Complete the implementation of non-simd joint motor for the revolute joint.

14 files changed, 485 insertions, 345 deletions

diff --git a/src/dynamics/joint/generic_joint.rs b/src/dynamics/joint/generic_joint.rs
index fa35520..5d776b0 100644
--- a/src/dynamics/joint/generic_joint.rs
+++ b/src/dynamics/joint/generic_joint.rs
@@ -54,6 +54,13 @@ impl GenericJoint {
         }
     }
 
+    pub fn set_dof_vel(&mut self, dof: u8, target_vel: Real, max_force: Real) {
+        self.min_velocity[dof as usize] = target_vel;
+        self.max_velocity[dof as usize] = target_vel;
+        self.min_impulse[dof as usize] = -max_force;
+        self.max_impulse[dof as usize] = max_force;
+    }
+
     pub fn free_dof(&mut self, dof: u8) {
         self.min_position[dof as usize] = -Real::MAX;
         self.max_position[dof as usize] = Real::MAX;
@@ -82,6 +89,18 @@ impl From<RevoluteJoint> for GenericJoint {
 
         let mut result = Self::new(local_anchor1, local_anchor2);
         result.free_dof(3);
+
+        if joint.motor_damping != 0.0 {
+            result.set_dof_vel(3, joint.motor_target_vel, joint.motor_max_impulse);
+        }
+
+        result.impulse[0] = joint.impulse[0];
+        result.impulse[1] = joint.impulse[1];
+        result.impulse[2] = joint.impulse[2];
+        result.impulse[3] = joint.motor_impulse;
+        result.impulse[4] = joint.impulse[3];
+        result.impulse[5] = joint.impulse[4];
+
         result
     }
 }
@@ -92,6 +111,9 @@ impl From<BallJoint> for GenericJoint {
         let local_anchor2 = Isometry::new(joint.local_anchor2.coords, na::zero());
 
         let mut result = Self::new(local_anchor1, local_anchor2);
+        result.impulse[0] = joint.impulse[0];
+        result.impulse[1] = joint.impulse[1];
+        result.impulse[2] = joint.impulse[2];
         result.free_dof(3);
         result.free_dof(4);
         result.free_dof(5);
diff --git a/src/dynamics/joint/joint.rs b/src/dynamics/joint/joint.rs
index 31c5e0a..fe77b4b 100644
--- a/src/dynamics/joint/joint.rs
+++ b/src/dynamics/joint/joint.rs
@@ -1,8 +1,6 @@
 #[cfg(feature = "dim3")]
 use crate::dynamics::RevoluteJoint;
-use crate::dynamics::{
-    BallJoint, FixedJoint, GenericJoint, JointHandle, PrismaticJoint, RigidBodyHandle,
-};
+use crate::dynamics::{BallJoint, FixedJoint, JointHandle, PrismaticJoint, RigidBodyHandle};
 
 #[derive(Copy, Clone)]
 #[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
@@ -19,7 +17,7 @@ pub enum JointParams {
     /// A revolute joint that removes all degrees of degrees of freedom between the affected
     /// bodies except for the translation along one axis.
     RevoluteJoint(RevoluteJoint),
-    GenericJoint(GenericJoint),
+    // GenericJoint(GenericJoint),
 }
 
 impl JointParams {
@@ -29,7 +27,7 @@ impl JointParams {
             JointParams::BallJoint(_) => 0,
             JointParams::FixedJoint(_) => 1,
             JointParams::PrismaticJoint(_) => 2,
-            JointParams::GenericJoint(_) => 3,
+            // JointParams::GenericJoint(_) => 3,
             #[cfg(feature = "dim3")]
             JointParams::RevoluteJoint(_) => 4,
         }
@@ -53,14 +51,14 @@ impl JointParams {
         }
     }
 
-    /// Gets a reference to the underlying generic joint, if `self` is one.
-    pub fn as_generic_joint(&self) -> Option<&GenericJoint> {
-        if let JointParams::GenericJoint(j) = self {
-            Some(j)
-        } else {
-            None
-        }
-    }
+    // /// Gets a reference to the underlying generic joint, if `self` is one.
+    // pub fn as_generic_joint(&self) -> Option<&GenericJoint> {
+    //     if let JointParams::GenericJoint(j) = self {
+    //         Some(j)
+    //     } else {
+    //         None
+    //     }
+    // }
 
     /// Gets a reference to the underlying prismatic joint, if `self` is one.
     pub fn as_prismatic_joint(&self) -> Option<&PrismaticJoint> {
@@ -94,11 +92,11 @@ impl From<FixedJoint> for JointParams {
     }
 }
 
-impl From<GenericJoint> for JointParams {
-    fn from(j: GenericJoint) -> Self {
-        JointParams::GenericJoint(j)
-    }
-}
+// impl From<GenericJoint> for JointParams {
+//     fn from(j: GenericJoint) -> Self {
+//         JointParams::GenericJoint(j)
+//     }
+// }
 
