTangentPart {
pub fn zero() -> Self {
Self {
gcross2: [AngVector::zero(); DIM - 1],
rhs: [SimdReal::zero(); DIM - 1],
#[cfg(feature = "dim2")]
impulse: [SimdReal::zero(); DIM - 1],
#[cfg(feature = "dim3")]
impulse: na::zero(),
r: [SimdReal::zero(); DIM - 1],
}
}
}
#[derive(Copy, Clone, Debug)]
pub(crate) struct WVelocityGroundConstraintNormalPart {
pub gcross2: AngVector<SimdReal>,
pub rhs: SimdReal,
pub impulse: SimdReal,
pub r: SimdReal,
}
impl WVelocityGroundConstraintElementPart {
impl WVelocityGroundConstraintNormalPart {
pub fn zero() -> Self {
Self {
gcross2: AngVector::zero(),
@@ -29,15 +56,15 @@ impl WVelocityGroundConstraintElementPart {
#[derive(Copy, Clone, Debug)]
pub(crate) struct WVelocityGroundConstraintElement {
pub normal_part: WVelocityGroundConstraintElementPart,
pub tangent_parts: [WVelocityGroundConstraintElementPart; DIM - 1],
pub normal_part: WVelocityGroundConstraintNormalPart,
pub tangent_part: WVelocityGroundConstraintTangentPart,
}
impl WVelocityGroundConstraintElement {
pub fn zero() -> Self {
Self {
normal_part: WVelocityGroundConstraintElementPart::zero(),
tangent_parts: [WVelocityGroundConstraintElementPart::zero(); DIM - 1],
normal_part: WVelocityGroundConstraintNormalPart::zero(),
tangent_part: WVelocityGroundConstraintTangentPart::zero(),
}
}
}
@@ -45,6 +72,10 @@ impl WVelocityGroundConstraintElement {
#[derive(Copy, Clone, Debug)]
pub(crate) struct WVelocityGroundConstraint {
pub dir1: Vector<SimdReal>, // Non-penetration force direction for the first body.
#[cfg(feature = "dim3")]
pub tangent1: Vector<SimdReal>, // One of the friction force directions.
#[cfg(feature = "dim3")]
pub tangent_rot1: na::UnitComplex<SimdReal>, // Orientation of the tangent basis wrt. the reference basis.
pub elements: [WVelocityGroundConstraintElement; MAX_MANIFOLD_POINTS],
pub num_contacts: u8,
pub im2: SimdReal,
@@ -104,12 +135,22 @@ impl WVelocityGroundConstraint {
let warmstart_coeff = warmstart_multiplier * SimdReal::splat(params.warmstart_coeff);
let num_active_contacts = manifolds[0].data.num_active_contacts();
#[cfg(feature = "dim2")]
let tangents1 = force_dir1.orthonormal_basis();
#[cfg(feature = "dim3")]
let (tangents1, tangent_rot1) =
super::compute_tangent_contact_directions(&force_dir1, &linvel1, &linvel2);
for l in (0..num_active_contacts).step_by(MAX_MANIFOLD_POINTS) {
let manifold_points = array![|ii| &manifolds[ii].data.solver_contacts[l..]; SIMD_WIDTH];
let num_points = manifold_points[0].len().min(MAX_MANIFOLD_POINTS);
let mut constraint = WVelocityGroundConstraint {
dir1: force_dir1,
#[cfg(feature = "dim3")]
tangent1: tangents1[0],
#[cfg(feature = "dim3")]
tangent_rot1,
elements: [WVelocityGroundConstraintElement::zero(); MAX_MANIFOLD_POINTS],
im2,
limit: SimdReal::splat(0.0),
@@ -158,7 +199,7 @@ impl WVelocityGroundConstraint {
rhs +=
dist.simd_min(SimdReal::zero()) * (velocity_based_erp_inv_dt * is_resting);
constraint.elements[k].normal_part = WVelocityGroundConstraintElementPart {
constraint.elements[k].normal_part = WVelocityGroundConstraintNormalPart {
gcross2,
rhs,
impulse: impulse * warmstart_coeff,
@@ -167,29 +208,25 @@ impl WVelocityGroundConstraint {
}
// tangent parts.
let tangents1 = force_dir1.orthonormal_basis();
for j in 0..DIM - 1 {
#[cfg(feature = "dim2")]
let impulse = SimdReal::from(
#[cfg(feature = "dim2")]
let impulse = [SimdReal::from(
array![|ii| manifold_points[ii][k].data.tangent_impulse; SIMD_WIDTH],
)];
#[cfg(feature = "dim3")]
let impulse = tangent_rot1
* na::Vector2::from(
array![|ii| manifold_points[ii][k].data.tangent_impulse; SIMD_WIDTH],
);
#[cfg(feature = "dim3")]
let impulse = SimdReal::from(
array![|ii| manifold_points[ii][k].data.tangent_impulse[j]; SIMD_WIDTH],
);
constraint.elements[k].tangent_part.impulse = impulse;
for j in 0..DIM - 1 {
let gcross2 = ii2.transform_vector(dp2.gcross(-tangents1[j]));
let r = SimdReal::splat(1.0) / (im2 + gcross2.gdot(gcross2));
let rhs = (vel1 - vel2 + tangent_velocity * flipped_sign).dot(&tangents1[j]);
constraint.elements[k].tangent_parts[j] =
WVelocityGroundConstraintElementPart {
gcross2,
rhs,
