feat(vfx): animate movement and scoring effects

Game/scripts/goal.gd

@@ -26,6 +26,8 @@ const RIM_DEPTH := 0.05
 
 const NET_SHADER_PATH := "res://shaders/goal_net.gdshader"
 
+var _goal_burst: GPUParticles3D
+
 
 func _ready():
 	# Group lets AI controllers and game modes discover goals
@@ -34,10 +36,13 @@ func _ready():
 	# headless arenas that never render it. The sensor is unaffected.
 	if DisplayServer.get_name() != "headless":
 		_build_visuals()
+		_build_goal_burst()
 
 
 func _on_body_entered(body):
 	if body.is_in_group("ball"):
+		if _goal_burst:
+			_goal_burst.restart()
 		goal_scored.emit(team)
 
 
@@ -103,6 +108,43 @@ func _build_visuals() -> void:
 	add_child(visuals)
 
 
+func _build_goal_burst() -> void:
+	var tint: Color = TeamColors.TEAM_COLORS[team % TeamColors.TEAM_COLORS.size()]
+	var mat := StandardMaterial3D.new()
+	mat.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
+	mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
+	mat.billboard_mode = BaseMaterial3D.BILLBOARD_ENABLED
+	mat.albedo_color = Color(tint.r, tint.g, tint.b, 0.9)
+	mat.emission_enabled = true
+	mat.emission = tint
+	mat.emission_energy_multiplier = 3.0
+	var quad := QuadMesh.new()
+	quad.size = Vector2(0.38, 0.8)
+	quad.material = mat
+	var process := ParticleProcessMaterial.new()
+	process.emission_shape = ParticleProcessMaterial.EMISSION_SHAPE_BOX
+	process.emission_box_extents = Vector3(1.7, 0.7, 0.15)
+	process.direction = Vector3(0, 0, -1)
+	process.spread = 48.0
+	process.initial_velocity_min = 8.0
+	process.initial_velocity_max = 18.0
+	process.gravity = Vector3(0, -2.0, 0)
+	process.scale_min = 0.35
+	process.scale_max = 1.2
+	_goal_burst = GPUParticles3D.new()
+	_goal_burst.name = "GoalBurst"
+	_goal_burst.position = Vector3(0, 0, -0.15)
+	_goal_burst.amount = 140
+	_goal_burst.lifetime = 1.1
+	_goal_burst.one_shot = true
+	_goal_burst.explosiveness = 0.92
+	_goal_burst.process_material = process
+	_goal_burst.draw_pass_1 = quad
+	_goal_burst.visibility_aabb = AABB(Vector3(-12, -8, -20), Vector3(24, 16, 24))
+	_goal_burst.emitting = false
+	add_child(_goal_burst)
+
+
 # Four bars around the mouth. The uprights run the full outer height so each
 # corner is covered exactly once.
 func _add_frame_ring(