 #[cfg(feature = "dim3")]
 impl From<RevoluteJoint> for JointParams {
diff --git a/src/dynamics/joint/mod.rs b/src/dynamics/joint/mod.rs
index 92dd715..72a7483 100644
--- a/src/dynamics/joint/mod.rs
+++ b/src/dynamics/joint/mod.rs
@@ -1,18 +1,20 @@
 pub use self::ball_joint::BallJoint;
 pub use self::fixed_joint::FixedJoint;
-pub use self::generic_joint::GenericJoint;
+// pub use self::generic_joint::GenericJoint;
 pub use self::joint::{Joint, JointParams};
 pub(crate) use self::joint_set::{JointGraphEdge, JointIndex};
 pub use self::joint_set::{JointHandle, JointSet};
 pub use self::prismatic_joint::PrismaticJoint;
 #[cfg(feature = "dim3")]
 pub use self::revolute_joint::RevoluteJoint;
+pub use self::spring_model::SpringModel;
 
 mod ball_joint;
 mod fixed_joint;
-mod generic_joint;
+// mod generic_joint;
 mod joint;
 mod joint_set;
 mod prismatic_joint;
 #[cfg(feature = "dim3")]
 mod revolute_joint;
+mod spring_model;
diff --git a/src/dynamics/joint/revolute_joint.rs b/src/dynamics/joint/revolute_joint.rs
index ad7db0d..9af0ae6 100644
--- a/src/dynamics/joint/revolute_joint.rs
+++ b/src/dynamics/joint/revolute_joint.rs
@@ -1,6 +1,7 @@
-use crate::math::{Point, Real, Vector};
+use crate::dynamics::SpringModel;
+use crate::math::{Isometry, Point, Real, Vector};
 use crate::utils::WBasis;
-use na::{Unit, Vector5};
+use na::{RealField, Unit, Vector5};
 
 #[derive(Copy, Clone)]
 #[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
@@ -22,6 +23,28 @@ pub struct RevoluteJoint {
     ///
     /// The impulse applied to the second body is given by `-impulse`.
     pub impulse: Vector5<Real>,
+    /// The target relative angular velocity the motor will attempt to reach.
+    pub motor_target_vel: Real,
+    /// The target relative angle along the joint axis the motor will attempt to reach.
+    pub motor_target_pos: Real,
+    /// The motor's stiffness.
+    /// See the documentation of `SpringModel` for more information on this parameter.
+    pub motor_stiffness: Real,
+    /// The motor's damping.
+    /// See the documentation of `SpringModel` for more information on this parameter.
+    pub motor_damping: Real,
+    /// The maximal impulse the motor is able to deliver.
+    pub motor_max_impulse: Real,
+    /// The angular impulse applied by the motor.
+    pub motor_impulse: Real,
+    /// The spring-like model used by the motor to reach the target velocity and .
+    pub motor_model: SpringModel,
+    // Used to handle cases where the position target ends up being more than pi radians away.
+    pub(crate) motor_last_angle: Real,
+    // The angular impulse expressed in world-space.
+    pub(crate) world_ang_impulse: Vector<Real>,
+    // The world-space orientation of the free axis of the first attached body.
+    pub(crate) prev_axis1: Vector<Real>,
 }
 
