Add a max penetration correction integration parameter

CHANGELOG.md

@@ -1,3 +1,12 @@
+- `RigidBody::set_linvel` and `RigidBody::set_angvel` no longer modify the velocity of static bodies.
+- `RigidBody::set_body_type` will reset the velocity of a rigid-body to zero if it is static.
+- `RigidBodyMassPropsFlags` has been renamed to `LockedAxes`.
+- Don’t automatically clear forces at the end of a timestep.
+- Don’t reset the velocity of kinematic bodies to zero at the end of the timestep.
+- `RigidsBody::apply_force`, `::apply_torque`, `::apply_force_at_point` have been renamed to `::add_force`,
+  `::add_torque`, and `::add_force_at_point` to better reflect the fact that they are not cleared at the end
+  of the timestep.
+
 ## v0.12.0-alpha.0 (2 Jan. 2022)
 ### Fixed
 - Fixed `RigidBody::restrict_rotations` to properly take into account the axes to lock.

src/dynamics/integration_parameters.rs

@@ -36,6 +36,8 @@ pub struct IntegrationParameters {
 
     /// Amount of penetration the engine wont attempt to correct (default: `0.001m`).
     pub allowed_linear_error: Real,
+    /// Maximum amount of penetration the solver will attempt to resolve in one timestep.
+    pub max_penetration_correction: Real,
     /// The maximal distance separating two objects that will generate predictive contacts (default: `0.002`).
     pub prediction_distance: Real,
     /// Maximum number of iterations performed to solve non-penetration and joint constraints (default: `4`).
@@ -150,6 +152,7 @@ impl Default for IntegrationParameters {
             joint_erp: 1.0,
             joint_damping_ratio: 1.0,
             allowed_linear_error: 0.001, // 0.005
+            max_penetration_correction: Real::MAX,
             prediction_distance: 0.002,
             max_velocity_iterations: 4,
             max_velocity_friction_iterations: 8,

src/dynamics/solver/generic_velocity_constraint.rs

@@ -212,7 +212,7 @@ impl GenericVelocityConstraint {
                     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.min(0.0);
+                        /* is_resting * */ erp_inv_dt * manifold_point.dist.clamp(-params.max_penetration_correction, 0.0);
 
                     constraint.elements[k].normal_part = VelocityConstraintNormalPart {
                         gcross1,

src/dynamics/solver/generic_velocity_ground_constraint.rs

@@ -148,7 +148,7 @@ impl GenericVelocityGroundConstraint {
                     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.min(0.0);
+                        /* is_resting * */ erp_inv_dt * manifold_point.dist.clamp(-params.max_penetration_correction, 0.0);
 
                     constraint.elements[k].normal_part = VelocityGroundConstraintNormalPart {
                         gcross2: na::zero(), // Unused for generic constraints.

src/dynamics/solver/velocity_constraint.rs

@@ -283,7 +283,7 @@ impl VelocityConstraint {
                     rhs_wo_bias *= is_bouncy + is_resting;
                     let rhs_bias = /* is_resting
                         * */  erp_inv_dt
-                        * (manifold_point.dist + params.allowed_linear_error).min(0.0);
+                        * (manifold_point.dist + params.allowed_linear_error).clamp(-params.max_penetration_correction, 0.0);
                     constraint.elements[k].normal_part = VelocityConstraintNormalPart {
                         gcross1,
                         gcross2,

src/dynamics/solver/velocity_constraint_wide.rs

@@ -49,6 +49,7 @@ impl WVelocityConstraint {
         let inv_dt = SimdReal::splat(params.inv_dt());
         let allowed_lin_err = SimdReal::splat(params.allowed_linear_error);
         let erp_inv_dt = SimdReal::splat(params.erp_inv_dt());
+        let max_penetration_correction = SimdReal::splat(params.max_penetration_correction);
 
         let handles1 = gather![|ii| manifolds[ii].data.rigid_body1.unwrap()];
         let handles2 = gather![|ii| manifolds[ii].data.rigid_body2.unwrap()];
@@ -145,7 +146,8 @@ impl WVelocityConstraint {
                         (SimdReal::splat(1.0) + is_bouncy * restitution) * projected_velocity;
                     rhs_wo_bias += dist.simd_max(SimdReal::zero()) * inv_dt;
                     rhs_wo_bias *= is_bouncy + is_resting;
-                    let rhs_bias = (dist + allowed_lin_err).simd_min(SimdReal::zero())
+                    let rhs_bias = (dist + allowed_lin_err)
+                        .simd_clamp(-max_penetration_correction, SimdReal::zero())
                         * (erp_inv_dt/* * is_resting */);
 
                     constraint.elements[k].normal_part = VelocityConstraintNormalPart {

src/dynamics/solver/velocity_ground_constraint.rs

@@ -167,7 +167,7 @@ impl VelocityGroundConstraint {
                     rhs_wo_bias *= is_bouncy + is_resting;
                     let rhs_bias = /* is_resting
                         * */ erp_inv_dt
-                        * (manifold_point.dist + params.allowed_linear_error).min(0.0);
+                        * (manifold_point.dist + params.allowed_linear_error).clamp(-params.max_penetration_correction, 0.0);
 
                     constraint.elements[k].normal_part = VelocityGroundConstraintNormalPart {
                         gcross2,

src/dynamics/solver/velocity_ground_constraint_wide.rs

@@ -44,6 +44,7 @@ impl WVelocityGroundConstraint {
         let inv_dt = SimdReal::splat(params.inv_dt());
         let allowed_lin_err = SimdReal::splat(params.allowed_linear_error);
         let erp_inv_dt = SimdReal::splat(params.erp_inv_dt());
+        let max_penetration_correction = SimdReal::splat(params.max_penetration_correction);
 
         let mut handles1 = gather![|ii| manifolds[ii].data.rigid_body1];
         let mut handles2 = gather![|ii| manifolds[ii].data.rigid_body2];
@@ -150,7 +151,8 @@ impl WVelocityGroundConstraint {
                         (SimdReal::splat(1.0) + is_bouncy * restitution) * projected_velocity;
                     rhs_wo_bias += dist.simd_max(SimdReal::zero()) * inv_dt;
                     rhs_wo_bias *= is_bouncy + is_resting;
-                    let rhs_bias = (dist + allowed_lin_err).simd_min(SimdReal::zero())
+                    let rhs_bias = (dist + allowed_lin_err)
+                        .simd_clamp(-max_penetration_correction, SimdReal::zero())
                         * (erp_inv_dt/* * is_resting */);
 
                     constraint.elements[k].normal_part = VelocityGroundConstraintNormalPart {