impulse: impulse * warmstart_coeff,
r,
};
constraint.elements[k].tangent_part.gcross2[j] = gcross2;
constraint.elements[k].tangent_part.r[j] = r;
constraint.elements[k].tangent_part.rhs[j] = rhs;
}
}
@@ -212,6 +249,9 @@ impl WVelocityGroundConstraint {
),
};
#[cfg(feature = "dim3")]
let tangents1 = [self.tangent1, self.dir1.cross(&self.tangent1)];
#[cfg(feature = "dim2")]
let tangents1 = self.dir1.orthonormal_basis();
for i in 0..self.num_contacts as usize {
@@ -220,9 +260,9 @@ impl WVelocityGroundConstraint {
mj_lambda2.angular += elt.gcross2 * elt.impulse;
for j in 0..DIM - 1 {
let elt = &self.elements[i].tangent_parts[j];
mj_lambda2.linear += tangents1[j] * (-self.im2 * elt.impulse);
mj_lambda2.angular += elt.gcross2 * elt.impulse;
let elt = &self.elements[i].tangent_part;
mj_lambda2.linear += tangents1[j] * (-self.im2 * elt.impulse[j]);
mj_lambda2.angular += elt.gcross2[j] * elt.impulse[j];
}
}
@@ -242,25 +282,52 @@ impl WVelocityGroundConstraint {
),
};
// Solve friction first.
// Solve friction.
#[cfg(feature = "dim3")]
let bitangent1 = self.dir1.cross(&self.tangent1);
#[cfg(feature = "dim2")]
let tangents1 = self.dir1.orthonormal_basis();
#[cfg(feature = "dim2")]
for i in 0..self.num_contacts as usize {
let normal_elt = &self.elements[i].normal_part;
for j in 0..DIM - 1 {
let elt = &mut self.elements[i].tangent_parts[j];
let dimpulse = -tangents1[j].dot(&mj_lambda2.linear)
+ elt.gcross2.gdot(mj_lambda2.angular)
+ elt.rhs;
let limit = self.limit * normal_elt.impulse;
let new_impulse = (elt.impulse - elt.r * dimpulse).simd_clamp(-limit, limit);
let dlambda = new_impulse - elt.impulse;
elt.impulse = new_impulse;
let elt = &mut self.elements[i].tangent_part;
let dimpulse = -tangents1[0].dot(&mj_lambda2.linear)
+ elt.gcross2[0].gdot(mj_lambda2.angular)
+ elt.rhs[0];
let limit = self.limit * normal_elt.impulse;
let new_impulse = (elt.impulse[0] - elt.r[0] * dimpulse).simd_clamp(-limit, limit);
let dlambda = new_impulse - elt.impulse[0];
elt.impulse[0] = new_impulse;
mj_lambda2.linear += tangents1[j] * (-self.im2 * dlambda);
mj_lambda2.angular += elt.gcross2 * dlambda;
}
mj_lambda2.linear += tangents1[0] * (-self.im2 * dlambda);
mj_lambda2.angular += elt.gcross2[0] * dlambda;
}
#[cfg(feature = "dim3")]
for i in 0..self.num_contacts as usize {
let limit = self.limit * self.elements[i].normal_part.impulse;
let elts = &mut self.elements[i].tangent_part;
let dimpulse_0 = -self.tangent1.dot(&mj_lambda2.linear)
+ elts.gcross2[0].gdot(mj_lambda2.angular)
+ elts.rhs[0];
let dimpulse_1 = -bitangent1.dot(&mj_lambda2.linear)
+ elts.gcross2[1].gdot(mj_lambda2.angular)
+ elts.rhs[1];
let new_impulse = na::Vector2::new(
elts.impulse[0] - elts.r[0] * dimpulse_0,
elts.impulse[1] - elts.r[1] * dimpulse_1,
);
let new_impulse = new_impulse.simd_cap_magnitude(limit);
let dlambda = new_impulse - elts.impulse;
elts.impulse = new_impulse;
mj_lambda2.linear +=
self.tangent1 * (-self.im2 * dlambda[0]) + bitangent1 * (-self.im2 * dlambda[1]);
mj_lambda2.angular += elts.gcross2[0] * dlambda[0] + elts.gcross2[1] * dlambda[1];
}
// Solve non-penetration after friction.
@@ -286,11 +353,12 @@ impl WVelocityGroundConstraint {
pub fn writeback_impulses(&self, manifolds_all: &mut [&mut ContactManifold]) {
for k in 0..self.num_contacts as usize {
let impulses: [_; SIMD_WIDTH] = self.elements[k].normal_part.impulse.into();
let tangent_impulses: [_; SIMD_WIDTH] =
self.elements[k].tangent_parts[0].impulse.into();
#[cfg(feature = "dim2")]
let tangent_impulses: [_; SIMD_WIDTH] = self.elements[k].tangent_part.impulse[0].into();
#[cfg(feature = "dim3")]
let bitangent_impulses: [_; SIMD_WIDTH] =
self.elements[k].tangent_parts[1].impulse.into();
let tangent_impulses = self
.tangent_rot1
.inverse_transform_vector(&self.elements[k].tangent_part.impulse);
for ii in 0..SIMD_WIDTH {
let manifold = &mut manifolds_all[self.manifold_id[ii]];
@@ -304,8 +372,7 @@ impl WVelocityGroundConstraint {
}
#[cfg(feature = "dim3")]
{
active_contact.data.tangent_impulse =
[tangent_impulses[ii], bitangent_impulses[ii]];
active_contact.data.tangent_impulse = tangent_impulses.extract(ii);
}
}
}

