Tweak some physics, try to reduce pitch stabilization.

src/action/components.rs

@@ -85,7 +85,7 @@ impl Default for CatControllerState {
             pitch_prev: Default::default(),
             decay_factor: 0.99,
             roll_limit: 1.5,
-            pitch_limit: 0.2,
+            pitch_limit: 0.1,
         }
     }
 }

src/action/systems.rs

@@ -48,10 +48,10 @@ pub(super) fn falling_cat(
     let wright = xform.forward().cross(wup).normalize();
 
     let roll_error = wright.dot(bike_up);
-    let pitch_error = wup.dot(xform.back()) * PITCH_SCALE;
+    let pitch_error = wup.dot(xform.back());
 
     // only try to correct roll if we're not totally vertical
-    if pitch_error.abs() < 0.8 {
+    if pitch_error.abs() < 0.95 {
         let (derivative, integral) = control_vars.update_roll(roll_error, time.delta_seconds());
         let mag =
             (settings.kp * roll_error) + (settings.ki * integral) + (settings.kd * derivative);
@@ -61,17 +61,20 @@ pub(super) fn falling_cat(
     }
 
     // we can do pitch correction any time, it's not coupled to roll
-    let (derivative, integral) = control_vars.update_pitch(pitch_error, time.delta_seconds());
+    let scaled_pitch_error = pitch_error * PITCH_SCALE;
-    let mag = (settings.kp * pitch_error) + (settings.ki * integral) + (settings.kd * derivative);
+    let (derivative, integral) =
+        control_vars.update_pitch(scaled_pitch_error, time.delta_seconds());
+    let mag =
+        (settings.kp * scaled_pitch_error) + (settings.ki * integral) + (settings.kd * derivative);
     if mag.is_finite() {
-        forces.torque += wright * mag * 0.25;
+        forces.torque += wright * mag;
     }
 
     #[cfg(feature = "inspector")]
     {
         let now = Instant::now();
-        if (now - debug_instant.0).as_millis() > 500 {
+        if (now - debug_instant.0).as_millis() > 1000 {
-            dbg!(roll_error, pitch_error, &control_vars, mag);
+            dbg!(&control_vars, mag);
             debug_instant.0 = now;
         }
     }
@@ -99,7 +102,7 @@ pub(super) fn input_forces(
 
     // brake
     for mut motor in braking_query.iter_mut() {
-        let factor = if input.brake { 100.00 } else { 0.0 };
+        let factor = if input.brake { 200.00 } else { 0.0 };
         motor.data = (*motor
             .data
             .as_revolute_mut()

src/bike/components.rs

@@ -23,6 +23,8 @@ pub struct WheelConfig {
     pub stiffness: f32,
     pub damping: f32,
     pub radius: f32,
+    pub friction: f32,
+    pub restitution: f32,
 }
 
 impl Default for WheelConfig {
@@ -36,6 +38,8 @@ impl Default for WheelConfig {
             stiffness: 90.0,
             damping: 8.0,
             radius: 0.3,
+            friction: 0.9,
+            restitution: 0.8,
         }
     }
 }

src/bike/wheels.rs

@@ -47,8 +47,8 @@ pub fn spawn_tires(
     };
 
     let friction = Friction {
-        coefficient: 0.8,
+        coefficient: conf.friction,
-        combine_rule: CoefficientCombineRule::Min,
+        combine_rule: CoefficientCombineRule::Average,
     };
 
     let mut wheel_poses = Vec::with_capacity(2);
@@ -86,24 +86,25 @@ pub fn spawn_tires(
         let fork_rb_entity = commands
             .spawn(RigidBody::Dynamic)
             .insert(prismatic_joint)
+            .insert(not_sleeping)
             .id();
 
-        let axel_parent = if let Some(steering) = steering {
+        let axel_parent_entity = if let Some(steering) = steering {
             let neck_builder = RevoluteJointBuilder::new(Vec3::Y);
             let neck_joint = MultibodyJoint::new(fork_rb_entity, neck_builder);
-            let hub = commands
+            let neck = commands
                 .spawn(RigidBody::Dynamic)
                 .insert(neck_joint)
                 .insert(steering)
+                .insert(not_sleeping)
                 .id();
-            dbg!(hub);
+            neck
-            hub
         } else {
             fork_rb_entity
         };
 
         let revolute_builder = RevoluteJointBuilder::new(Vec3::X);
-        let axel_joint = MultibodyJoint::new(axel_parent, revolute_builder);
+        let axel_joint = MultibodyJoint::new(axel_parent_entity, revolute_builder);
 
         commands.spawn(pbr_bundle.clone()).insert((
             wheel_collider,
@@ -116,7 +117,7 @@ pub fn spawn_tires(
             friction,
             CyberWheel,
             ExternalForce::default(),
-            Restitution::new(0.2),
+            Restitution::new(conf.restitution),
             SpatialBundle::default(),
             TransformInterpolation::default(),
             RigidBody::Dynamic,