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authorSébastien Crozet <sebcrozet@dimforge.com>2024-01-21 21:02:23 +0100
committerSébastien Crozet <sebcrozet@dimforge.com>2024-01-21 21:02:27 +0100
commit9b87f06a856c4d673642e210f8b0986cfdbac3af (patch)
treeb4f4eaac0e5004f8ba3fccd42e5aea4fd565dcc6 /src/dynamics/solver/generic_velocity_ground_constraint.rs
parent9ac3503b879f95fcdf5414470ba5aedf195b9a97 (diff)
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feat: implement new "small-steps" solver + joint improvements
Diffstat (limited to 'src/dynamics/solver/generic_velocity_ground_constraint.rs')
-rw-r--r--src/dynamics/solver/generic_velocity_ground_constraint.rs240
1 files changed, 0 insertions, 240 deletions
diff --git a/src/dynamics/solver/generic_velocity_ground_constraint.rs b/src/dynamics/solver/generic_velocity_ground_constraint.rs
deleted file mode 100644
index 91bb9fb..0000000
--- a/src/dynamics/solver/generic_velocity_ground_constraint.rs
+++ /dev/null
@@ -1,240 +0,0 @@
-use crate::dynamics::solver::VelocityGroundConstraint;
-use crate::dynamics::{IntegrationParameters, MultibodyJointSet, RigidBodySet, RigidBodyVelocity};
-use crate::geometry::{ContactManifold, ContactManifoldIndex};
-use crate::math::{Point, Real, DIM, MAX_MANIFOLD_POINTS};
-use crate::utils::WCross;
-
-use super::{
- AnyVelocityConstraint, VelocityGroundConstraintElement, VelocityGroundConstraintNormalPart,
-};
-#[cfg(feature = "dim2")]
-use crate::utils::WBasis;
-use na::DVector;
-
-#[derive(Copy, Clone, Debug)]
-pub(crate) struct GenericVelocityGroundConstraint {
- // 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: VelocityGroundConstraint,
- pub j_id: usize,
- pub ndofs2: usize,
-}
-
-impl GenericVelocityGroundConstraint {
- pub fn generate(
- params: &IntegrationParameters,
- manifold_id: ContactManifoldIndex,
- manifold: &ContactManifold,
- bodies: &RigidBodySet,
- multibodies: &MultibodyJointSet,
- out_constraints: &mut Vec<AnyVelocityConstraint>,
- jacobians: &mut DVector<Real>,
- jacobian_id: &mut usize,
- insert_at: Option<usize>,
- ) {
- let cfm_factor = params.cfm_factor();
- let inv_dt = params.inv_dt();
- let erp_inv_dt = params.erp_inv_dt();
-
- let mut handle1 = manifold.data.rigid_body1;
- let mut handle2 = manifold.data.rigid_body2;
- let flipped = manifold.data.relative_dominance < 0;
-
- let (force_dir1, flipped_multiplier) = if flipped {
- std::mem::swap(&mut handle1, &mut handle2);
- (manifold.data.normal, -1.0)
- } else {
- (-manifold.data.normal, 1.0)
- };
-
- let (vels1, world_com1) = if let Some(handle1) = handle1 {
- let rb1 = &bodies[handle1];
- (rb1.vels, rb1.mprops.world_com)
- } else {
- (RigidBodyVelocity::zero(), Point::origin())
- };
-
- let rb2 = &bodies[handle2.unwrap()];
- let (vels2, mprops2) = (&rb2.vels, &rb2.mprops);
-
- let (mb2, link_id2) = handle2
- .and_then(|h| multibodies.rigid_body_link(h))
- .map(|m| (&multibodies[m.multibody], m.id))
- .unwrap();
- let mj_lambda2 = mb2.solver_id;
-
- #[cfg(feature = "dim2")]
- let tangents1 = force_dir1.orthonormal_basis();
- #[cfg(feature = "dim3")]
- let tangents1 =
- super::compute_tangent_contact_directions(&force_dir1, &vels1.linvel, &vels2.linvel);
-
- let multibodies_ndof = mb2.ndofs();
- // 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 && !cfg!(feature = "parallel") {
- 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 is_fast_contact = false;
- let mut constraint = VelocityGroundConstraint {
- dir1: force_dir1,
- #[cfg(feature = "dim3")]
- tangent1: tangents1[0],
- elements: [VelocityGroundConstraintElement::zero(); MAX_MANIFOLD_POINTS],
- im2: mprops2.effective_inv_mass,
- cfm_factor,
- limit: 0.0,
- 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 - world_com1;
- let dp2 = manifold_point.point - mprops2.world_com;
-
- let vel1 = vels1.linvel + vels1.angvel.gcross(dp1);
- let vel2 = vels2.linvel + vels2.angvel.gcross(dp2);
-
- constraint.limit = manifold_point.friction;
- constraint.manifold_contact_id[k] = manifold_point.contact_id;
-
- // Normal part.