 impl RevoluteJoint {
@@ -41,6 +64,74 @@ impl RevoluteJoint {
             basis1: local_axis1.orthonormal_basis(),
             basis2: local_axis2.orthonormal_basis(),
             impulse: na::zero(),
+            world_ang_impulse: na::zero(),
+            motor_target_vel: 0.0,
+            motor_target_pos: 0.0,
+            motor_stiffness: 0.0,
+            motor_damping: 0.0,
+            motor_max_impulse: Real::MAX,
+            motor_impulse: 0.0,
+            prev_axis1: *local_axis1,
+            motor_model: SpringModel::VelocityBased,
+            motor_last_angle: 0.0,
         }
     }
+
+    pub fn configure_motor_model(&mut self, model: SpringModel) {
+        self.motor_model = model;
+    }
+
+    pub fn configure_motor_velocity(&mut self, target_vel: Real, factor: Real) {
+        self.configure_motor(self.motor_target_pos, target_vel, 0.0, factor)
+    }
+
+    pub fn configure_motor_position(&mut self, target_pos: Real, stiffness: Real, damping: Real) {
+        self.configure_motor(target_pos, 0.0, stiffness, damping)
+    }
+
+    pub fn configure_motor(
+        &mut self,
+        target_pos: Real,
+        target_vel: Real,
+        stiffness: Real,
+        damping: Real,
+    ) {
+        self.motor_target_vel = target_vel;
+        self.motor_target_pos = target_pos;
+        self.motor_stiffness = stiffness;
+        self.motor_damping = damping;
+    }
+
+    /// Estimates the current position of the motor angle.
+    pub fn estimate_motor_angle(
+        &self,
+        body_pos1: &Isometry<Real>,
+        body_pos2: &Isometry<Real>,
+    ) -> Real {
+        let motor_axis1 = body_pos1 * self.local_axis1;
+        let ref1 = body_pos1 * self.basis1[0];
+        let ref2 = body_pos2 * self.basis2[0];
+
+        let last_angle_cycles = (self.motor_last_angle / Real::two_pi()).trunc() * Real::two_pi();
+
+        // Measure the position between 0 and 2-pi
+        let new_angle = if ref1.cross(&ref2).dot(&motor_axis1) < 0.0 {
+            Real::two_pi() - ref1.angle(&ref2)
+        } else {
+            ref1.angle(&ref2)
+        };
+
+        // The last angle between 0 and 2-pi
+        let last_angle_zero_two_pi = self.motor_last_angle - last_angle_cycles;
+
+        // Figure out the smallest angle differance.
+        let mut angle_diff = new_angle - last_angle_zero_two_pi;
+        if angle_diff > Real::pi() {
+            angle_diff -= Real::two_pi()
+        } else if angle_diff < -Real::pi() {
+            angle_diff += Real::two_pi()
+        }
+
+        self.motor_last_angle + angle_diff
+    }
 }
diff --git a/src/dynamics/joint/spring_model.rs b/src/dynamics/joint/spring_model.rs
new file mode 100644
index 0000000..dd6035d
--- /dev/null
+++ b/src/dynamics/joint/spring_model.rs
@@ -0,0 +1,59 @@
+use crate::math::Real;
+
+/// The spring-like model used for constraints resolution.
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+#[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
+pub enum SpringModel {
+    /// No equation is solved.
+    Disabled,
+    /// The solved spring-like equation is:
+    /// `delta_velocity(t + dt) = stiffness / dt * (target_pos - pos(t)) + damping * (target_vel - vel(t))`
+    ///
+    /// Here the `stiffness` is the ratio of position error to be solved at each timestep (like
+    /// a velocity-based ERP), and the `damping` is the ratio of velocity error to be solved at
+    /// each timestep.
+    VelocityBased,
+    /// The solved spring-like equation is:
+    /// `acceleration(t + dt) = stiffness * (target_pos - pos(t)) + damping * (target_vel - vel(t))`
+    AccelerationBased,
+    /// The solved spring-like equation is:
+    /// `force(t + dt) = stiffness * (target_pos - pos(t + dt)) + damping * (target_vel - vel(t + dt))`
+    ForceBased,
+}
+
+impl SpringModel {
+    /// Combines the coefficients used for solving the spring equation.
+    ///
+    /// Returns the new coefficients (stiffness, damping, inv_lhs_scale, keep_inv_lhs)
+    /// coefficients for the equivalent impulse-based equation. These new
+    /// coefficients must be used in the following way:
+    /// - `rhs = (stiffness * pos_err + damping * vel_err) / gamma`.
+    /// - `new_inv_lhs = gamma * if keep_inv_lhs { inv_lhs } else { 1.0 }`.
+    /// Note that the returned `gamma` will be zero if both `stiffness` and `damping` are zero.
+    pub fn combine_coefficients(
+        self,
+        dt: Real,
+        stiffness: Real,
+        damping: Real,
+    ) -> (Real, Real, Real, bool) {
+        match self {
+            SpringModel::VelocityBased => (stiffness * crate::utils::inv(dt), damping, 1.0, true),
+            SpringModel::AccelerationBased => {
+                let effective_stiffness = stiffness * dt;
+                let effective_damping = damping * dt;
+                // TODO: Using gamma behaves very badly for some reasons.
+                // Maybe I got the formulation wrong, so let's keep it to 1.0 for now,
+                // and get back to this later.
+                // let gamma = effective_stiffness * dt + effective_damping;
+                (effective_stiffness, effective_damping, 1.0, true)
+            }
+            SpringModel::ForceBased => {
+                let effective_stiffness = stiffness * dt;
+                let effective_damping = damping * dt;
+                let gamma = effective_stiffness * dt + effective_damping;
+                (effective_stiffness, effective_damping, gamma, false)
+            }
+            SpringModel::Disabled => return (0.0, 0.0, 0.0, false),
+        }
+    }
+}
diff --git a/src/dynamics/mod.rs b/src/dynamics/mod.rs
index 3b6a977..eab6916 100644
--- a/src/dynamics/mod.rs
+++ b/src/dynamics/mod.rs
@@ -5,7 +5,14 @@ pub(crate) use self::joint::JointIndex;
 #[cfg(feature = "dim3")]
 pub use self::joint::RevoluteJoint;
 pub use self::joint::{
-    BallJoint, FixedJoint, GenericJoint, Joint, JointHandle, JointParams, JointSet, PrismaticJoint,
+    BallJoint,
+    FixedJoint,
+    Joint,
+    JointHandle,
+    JointParams,
+    JointSet,
+    PrismaticJoint,
+    SpringModel, // GenericJoint
 };
 pub use self::rigid_body::{ActivationStatus, BodyStatus, RigidBody, RigidBodyBuilder};
 pub use self::rigid_body_set::{BodyPair, RigidBodyHandle, RigidBodySet};
diff --git a/src/dynamics/solver/joint_constraint/generic_velocity_constraint.rs b/src/dynamics/solver/joint_constraint/generic_velocity_constraint.rs
index 0208dda..f391873 100644
--- a/src/dynamics/solver/joint_constraint/generic_velocity_constraint.rs
+++ b/src/dynamics/solver/joint_constraint/generic_velocity_constraint.rs
@@ -32,7 +32,8 @@ pub(crate) struct GenericVelocityConstraint {
 
