Shot curve using a simulated Magnus effect

levels/debug_level/debug_level.tscn

@@ -341,16 +341,16 @@ transform = Transform3D(-0.734269, 0.305072, -0.606448, 0, 0.893336, 0.44939, 0.
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 129.404, -9.53674e-07, 309.4)
 
 [node name="ConcreteBuilding1" parent="CityBuildings" instance=ExtResource("10_lf15j")]
-transform = Transform3D(-4.37114e-08, 0, 1, 0, 1, 0, -1, 0, -4.37114e-08, 0, 0, 0)
+transform = Transform3D(-4.37114e-08, 0, 1, 0, 1, 0, -1, 0, -4.37114e-08, 0, -0.01, 0)
 
 [node name="KanaSignboard" parent="CityBuildings/ConcreteBuilding1" instance=ExtResource("11_evxup")]
 transform = Transform3D(-8.74228e-08, 0, -2, 0, 2, 0, 2, 0, -8.74228e-08, 10.8, 12, 7)
 
 [node name="ConcreteBuilding2" parent="CityBuildings" instance=ExtResource("10_lf15j")]
-transform = Transform3D(-4.37114e-08, 0, -1, 0, 1, 0, 1, 0, -4.37114e-08, 0, 0, 20)
+transform = Transform3D(-4.37114e-08, 0, -1, 0, 1, 0, 1, 0, -4.37114e-08, 0, -0.01, 20)
 
 [node name="ConcreteBuilding3" parent="CityBuildings" instance=ExtResource("10_lf15j")]
-transform = Transform3D(-4.37114e-08, 0, -1, 0, 1, 0, 1, 0, -4.37114e-08, 0, 0, 40)
+transform = Transform3D(-4.37114e-08, 0, -1, 0, 1, 0, 1, 0, -4.37114e-08, 0, -0.01, 40)
 
 [node name="PalmTree" parent="CityBuildings" instance=ExtResource("12_sswxf")]
 transform = Transform3D(-0.69799, 0, -0.716107, 0, 1, 0, 0.716107, 0, -0.69799, 11.468, 0, -12.468)
@@ -370,7 +370,7 @@ transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 137.181, -20, -7.285)
 curve = SubResource("Curve3D_5n8tb")
 
 [node name="ConcreteBuilding1" parent="MountainCurve" instance=ExtResource("10_lf15j")]
-transform = Transform3D(-0.0979477, 0, 0.995192, 0, 1, 0, -0.995192, 0, -0.0979477, -10.074, 0, -32.347)
+transform = Transform3D(-0.0979477, 0, 0.995192, 0, 1, 0, -0.995192, 0, -0.0979477, -10.074, -0.01, -32.347)
 
 [node name="GuardRail" parent="MountainCurve" instance=ExtResource("16_xtxyj")]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 70.2122, 0, 116.269)

src/equipment/balls/physics_ball/game_ball.gd

@@ -12,6 +12,7 @@ enum Type {
 }
 
 const TERRAIN_DAMPING_EPSILON := 1e-6
+const MAGNUS_EPSILON := 1e-3
 const IRON_DAMPING := 9999.0
 
 ## Angular damping while in air
@@ -21,6 +22,16 @@ const IRON_DAMPING := 9999.0
 ## Angular damping for iron balls
 @export var iron_damping := 9999.0
 
+#@export var fluid_density := 1.225
+#@export var lift_coefficient := 0.05
+#@export var radius := 0.05
+## Coefficient of angular velocity influence on linear velocity
+## This is approximately 1/2 * rho * C_L * pi * r^2
+## where `rho` is the fluid density of the medium, or 1.225 for air at sea level,
+## and `C_L` is the lift coefficient which for our purposes is 0.05,
+## and `r` is the radius of the ball, which is 5cm.
+@export var magnus_coefficient := 0.00024
+
 ## Causes the ball to act more like a brick
 @export var iron_ball := false:
 	set(value):
@@ -59,16 +70,31 @@ func _total_terrain_angular_damping() -> float:
 	)
 
 
+func _magnus_force() -> Vector3:
+	return magnus_coefficient * angular_velocity.cross(linear_velocity)
+
+
 func _integrate_forces(state: PhysicsDirectBodyState3D) -> void:
 	if not _awake:
 		# Triggered on first frame after waking
 		_awake = true
 		_position_on_last_wake = global_position
 		_last_contact_normal = Vector3.UP
+		# TODO something's fucky here... I think this gets called once after the ball sleeps
 
 	var damping := air_damping
 	if state.get_contact_count():
-		_last_contact_normal = state.get_contact_local_normal(0)
+		constant_force = Vector3.ZERO
+
+		# We want the contact normal which minimizes the angle to the up vector
+		var min_dot := -1.0
+		for i: int in range(state.get_contact_count()):
+			var norm := state.get_contact_local_normal(i)
+			var dot := norm.dot(Vector3.UP)
+			if dot > min_dot:
+				min_dot = dot
+				_last_contact_normal = norm
+
 		damping = _total_terrain_angular_damping()
 		if damping <= TERRAIN_DAMPING_EPSILON:
 			damping = rough_damping
@@ -77,6 +103,13 @@ func _integrate_forces(state: PhysicsDirectBodyState3D) -> void:
 	angular_damp = damping
 