- {
- let torque_dir2 = dp2.gcross(-force_dir1);
- let inv_r2 = mb2
- .fill_jacobians(
- link_id2,
- -force_dir1,
- #[cfg(feature = "dim2")]
- na::vector!(torque_dir2),
- #[cfg(feature = "dim3")]
- torque_dir2,
- jacobian_id,
- jacobians,
- )
- .0;
-
- let r = crate::utils::inv(inv_r2);
-
- let is_bouncy = manifold_point.is_bouncy() as u32 as Real;
- let is_resting = 1.0 - is_bouncy;
-
- let dvel = (vel1 - vel2).dot(&force_dir1);
- let mut rhs_wo_bias = (1.0 + is_bouncy * manifold_point.restitution) * dvel;
- rhs_wo_bias += manifold_point.dist.max(0.0) * inv_dt;
- rhs_wo_bias *= is_bouncy + is_resting;
- let rhs_bias =
- /* is_resting * */ erp_inv_dt * manifold_point.dist.clamp(-params.max_penetration_correction, 0.0);
-
- let rhs = rhs_wo_bias + rhs_bias;
- is_fast_contact =
- is_fast_contact || (-rhs * params.dt > rb2.ccd.ccd_thickness * 0.5);
-
- constraint.elements[k].normal_part = VelocityGroundConstraintNormalPart {
- gcross2: na::zero(), // Unused for generic constraints.
- rhs,
- 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_dir2 = dp2.gcross(-tangents1[j]);
- let inv_r2 = mb2
- .fill_jacobians(
- link_id2,
- -tangents1[j],
- #[cfg(feature = "dim2")]
- na::vector![torque_dir2],
- #[cfg(feature = "dim3")]
- torque_dir2,
- jacobian_id,
- jacobians,
- )
- .0;
-
- let r = crate::utils::inv(inv_r2);
-
- let rhs = (vel1 - vel2
- + flipped_multiplier * 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;
- }
- }
- }
-
- constraint.cfm_factor = if is_fast_contact { 1.0 } else { cfm_factor };
-
- let constraint = GenericVelocityGroundConstraint {
- velocity_constraint: constraint,
- j_id: chunk_j_id,
- ndofs2: mb2.ndofs(),
- };
-
- if let Some(at) = insert_at {
- out_constraints[at + _l] =
- AnyVelocityConstraint::NongroupedGenericGround(constraint);
- } else {
- out_constraints.push(AnyVelocityConstraint::NongroupedGenericGround(constraint));
- }
- }
- }
-
- pub fn solve(
- &mut self,
- jacobians: &DVector<Real>,
- generic_mj_lambdas: &mut DVector<Real>,
- solve_restitution: bool,
- solve_friction: bool,
- ) {
- let mj_lambda2 = self.velocity_constraint.mj_lambda2 as usize;
-
- let elements = &mut self.velocity_constraint.elements
- [..self.velocity_constraint.num_contacts as usize];
- VelocityGroundConstraintElement::generic_solve_group(
- self.velocity_constraint.cfm_factor,
- elements,
- jacobians,
- self.velocity_constraint.limit,
- self.ndofs2,
- self.j_id,
- mj_lambda2,
- generic_mj_lambdas,
- solve_restitution,
- solve_friction,
- );
- }
-
- pub fn writeback_impulses(&self, manifolds_all: &mut [&mut ContactManifold]) {
- self.velocity_constraint.writeback_impulses(manifolds_all);
- }
-
- pub fn remove_cfm_and_bias_from_rhs(&mut self) {
- self.velocity_constraint.remove_cfm_and_bias_from_rhs();
- }
-}