     r1: Vector<Real>,
     r2: Vector<Real>,
-    basis: Rotation<Real>,
+    basis1: Rotation<Real>,
+    basis2: Rotation<Real>,
     dependant_set_mask: SpacialVector<Real>,
 
     vel: GenericConstraintPart,
@@ -44,22 +45,22 @@ impl GenericVelocityConstraint {
         max_velocity: &SpatialVector<Real>,
         r1: &Vector<Real>,
         r2: &Vector<Real>,
-        basis: &Rotation<Real>,
+        basis1: &Rotation<Real>,
+        basis2: &Rotation<Real>,
         rb1: &RigidBody,
         rb2: &RigidBody,
     ) -> SpatialVector<Real> {
-        let lin_dvel = -rb1.linvel - rb1.angvel.gcross(*r1) + rb2.linvel + rb2.angvel.gcross(*r2);
-        let ang_dvel = -rb1.angvel + rb2.angvel;
-
-        let lin_dvel2 = basis.inverse_transform_vector(&lin_dvel);
-        let ang_dvel2 = basis.inverse_transform_vector(&ang_dvel);
+        let lin_dvel = basis1.inverse_transform_vector(&(-rb1.linvel - rb1.angvel.gcross(*r1)))
+            + basis2.inverse_transform_vector(&(rb2.linvel + rb2.angvel.gcross(*r2)));
+        let ang_dvel = basis1.inverse_transform_vector(&-rb1.angvel)
+            + basis2.inverse_transform_vector(&rb2.angvel);
 
         let min_linvel = min_velocity.xyz();
         let min_angvel = min_velocity.fixed_rows::<AngDim>(DIM).into_owned();
         let max_linvel = max_velocity.xyz();
         let max_angvel = max_velocity.fixed_rows::<AngDim>(DIM).into_owned();
-        let lin_rhs = lin_dvel2 - lin_dvel2.sup(&min_linvel).inf(&max_linvel);
-        let ang_rhs = ang_dvel2 - ang_dvel2.sup(&min_angvel).inf(&max_angvel);
+        let lin_rhs = lin_dvel - lin_dvel.sup(&min_linvel).inf(&max_linvel);
+        let ang_rhs = ang_dvel - ang_dvel.sup(&min_angvel).inf(&max_angvel);
 
         #[cfg(feature = "dim2")]
         return Vector3::new(lin_rhs.x, lin_rhs.y, ang_rhs);
@@ -120,6 +121,32 @@ impl GenericVelocityConstraint {
         }
     }
 
+    pub fn invert_partial_delassus_matrix(
+        min_impulse: &Vector<Real>,
+        max_impulse: &Vector<Real>,
+        dependant_set_mask: &mut Vector<Real>,
+        mut delassus: na::Matrix3<Real>,
+    ) -> na::Matrix3<Real> {
+        // Adjust the Delassus matrix to take force limits into account.
+        // If a DoF has a force limit, then we need to make its
+        // constraint independent from the others because otherwise
+        // the force clamping will cause errors to propagate in the
+        // other constraints.
+        for i in 0..3 {
+            if min_impulse[i] > -Real::MAX || max_impulse[i] < Real::MAX {
+                let diag = delassus[(i, i)];
+                delassus.column_mut(i).fill(0.0);
+                delassus.row_mut(i).fill(0.0);
+                delassus[(i, i)] = diag;
+                dependant_set_mask[i] = 0.0;
+            } else {
+                dependant_set_mask[i] = 1.0;
+            }
+        }
+
+        delassus.try_inverse().unwrap()
+    }
+
     pub fn compute_position_error(
         joint: &GenericJoint,
         anchor1: &Isometry<Real>,
@@ -169,32 +196,6 @@ impl GenericVelocityConstraint {
         }
     }
 
