feat: physics tweaks

godot/car_player.tscn

@@ -8,7 +8,7 @@
 [ext_resource type="PackedScene" uid="uid://6qwqncti3xr2" path="res://Models/CarParts/SM_Veh_Hatch_01_Fenders_02.fbx" id="6_xu64x"]
 
 [sub_resource type="Curve" id="Curve_dpk6q"]
-_data = [Vector2(0.962441, 0), 0.0, 0.0, 0, 0, Vector2(1, 1), 0.0, 0.0, 0, 0]
+_data = [Vector2(0.962441, 0), 0.0, 0.0, 0, 0, Vector2(1, 0.32967), 0.0, 0.0, 0, 0]
 point_count = 2
 
 [sub_resource type="Curve" id="Curve_htvme"]
@@ -34,7 +34,6 @@ oversteer_curve = SubResource("Curve_dpk6q")
 oversteer_curve_x_scale = 40.0
 understeer_curve = SubResource("Curve_htvme")
 understeer_curve_x_scale = 40.0
-traction_recovery_speed = 20.0
 collision_layer = 7
 collision_mask = 3
 mass = 1000.0
@@ -45,9 +44,12 @@ custom_integrator = true
 continuous_cd = true
 max_contacts_reported = 128
 contact_monitor = true
+linear_damp_mode = 1
+linear_damp = 0.5
 
 [node name="Camera3D" type="Camera3D" parent="."]
-transform = Transform3D(-1, -1.36051e-08, -8.63576e-08, -2.87879e-08, 0.983969, 0.178338, 8.25469e-08, 0.178338, -0.983969, 4.58152e-07, 1.76689, -2.8478)
+transform = Transform3D(-1, -2.02334e-08, -8.50491e-08, -2.87879e-08, 0.994803, 0.10182, 8.25469e-08, 0.10182, -0.994803, 4.6449e-07, 2.24116, -4.7912)
+fov = 68.9128
 
 [node name="Body" type="CollisionShape3D" parent="."]
 transform = Transform3D(1, 0, 0, 0, -4.37114e-08, -1, 0, 1, -4.37114e-08, 0, 0.687824, 0.174572)

src/car_physics.cpp

@@ -52,7 +52,7 @@ void CarPhysics::process_oversteer(double delta_time) {
     float const target = this->current_steering == 0.f
         ? 0.f
         : (this->evaluate_oversteer_curve(this->local_velocity.z) + (this->brake ? this->handbrake_oversteer : 0.f)) * Math::sign(this->current_steering);
-    if(Math::abs(target) >=  Math::abs(this->current_oversteer) && Math::sign(target) == Math::sign(this->current_oversteer))
+    if(target != 0.f && Math::abs(target) >= Math::abs(this->current_oversteer) && Math::sign(target) == Math::sign(this->current_oversteer))
         this->current_oversteer = target;
     else
         this->current_oversteer = Math::move_toward(this->current_oversteer, target, float(delta_time * this->traction_recovery_speed));
@@ -77,15 +77,15 @@ void CarPhysics::_integrate_forces(PhysicsDirectBodyState3D *state) {
     this->last_velocity = state->get_linear_velocity();
     state->set_linear_velocity(
             (this->is_grounded()
-                ? (this->local_to_world_velocity() + Vector3{0, float(-9.8f * state->get_step()), 0})
+                ? (this->local_to_world_velocity() + Vector3{0, -0.05f, 0})
                 : (this->get_linear_velocity() + Vector3{0, float(-9.8f * state->get_step()), 0})));
 }
 
 void CarPhysics::integrate_steering(PhysicsDirectBodyState3D *state) {
     float target_x_velocity = 0.f;
     if(this->local_velocity.z != 0.f) {
-        Vector3 const steering_angle_vel = this->get_global_basis().get_column(1) * (
-                this->current_steering * Math::sign(this->local_velocity.z + this->current_oversteer * this->oversteer_steering_speed));
+        Vector3 const steering_angle_vel = this->get_global_basis().get_column(1) *
+            (this->current_steering * Math::sign(this->local_velocity.z) + this->current_oversteer * this->oversteer_steering_speed);
         state->set_angular_velocity(steering_angle_vel * (1.0f-this->current_understeer));
         target_x_velocity = this->current_steering * this->steering_inward_speed;
     } else {
@@ -104,17 +104,12 @@ void CarPhysics::integrate_engine_acceleration(PhysicsDirectBodyState3D *state)
         this->local_velocity.z = 0.f;
     }
 
-    this->local_velocity.z = Math::move_toward(
-            this->local_velocity.z,
-            this->get_true_target_speed(),
-            float(this->get_current_acceleration() * state->get_step()));
+    this->local_velocity.z = Math::move_toward(this->local_velocity.z, this->get_true_target_speed(), float(this->get_current_acceleration() * state->get_step()));
 }
 
 void CarPhysics::integrate_oversteer(PhysicsDirectBodyState3D *state) {
-    this->local_velocity.x = Math::clamp(
-        this->local_velocity.x - this->local_velocity.z * this->current_oversteer * this->slide_speed_acceleration,
-        -this->max_slide_speed,
-        this->max_slide_speed);
+    this->local_velocity.x = Math::clamp(this->local_velocity.x - this->local_velocity.z * this->current_oversteer * this->slide_speed_acceleration,
+                                         -this->max_slide_speed, this->max_slide_speed);
 }
 
 void CarPhysics::on_body_shape_entered(RID body_rid, Node *body, int body_shape_index, int local_shape_index) {

src/car_physics.hpp

@@ -93,7 +93,7 @@ private:
     float engine_brake_force{30.f};
     float handbrake_force{40.f};
     float handbrake_oversteer{1.f};
-    float traction_recovery_speed{100.f};
+    float traction_recovery_speed{1.f};
     float max_slide_speed{20.f};
     float slide_speed_acceleration{0.05f};
     float oversteer_speed_penalty{5.f};

src/car_player.hpp

@@ -25,7 +25,7 @@ private:
 
     const float max_speed{40.f};
     const float max_speed_reverse{10.f};
-    const float steering_factor{2.f};
+    const float steering_factor{0.7f};
 };
 };