 
+func _physics_process(_delta: float) -> void:
+	# Simulate magnus effect
+	var magnus := _magnus_force()
+	if magnus.length_squared() > MAGNUS_EPSILON:
+		apply_central_force(magnus)
+
+
 func enter_zone(zone: BallZone) -> void:
 	_zones.push_back(zone)
 

src/equipment/balls/physics_ball/physics_ball.tscn

@@ -34,8 +34,13 @@ script/source = "extends Control
 const COLOR_X := Color(1, 0, 0)
 const COLOR_Y := Color(0, 1, 0)
 const COLOR_Z := Color(0, 0, 1)
+const COLOR_MAGNUS := Color.CYAN
+const MAGNUS_SCALE := 3
 const WIDTH := 4
 
+@export var draw_reoriented_basis := true
+@export var draw_magnus_effect := true
+
 @onready var physics_ball: GameBall = $\"..\"
 
 
@@ -45,9 +50,9 @@ func _process(_delta: float) -> void:
 
 
 func _draw() -> void:
-	if physics_ball._last_contact_normal != null:
 	var camera := get_viewport().get_camera_3d()
 	var start := camera.unproject_position(physics_ball.global_position)
+	if draw_reoriented_basis and physics_ball._last_contact_normal != null:
 		var basis := physics_ball.get_reoriented_basis()
 		var end_x := camera.unproject_position(physics_ball.global_position + basis.x)
 		var end_y := camera.unproject_position(physics_ball.global_position + basis.y)
@@ -55,6 +60,10 @@ func _draw() -> void:
 		draw_line(start, end_x, COLOR_X, WIDTH)
 		draw_line(start, end_y, COLOR_Y, WIDTH)
 		draw_line(start, end_z, COLOR_Z, WIDTH)
+
+	if draw_magnus_effect:
+		var end := camera.unproject_position(physics_ball.global_position + physics_ball._magnus_force() * MAGNUS_SCALE)
+		draw_line(start, end, COLOR_MAGNUS, WIDTH)
 "
 
 [node name="PhysicsBall" type="RigidBody3D"]
@@ -63,7 +72,7 @@ physics_material_override = ExtResource("1_l23pw")
 freeze = true
 continuous_cd = true
 contact_monitor = true
-max_contacts_reported = 1
+max_contacts_reported = 3
 linear_damp_mode = 1
 angular_damp_mode = 1
 angular_damp = 8.0
@@ -86,5 +95,6 @@ anchor_bottom = 1.0
 grow_horizontal = 2
 grow_vertical = 2
 script = SubResource("GDScript_p4v7o")
+draw_reoriented_basis = false
 
 [connection signal="sleeping_state_changed" from="." to="." method="_on_sleeping_state_changed"]

src/player/shot_setup/shot_setup.gd

@@ -35,6 +35,12 @@ const BIG_POWER_THRESHOLD := 0.7
 ## Amount of life lost when landing in water
 const WATER_DAMAGE := 10.0
 
+## Angle of influence that shot curve has, in radians
+const CURVE_INFLUENCE := PI / 8
+
+## Maximum absolute curve for the "nice shot" animation to play
+const NICE_THRESHOLD := 0.2
+
 ## In Driving Range mode, the ball can be retrieved in the shot phase.
 @export var driving_range := false
 
@@ -108,7 +114,7 @@ var shot_curve: float:
 	set(value):
 		hud.curve_bar.value = value
 	get:
-		return hud.power_bar.value
+		return hud.curve_bar.value
 
 var game_ball: GameBall:
 	get:
@@ -231,12 +237,22 @@ func take_shot() -> void:
 
 	print_debug("WHACK!\nPower: ", shot_power, "\nCurve: ", shot_curve)
 
+	# Momentary impulse applied to the ball
 	var impulse := get_shot_impulse(shot_power)
 	print_debug("Shot impulse: ", impulse, "; ", impulse.length(), " N*s")
 