-    pub fn invert_partial_delassus_matrix(
-        min_impulse: &Vector<Real>,
-        max_impulse: &Vector<Real>,
-        dependant_set_mask: &mut Vector<Real>,
-        mut delassus: na::Matrix3<Real>,
-    ) -> na::Matrix3<Real> {
-        // Adjust the Delassus matrix to take force limits into account.
-        // If a DoF has a force limit, then we need to make its
-        // constraint independent from the others because otherwise
-        // the force clamping will cause errors to propagate in the
-        // other constraints.
-        for i in 0..3 {
-            if min_impulse[i] > -Real::MAX || max_impulse[i] < Real::MAX {
-                let diag = delassus[(i, i)];
-                delassus.column_mut(i).fill(0.0);
-                delassus.row_mut(i).fill(0.0);
-                delassus[(i, i)] = diag;
-                dependant_set_mask[i] = 0.0;
-            } else {
-                dependant_set_mask[i] = 1.0;
-            }
-        }
-
-        delassus.try_inverse().unwrap()
-    }
-
     pub fn from_params(
         params: &IntegrationParameters,
         joint_id: JointIndex,
@@ -204,7 +205,8 @@ impl GenericVelocityConstraint {
     ) -> Self {
         let anchor1 = rb1.position * joint.local_anchor1;
         let anchor2 = rb2.position * joint.local_anchor2;
-        let basis = anchor1.rotation;
+        let basis1 = anchor1.rotation;
+        let basis2 = anchor2.rotation;
         let im1 = rb1.effective_inv_mass;
         let im2 = rb2.effective_inv_mass;
         let ii1 = rb1.effective_world_inv_inertia_sqrt.squared();
@@ -219,7 +221,7 @@ impl GenericVelocityConstraint {
         let mut max_velocity = joint.max_velocity;
         let mut dependant_set_mask = SpacialVector::repeat(1.0);
 
-        let pos_rhs = Self::compute_position_error(joint, &anchor1, &anchor2, &basis)
+        let pos_rhs = Self::compute_position_error(joint, &anchor1, &anchor2, &basis1)
             * params.inv_dt()
             * params.joint_erp;
 
@@ -236,19 +238,28 @@ impl GenericVelocityConstraint {
             }
         }
 
-        let rhs =
-            Self::compute_velocity_error(&min_velocity, &max_velocity, &r1, &r2, &basis, rb1, rb2);
+        let rhs = Self::compute_velocity_error(
+            &min_velocity,
+            &max_velocity,
+            &r1,
+            &r2,
+            &basis1,
+            &basis2,
+            rb1,
+            rb2,
+        );
         let rhs_lin = rhs.xyz();
         let rhs_ang = rhs.fixed_rows::<Dim>(DIM).into();
 
         // TODO: we should keep the SdpMatrix3 type.
-        let rotmat = basis.to_rotation_matrix().into_inner();
-        let rmat1 = r1.gcross_matrix() * rotmat;
-        let rmat2 = r2.gcross_matrix() * rotmat;
+        let rotmat1 = basis1.to_rotation_matrix().into_inner();
+        let rotmat2 = basis2.to_rotation_matrix().into_inner();
+        let rmat1 = r1.gcross_matrix() * rotmat1;
+        let rmat2 = r2.gcross_matrix() * rotmat2;
         let delassus00 = (ii1.quadform(&rmat1).add_diagonal(im1)
             + ii2.quadform(&rmat2).add_diagonal(im2))
         .into_matrix();
-        let delassus11 = (ii1.quadform(&rotmat) + ii2.quadform(&rotmat)).into_matrix();
+        let delassus11 = (ii1.quadform(&rotmat1) + ii2.quadform(&rotmat2)).into_matrix();
 
         let inv_lhs_lin = GenericVelocityConstraint::invert_partial_delassus_matrix(
             &min_pos_impulse.xyz(),
@@ -288,7 +299,8 @@ impl GenericVelocityConstraint {
             inv_lhs_ang,
             r1,
             r2,
-            basis,
+            basis1,
+            basis2,
             dependant_set_mask,
             vel: GenericConstraintPart {
                 lin_impulse,
@@ -307,21 +319,20 @@ impl GenericVelocityConstraint {
         let mut mj_lambda1 = mj_lambdas[self.mj_lambda1 as usize];
         let mut mj_lambda2 = mj_lambdas[self.mj_lambda2 as usize];
 
-        let lin_impulse = self.basis * self.vel.lin_impulse;
-        #[cfg(feature = "dim2")]
-        let ang_impulse = self.basis * self.vel.impulse[2];
-        #[cfg(feature = "dim3")]
-        let ang_impulse = self.basis * self.vel.ang_impulse;
+        let lin_impulse1 = self.basis1 * self.vel.lin_impulse;
+        let ang_impulse1 = self.basis1 * self.vel.ang_impulse;
+        let lin_impulse2 = self.basis2 * self.vel.lin_impulse;
+        let ang_impulse2 = self.basis2 * self.vel.ang_impulse;
 