16
src/geometry/contact_pair.rs
View File

@@ -37,26 +37,14 @@ pub struct ContactData {
/// The friction impulses along the basis orthonormal to the contact normal, applied to the first
/// collider's rigid-body.
#[cfg(feature = "dim3")]
pub tangent_impulse: [Real; 2],
}
impl ContactData {
#[cfg(feature = "dim2")]
pub(crate) fn zero_tangent_impulse() -> Real {
0.0
}
#[cfg(feature = "dim3")]
pub(crate) fn zero_tangent_impulse() -> [Real; 2] {
[0.0, 0.0]
}
pub tangent_impulse: na::Vector2<Real>,
}
impl Default for ContactData {
fn default() -> Self {
Self {
impulse: 0.0,
tangent_impulse: Self::zero_tangent_impulse(),
tangent_impulse: na::zero(),
}
}
}

10
src/pipeline/physics_hooks.rs
View File

@@ -81,7 +81,15 @@ impl<'a> ContactModificationContext<'a> {
// normal, so remove all the contacts and mark further contacts
// as forbidden.
self.solver_contacts.clear();
*self.user_data = CONTACT_CURRENTLY_FORBIDDEN;
// NOTE: in some very rare cases `local_n1` will be
// zero if the objects are exactly touching at one point.
// So in this case we can't really conclude.
// If the norm is non-zero, then we can tell we need to forbid
// further contacts. Otherwise we have to wait for the next frame.
if self.manifold.local_n1.norm_squared() > 0.1 {
*self.user_data = CONTACT_CURRENTLY_FORBIDDEN;
}
}
}
CONTACT_CURRENTLY_FORBIDDEN => {

12
src/utils.rs
View File

@@ -107,6 +107,8 @@ pub trait WBasis: Sized {
type Basis;
/// Computes the vectors which, when combined with `self`, form an orthonormal basis.
fn orthonormal_basis(self) -> Self::Basis;
/// Computes a vector orthogonal to `self` with a unit length (if `self` has a unit length).
fn orthonormal_vector(self) -> Self;
}
impl<N: SimdRealField> WBasis for Vector2<N> {
@@ -114,6 +116,9 @@ impl<N: SimdRealField> WBasis for Vector2<N> {
fn orthonormal_basis(self) -> [Vector2<N>; 1] {
[Vector2::new(-self.y, self.x)]
}
fn orthonormal_vector(self) -> Vector2<N> {
Vector2::new(-self.y, self.x)
}
}
impl<N: SimdRealField + WSign<N>> WBasis for Vector3<N> {
@@ -134,6 +139,13 @@ impl<N: SimdRealField + WSign<N>> WBasis for Vector3<N> {
Vector3::new(b, sign + self.y * self.y * a, -self.y),
]
}
fn orthonormal_vector(self) -> Vector3<N> {
let sign = self.z.copy_sign_to(N::one());
let a = -N::one() / (sign + self.z);
let b = self.x * self.y * a;
Vector3::new(b, sign + self.y * self.y * a, -self.y)
}
}
pub(crate) trait WVec: Sized {

4
src_testbed/physx_backend.rs
View File

@@ -186,6 +186,10 @@ impl PhysxWorld {
let pos = rb.position().into_physx();
if rb.is_dynamic() {
let mut actor = physics.create_dynamic(&pos, rapier_handle).unwrap();
let linvel = rb.linvel().into_physx();
let angvel = rb.angvel().into_physx();
actor.set_linear_velocity(&linvel, true);
actor.set_angular_velocity(&angvel, true);
actor.set_solver_iteration_counts(
integration_parameters.max_position_iterations as u32,
integration_parameters.max_velocity_iterations as u32,