+	var curve := shot_ref.global_basis.x.normalized() * shot_curve
+
+	# Position where the ball is hit (imparts spin)
+	var offset := curve * 0.001
+	print_debug("Shot offset: ", offset, "; ", offset.length(), " m")
+	# Rotate impulse
+	impulse = impulse.rotated(Vector3.UP, -shot_curve * CURVE_INFLUENCE)
+
 	if game_ball:
+		game_ball.iron_ball = club == Club.Type.IRON
 		game_ball.freeze = false
-		game_ball.apply_central_impulse(impulse)
+		game_ball.apply_impulse(impulse, offset)
 
 	# Use a ball if a limited type is selected
 	if player.get_balls(ball_type) > 0:
@@ -354,8 +370,6 @@ func _on_club_change(new_club_type: Club.Type) -> void:
 	wedge_arrow.hide()
 	iron_arrow.hide()
 	putt_arrow.hide()
-	if game_ball:
-		game_ball.iron_ball = false
 	hud.club_selector.value = new_club_type
 	# TODO club change animation
 	character.hold_right(new_club.get_model())
@@ -372,8 +386,6 @@ func _on_club_change(new_club_type: Club.Type) -> void:
 		Club.Type.IRON:
 			shot_ref = iron_ref
 			iron_arrow.show()
-			if game_ball:
-				game_ball.iron_ball = true
 		Club.Type.SPECIAL:
 			# TODO figure this out
 			shot_ref = drive_ref
@@ -410,6 +422,10 @@ func _on_phase_change(new_phase: Phase) -> void:
 			hud.power_bar.hide()
 			hud.curve_bar.hide()
 
+			if perfect_aim:
+				shot_curve = 0.0
+
+			if abs(shot_curve) <= NICE_THRESHOLD:
 				hud.play_nice_animation()
 
 			if not driving_range:
@@ -426,7 +442,6 @@ func _on_phase_change(new_phase: Phase) -> void:
 
 func _on_game_ball_changed(ball: GameBall) -> void:
 	if ball:
-		ball.iron_ball = (club == Club.Type.IRON)
 		ball.entered_water.connect(_on_ball_entered_water)
 		ball.sleeping_state_changed.connect(_on_ball_sleeping_state_changed)
 

src/ui/shot_hud/ball_selector/ball_selector.tscn

@@ -43,14 +43,10 @@ texture = SubResource("GradientTexture2D_tm61r")
 [node name="BallList" type="VBoxContainer" parent="GradientMask"]
 unique_name_in_owner = true
 custom_minimum_size = Vector2(120, 0)
-layout_mode = 1
-anchors_preset = 15
-anchor_right = 1.0
-anchor_bottom = 1.0
+layout_mode = 0
 offset_top = 50.0
-offset_bottom = 50.0
-grow_horizontal = 2
-grow_vertical = 2
+offset_right = 120.0
+offset_bottom = 109.0
 theme_override_constants/separation = 5
 
 [node name="BasicIcon" parent="GradientMask/BallList" instance=ExtResource("1_1v8xg")]

src/ui/shot_hud/shot_hud.tscn

@@ -441,26 +441,26 @@ length = 0.001
 tracks/0/type = "value"
 tracks/0/imported = false
 tracks/0/enabled = true
-tracks/0/path = NodePath("SouthWest:position")
+tracks/0/path = NodePath("SouthWest:visible")
 tracks/0/interp = 1
 tracks/0/loop_wrap = true
 tracks/0/keys = {
 "times": PackedFloat32Array(0),
 "transitions": PackedFloat32Array(1),
-"update": 0,
-"values": [Vector2(0, 982)]
+"update": 1,
+"values": [true]
 }
 tracks/1/type = "value"
 tracks/1/imported = false
 tracks/1/enabled = true
-tracks/1/path = NodePath("SouthWest:visible")
-tracks/1/interp = 1
+tracks/1/path = NodePath("SouthWest:offset_top")
+tracks/1/interp = 2
 tracks/1/loop_wrap = true
 tracks/1/keys = {
 "times": PackedFloat32Array(0),
 "transitions": PackedFloat32Array(1),
-"update": 1,
-"values": [true]
+"update": 0,
+"values": [-98.0]
 }
 