-        mj_lambda1.linear += self.im1 * lin_impulse;
+        mj_lambda1.linear += self.im1 * lin_impulse1;
         mj_lambda1.angular += self
             .ii1_sqrt
-            .transform_vector(ang_impulse + self.r1.gcross(lin_impulse));
+            .transform_vector(ang_impulse1 + self.r1.gcross(lin_impulse1));
 
-        mj_lambda2.linear -= self.im2 * lin_impulse;
+        mj_lambda2.linear -= self.im2 * lin_impulse2;
         mj_lambda2.angular -= self
             .ii2_sqrt
-            .transform_vector(ang_impulse + self.r2.gcross(lin_impulse));
+            .transform_vector(ang_impulse2 + self.r2.gcross(lin_impulse2));
 
         mj_lambdas[self.mj_lambda1 as usize] = mj_lambda1;
         mj_lambdas[self.mj_lambda2 as usize] = mj_lambda2;
@@ -441,6 +452,7 @@ impl GenericVelocityGroundConstraint {
             &r1,
             &r2,
             &basis,
+            &basis,
             rb1,
             rb2,
         );
@@ -585,28 +597,30 @@ impl GenericConstraintPart {
             let ang_vel1 = parent.ii1_sqrt.transform_vector(mj_lambda1.angular);
             let ang_vel2 = parent.ii2_sqrt.transform_vector(mj_lambda2.angular);
 
-            let dvel = parent.basis.inverse_transform_vector(
-                &(-mj_lambda1.linear - ang_vel1.gcross(parent.r1)
-                    + mj_lambda2.linear
-                    + ang_vel2.gcross(parent.r2)),
-            );
+            let dvel = parent
+                .basis1
+                .inverse_transform_vector(&(-mj_lambda1.linear - ang_vel1.gcross(parent.r1)))
+                + parent
+                    .basis2
+                    .inverse_transform_vector(&(mj_lambda2.linear + ang_vel2.gcross(parent.r2)));
 
             let err = dvel + self.rhs_lin;
 
             new_lin_impulse = (self.lin_impulse + parent.inv_lhs_lin * err)
                 .sup(&self.min_lin_impulse)
                 .inf(&self.max_lin_impulse);
-            let effective_impulse = parent.basis * (new_lin_impulse - self.lin_impulse);
+            let effective_impulse1 = parent.basis1 * (new_lin_impulse - self.lin_impulse);
+            let effective_impulse2 = parent.basis2 * (new_lin_impulse - self.lin_impulse);
 
-            mj_lambda1.linear += parent.im1 * effective_impulse;
+            mj_lambda1.linear += parent.im1 * effective_impulse1;
             mj_lambda1.angular += parent
                 .ii1_sqrt
-                .transform_vector(parent.r1.gcross(effective_impulse));
+                .transform_vector(parent.r1.gcross(effective_impulse1));
 
-            mj_lambda2.linear -= parent.im2 * effective_impulse;
+            mj_lambda2.linear -= parent.im2 * effective_impulse2;
             mj_lambda2.angular -= parent
                 .ii2_sqrt
-                .transform_vector(parent.r2.gcross(effective_impulse));
+                .transform_vector(parent.r2.gcross(effective_impulse2));
         }
 
         /*
@@ -618,18 +632,18 @@ impl GenericConstraintPart {
             let ang_vel1 = parent.ii1_sqrt.transform_vector(mj_lambda1.angular);
             let ang_vel2 = parent.ii2_sqrt.transform_vector(mj_lambda2.angular);
 
-            let dvel = parent
-                .basis
-                .inverse_transform_vector(&(ang_vel2 - ang_vel1));
+            let dvel = parent.basis2.inverse_transform_vector(&ang_vel2)
+                - parent.basis1.inverse_transform_vector(&ang_vel1);
             let err = dvel + self.rhs_ang;
 
             new_ang_impulse = (self.ang_impulse + parent.inv_lhs_ang * err)
                 .sup(&self.min_ang_impulse)
                 .inf(&self.max_ang_impulse);
-            let effective_impulse = parent.basis * (new_ang_impulse - self.ang_impulse);
+            let effective_impulse1 = parent.basis1 * (new_ang_impulse - self.ang_impulse);
+            let effective_impulse2 = parent.basis2 * (new_ang_impulse - self.ang_impulse);
 
-            mj_lambda1.angular += parent.ii1_sqrt.transform_vector(effective_impulse);
-            mj_lambda2.angular -= parent.ii2_sqrt.transform_vector(effective_impulse);
+            mj_lambda1.angular += parent.ii1_sqrt.transform_vector(effective_impulse1);
+            mj_lambda2.angular -= parent.ii2_sqrt.transform_vector(effective_impulse2);
         }
 
         (new_lin_impulse, new_ang_impulse)
diff --git a/src/dynamics/solver/joint_constraint/joint_constraint.rs b/src/dynamics/solver/joint_constraint/joint_constraint.rs
index 12b8f77..ebc3c4a 100644
--- a/src/dynamics/solver/joint_constraint/joint_constraint.rs
+++ b/src/dynamics/solver/joint_constraint/joint_constraint.rs
@@ -14,9 +14,9 @@ use super::{
 #[cfg(feature = "dim3")]
 #[cfg(feature = "simd-is-enabled")]
 use super::{WRevoluteVelocityConstraint, WRevoluteVelocityGroundConstraint};
-use crate::dynamics::solver::joint_constraint::generic_velocity_constraint::{
-    GenericVelocityConstraint, GenericVelocityGroundConstraint,
-};
+// use crate::dynamics::solver::joint_constraint::generic_velocity_constraint::{
+//     GenericVelocityConstraint, GenericVelocityGroundConstraint,
+// };
 use crate::dynamics::solver::DeltaVel;
 use crate::dynamics::{
     IntegrationParameters, Joint, JointGraphEdge, JointIndex, JointParams, RigidBodySet,
@@ -38,12 +38,12 @@ pub(crate) enum AnyJointVelocityConstraint {
     WFixedConstraint(WFixedVelocityConstraint),
     #[cfg(feature = "simd-is-enabled")]
     WFixedGroundConstraint(WFixedVelocityGroundConstraint),
-    GenericConstraint(GenericVelocityConstraint),
-    GenericGroundConstraint(GenericVelocityGroundConstraint),
-    #[cfg(feature = "simd-is-enabled")]
-    WGenericConstraint(WGenericVelocityConstraint),
-    #[cfg(feature = "simd-is-enabled")]
-    WGenericGroundConstraint(WGenericVelocityGroundConstraint),
+    // GenericConstraint(GenericVelocityConstraint),
+    // GenericGroundConstraint(GenericVelocityGroundConstraint),
+    // #[cfg(feature = "simd-is-enabled")]
+    // WGenericConstraint(WGenericVelocityConstraint),
+    // #[cfg(feature = "simd-is-enabled")]
+    // WGenericGroundConstraint(WGenericVelocityGroundConstraint),
     PrismaticConstraint(PrismaticVelocityConstraint),
     PrismaticGroundConstraint(PrismaticVelocityGroundConstraint),
     #[cfg(feature = "simd-is-enabled")]
@@ -89,9 +89,9 @@ impl AnyJointVelocityConstraint {
             JointParams::PrismaticJoint(p) => AnyJointVelocityConstraint::PrismaticConstraint(
                 PrismaticVelocityConstraint::from_params(params, joint_id, rb1, rb2, p),
             ),
-            JointParams::GenericJoint(p) => AnyJointVelocityConstraint::GenericConstraint(
-                GenericVelocityConstraint::from_params(params, joint_id, rb1, rb2, p),
-            ),
+            // JointParams::GenericJoint(p) => AnyJointVelocityConstraint::GenericConstraint(
+            //     GenericVelocityConstraint::from_params(params, joint_id, rb1, rb2, p),
+            // ),
             #[cfg(feature = "dim3")]
             JointParams::RevoluteJoint(p) => AnyJointVelocityConstraint::RevoluteConstraint(
                 RevoluteVelocityConstraint::from_params(params, joint_id, rb1, rb2, p),
@@ -167,11 +167,11 @@ impl AnyJointVelocityConstraint {
             JointParams::FixedJoint(p) => AnyJointVelocityConstraint::FixedGroundConstraint(
                 FixedVelocityGroundConstraint::from_params(params, joint_id, rb1, rb2, p, flipped),
             ),
-            JointParams::GenericJoint(p) => AnyJointVelocityConstraint::GenericGroundConstraint(
-                GenericVelocityGroundConstraint::from_params(
-                    params, joint_id, rb1, rb2, p, flipped,
-                ),
-            ),
+            // JointParams::GenericJoint(p) => AnyJointVelocityConstraint::GenericGroundConstraint(
+            //     GenericVelocityGroundConstraint::from_params(
+            //         params, joint_id, rb1, rb2, p, flipped,
+            //     ),
+            // ),
             JointParams::PrismaticJoint(p) => {
                 AnyJointVelocityConstraint::PrismaticGroundConstraint(
                     PrismaticVelocityGroundConstraint::from_params(
@@ -180,10 +180,8 @@ impl AnyJointVelocityConstraint {
                 )
             }
             #[cfg(feature = "dim3")]
-            JointParams::RevoluteJoint(p) => AnyJointVelocityConstraint::RevoluteGroundConstraint(
-                RevoluteVelocityGroundConstraint::from_params(