 [sub_resource type="Animation" id="Animation_yis4x"]
@@ -470,27 +470,27 @@ step = 0.02
 tracks/0/type = "value"
 tracks/0/imported = false
 tracks/0/enabled = true
-tracks/0/path = NodePath("SouthWest:position")
-tracks/0/interp = 2
+tracks/0/path = NodePath("SouthWest:visible")
+tracks/0/interp = 1
 tracks/0/loop_wrap = true
 tracks/0/keys = {
-"times": PackedFloat32Array(0, 0.1, 0.4),
-"transitions": PackedFloat32Array(1.618, 1.618, 1),
-"update": 0,
-"values": [Vector2(0, 982), Vector2(0, 960), Vector2(0, 1100)]
-}
-tracks/1/type = "value"
-tracks/1/imported = false
-tracks/1/enabled = true
-tracks/1/path = NodePath("SouthWest:visible")
-tracks/1/interp = 1
-tracks/1/loop_wrap = true
-tracks/1/keys = {
 "times": PackedFloat32Array(0.4),
 "transitions": PackedFloat32Array(1),
 "update": 1,
 "values": [false]
 }
+tracks/1/type = "value"
+tracks/1/imported = false
+tracks/1/enabled = true
+tracks/1/path = NodePath("SouthWest:offset_top")
+tracks/1/interp = 2
+tracks/1/loop_wrap = true
+tracks/1/keys = {
+"times": PackedFloat32Array(0, 0.1, 0.4),
+"transitions": PackedFloat32Array(1.618, 1.618, 1),
+"update": 0,
+"values": [-98.0, -120.0, 20.0]
+}
 
 [sub_resource type="Animation" id="Animation_jugqx"]
 resource_name = "peek"
@@ -499,27 +499,27 @@ step = 0.02
 tracks/0/type = "value"
 tracks/0/imported = false
 tracks/0/enabled = true
-tracks/0/path = NodePath("SouthWest:position")
+tracks/0/path = NodePath("SouthWest:visible")
 tracks/0/interp = 1
 tracks/0/loop_wrap = true
 tracks/0/keys = {
-"times": PackedFloat32Array(0, 0.1, 2.3, 2.4),
-"transitions": PackedFloat32Array(1.618, 1, 1.618, 1),
-"update": 0,
-"values": [Vector2(0, 1100), Vector2(0, 982), Vector2(0, 982), Vector2(0, 1100)]
-}
-tracks/1/type = "value"
-tracks/1/imported = false
-tracks/1/enabled = true
-tracks/1/path = NodePath("SouthWest:visible")
-tracks/1/interp = 1
-tracks/1/loop_wrap = true
-tracks/1/keys = {
 "times": PackedFloat32Array(0, 2.4),
 "transitions": PackedFloat32Array(1, 1),
 "update": 1,
 "values": [true, false]
 }
+tracks/1/type = "value"
+tracks/1/imported = false
+tracks/1/enabled = true
+tracks/1/path = NodePath("SouthWest:offset_top")
+tracks/1/interp = 1
+tracks/1/loop_wrap = true
+tracks/1/keys = {
+"times": PackedFloat32Array(0, 0.1, 2.3, 2.4),
+"transitions": PackedFloat32Array(1.618, 1, 1.618, 1),
+"update": 0,
+"values": [20.0, -98.0, -98.0, 20.0]
+}
 
 [sub_resource type="Animation" id="Animation_nicro"]
 resource_name = "show_life_bar"
@@ -528,27 +528,27 @@ step = 0.02
 tracks/0/type = "value"
 tracks/0/imported = false
 tracks/0/enabled = true
-tracks/0/path = NodePath("SouthWest:position")
-tracks/0/interp = 2
+tracks/0/path = NodePath("SouthWest:visible")
+tracks/0/interp = 1
 tracks/0/loop_wrap = true
 tracks/0/keys = {
-"times": PackedFloat32Array(0, 0.34, 0.4),
-"transitions": PackedFloat32Array(1.618, 1.618, 1),
-"update": 0,
-"values": [Vector2(0, 1100), Vector2(0, 960), Vector2(0, 982)]
-}
-tracks/1/type = "value"
-tracks/1/imported = false
-tracks/1/enabled = true
-tracks/1/path = NodePath("SouthWest:visible")
-tracks/1/interp = 1
-tracks/1/loop_wrap = true
-tracks/1/keys = {
 "times": PackedFloat32Array(0),
 "transitions": PackedFloat32Array(1),
 "update": 1,
 "values": [true]
 }
+tracks/1/type = "value"
+tracks/1/imported = false
+tracks/1/enabled = true
+tracks/1/path = NodePath("SouthWest:offset_top")
+tracks/1/interp = 2
+tracks/1/loop_wrap = true
+tracks/1/keys = {
+"times": PackedFloat32Array(0, 0.34, 0.4),
+"transitions": PackedFloat32Array(1.618, 1.618, 1),
+"update": 0,
+"values": [20.0, -120.0, -98.0]
+}
 
 [sub_resource type="AnimationLibrary" id="AnimationLibrary_c3i4w"]
 _data = {
@@ -782,6 +782,7 @@ anchor_right = 0.333
 anchor_bottom = 1.0
 offset_top = -98.0
 offset_right = 40.0
+offset_bottom = 278.665
 grow_vertical = 0
 theme_override_constants/margin_left = 16
 theme_override_constants/margin_bottom = 16