-                    params, joint_id, rb1, rb2, p, flipped,
-                ),
+            JointParams::RevoluteJoint(p) => RevoluteVelocityGroundConstraint::from_params(
+                params, joint_id, rb1, rb2, p, flipped,
             ),
         }
     }
@@ -267,12 +265,12 @@ impl AnyJointVelocityConstraint {
             AnyJointVelocityConstraint::WFixedConstraint(c) => c.warmstart(mj_lambdas),
             #[cfg(feature = "simd-is-enabled")]
             AnyJointVelocityConstraint::WFixedGroundConstraint(c) => c.warmstart(mj_lambdas),
-            AnyJointVelocityConstraint::GenericConstraint(c) => c.warmstart(mj_lambdas),
-            AnyJointVelocityConstraint::GenericGroundConstraint(c) => c.warmstart(mj_lambdas),
-            #[cfg(feature = "simd-is-enabled")]
-            AnyJointVelocityConstraint::WGenericConstraint(c) => c.warmstart(mj_lambdas),
-            #[cfg(feature = "simd-is-enabled")]
-            AnyJointVelocityConstraint::WGenericGroundConstraint(c) => c.warmstart(mj_lambdas),
+            // AnyJointVelocityConstraint::GenericConstraint(c) => c.warmstart(mj_lambdas),
+            // AnyJointVelocityConstraint::GenericGroundConstraint(c) => c.warmstart(mj_lambdas),
+            // #[cfg(feature = "simd-is-enabled")]
+            // AnyJointVelocityConstraint::WGenericConstraint(c) => c.warmstart(mj_lambdas),
+            // #[cfg(feature = "simd-is-enabled")]
+            // AnyJointVelocityConstraint::WGenericGroundConstraint(c) => c.warmstart(mj_lambdas),
             AnyJointVelocityConstraint::PrismaticConstraint(c) => c.warmstart(mj_lambdas),
             AnyJointVelocityConstraint::PrismaticGroundConstraint(c) => c.warmstart(mj_lambdas),
             #[cfg(feature = "simd-is-enabled")]
@@ -307,12 +305,12 @@ impl AnyJointVelocityConstraint {
             AnyJointVelocityConstraint::WFixedConstraint(c) => c.solve(mj_lambdas),
             #[cfg(feature = "simd-is-enabled")]
             AnyJointVelocityConstraint::WFixedGroundConstraint(c) => c.solve(mj_lambdas),
-            AnyJointVelocityConstraint::GenericConstraint(c) => c.solve(mj_lambdas),
-            AnyJointVelocityConstraint::GenericGroundConstraint(c) => c.solve(mj_lambdas),
-            #[cfg(feature = "simd-is-enabled")]
-            AnyJointVelocityConstraint::WGenericConstraint(c) => c.solve(mj_lambdas),
-            #[cfg(feature = "simd-is-enabled")]
-            AnyJointVelocityConstraint::WGenericGroundConstraint(c) => c.solve(mj_lambdas),
+            // AnyJointVelocityConstraint::GenericConstraint(c) => c.solve(mj_lambdas),
+            // AnyJointVelocityConstraint::GenericGroundConstraint(c) => c.solve(mj_lambdas),
+            // #[cfg(feature = "simd-is-enabled")]
+            // AnyJointVelocityConstraint::WGenericConstraint(c) => c.solve(mj_lambdas),
+            // #[cfg(feature = "simd-is-enabled")]
+            // AnyJointVelocityConstraint::WGenericGroundConstraint(c) => c.solve(mj_lambdas),
             AnyJointVelocityConstraint::PrismaticConstraint(c) => c.solve(mj_lambdas),
             AnyJointVelocityConstraint::PrismaticGroundConstraint(c) => c.solve(mj_lambdas),
             #[cfg(feature = "simd-is-enabled")]
@@ -355,16 +353,16 @@ impl AnyJointVelocityConstraint {
             AnyJointVelocityConstraint::WFixedGroundConstraint(c) => {
                 c.writeback_impulses(joints_all)
             }
-            AnyJointVelocityConstraint::GenericConstraint(c) => c.writeback_impulses(joints_all),
-            AnyJointVelocityConstraint::GenericGroundConstraint(c) => {
-                c.writeback_impulses(joints_all)
-            }
-            #[cfg(feature = "simd-is-enabled")]
-            AnyJointVelocityConstraint::WGenericConstraint(c) => c.writeback_impulses(joints_all),
-            #[cfg(feature = "simd-is-enabled")]
-            AnyJointVelocityConstraint::WGenericGroundConstraint(c) => {
-                c.writeback_impulses(joints_all)
-            }
+            // AnyJointVelocityConstraint::GenericConstraint(c) => c.writeback_impulses(joints_all),
+            // AnyJointVelocityConstraint::GenericGroundConstraint(c) => {
+            //