feat: VFX 인프라 구축 및 Ground Target 시스템 구현

- VfxEffect 스킬 이펙트 클래스 추가 (일회성 VFX 스폰, 위치/스케일/파티클 제어)
- SkillEffect.IsVisualOnly 프로퍼티 추가로 서버 가드 없이 모든 클라이언트에서 VFX 로컬 실행
- SkillProjectile 트레일 VFX 지원 (OnNetworkSpawn에서 양쪽 생성, despawn 시 월드 분리)
- SkillProjectile HitEffectClientRpc 추가로 충돌 이펙트 클라이언트 동기화
- Ground Target 시스템: 타겟팅 모드 상태머신, 인디케이터, 지면 위치 RPC 전달
- 마법 오름 Ground Target 스킬 에셋 및 VfxEffect 에셋 추가
- 마법 오름 애니메이션 클립 추가
- Ground layer (Layer 7) 추가
- ProjectileBasic에 trailPrefab/hitEffect 필드 추가
- Prefabs/VFX/ 폴더 생성

Assets/_Game/Scripts/Skills/Effects/VfxEffect.cs

@@ -0,0 +1,122 @@
+using UnityEngine;
+
+namespace Colosseum.Skills.Effects
+{
+    /// <summary>
+    /// VFX 생성 효과.
+    /// 지정된 위치에 파티클 프리팹을 생성하고, 생명주기 및 재생 옵션을 제어합니다.
+    /// </summary>
+    [CreateAssetMenu(fileName = "VfxEffect", menuName = "Colosseum/Skills/Effects/VFX")]
+    public class VfxEffect : SkillEffect
+    {
+        [Header("VFX 설정")]
+        [Tooltip("생성할 VFX 프리팹")]
+        [SerializeField] private GameObject vfxPrefab;
+
+        [Header("위치 설정")]
+        [Tooltip("VFX 생성 위치: Caster=시전자, CasterForward=시전자 정면, Target=대상 위치, GroundPoint=지면 타겟 위치")]
+        [SerializeField] private VfxSpawnLocation spawnLocation = VfxSpawnLocation.Caster;
+        [Tooltip("위치 오프셋")]
+        [SerializeField] private Vector3 offset = Vector3.zero;
+
+        [Header("생명주기")]
+        [Tooltip("VFX 자동 파괴 시간 (0이면 파괴하지 않음)")]
+        [Min(0f)] [SerializeField] private float lifetime = 2f;
+        [Tooltip("시전자에게 부모 설정 여부")]
+        [SerializeField] private bool parentToCaster = false;
+        [Tooltip("VFX 크기 배율")]
+        [Min(0.01f)] [SerializeField] private float scaleMultiplier = 1f;
+
+        [Header("파티클 설정")]
+        [Tooltip("ParticleSystem 자동 재생 여부 (false면 스폰만 하고 외부에서 제어)")]
+        [SerializeField] private bool autoPlay = true;
+        [Tooltip("ParticleSystem 루핑 여부")]
+        [SerializeField] private bool loop = false;
+
+        /// <summary>
+        /// VFX 효과는 순수 시각 효과이므로 모든 클라이언트에서 로컬 실행됩니다.
+        /// </summary>
+        public override bool IsVisualOnly => true;
+
+        private Vector3? groundPosition;
+
+        /// <summary>
+        /// 지면 타겟 위치를 캡처하여 ApplyEffect에서 사용할 수 있도록 합니다.
+        /// </summary>
+        public override void ExecuteOnCast(GameObject caster, GameObject targetOverride = null, Vector3? groundPosition = null)
+        {
+            this.groundPosition = groundPosition;
+            base.ExecuteOnCast(caster, targetOverride, groundPosition);
+            this.groundPosition = null;
+        }
+
+        /// <summary>
+        /// VFX 프리팹을 생성하고 파티클을 재생합니다.
+        /// </summary>
+        protected override void ApplyEffect(GameObject caster, GameObject target)
+        {
+            if (vfxPrefab == null || caster == null) return;
+
+            try
+            {
+                Vector3 spawnPos = GetSpawnPosition(caster, target);
+                Quaternion spawnRot = caster.transform.rotation;
+                Transform parent = parentToCaster ? caster.transform : null;
+
+                // 비제네릭 Instantiate로 캐스팅 예외 방지
+                GameObject instance = (GameObject)Object.Instantiate(vfxPrefab, spawnPos + offset, spawnRot, parent);
+
+                instance.transform.localScale *= scaleMultiplier;
+
+                if (parentToCaster)
+                    instance.transform.localPosition = offset;
+
+                if (autoPlay)
+                {
+                    ParticleSystem[] particleSystems = instance.GetComponentsInChildren<ParticleSystem>(true);
+                    foreach (var ps in particleSystems)
+                    {
+                        var main = ps.main;
+                        main.loop = loop;
+
+                        if (loop)
+                            main.stopAction = ParticleSystemStopAction.None;
+
+                        ps.Clear(true);
+                        ps.Play(true);
+                    }
+                }
+
+                if (lifetime > 0f)
+                    Object.Destroy(instance, lifetime);
+            }
+            catch (System.Exception e)
+            {
+                Debug.LogError($"[VfxEffect] VFX 생성 실패: {e.Message}\n{e.StackTrace}", this);
+            }
+        }
+
+        /// <summary>
+        /// spawnLocation에 따른 VFX 생성 위치를 계산합니다.
+        /// </summary>
+        private Vector3 GetSpawnPosition(GameObject caster, GameObject target)
+        {
+            return spawnLocation switch
+            {
+                VfxSpawnLocation.Caster => caster.transform.position,
+                VfxSpawnLocation.CasterForward => caster.transform.position + caster.transform.forward * 2f,
+                VfxSpawnLocation.Target => target != null ? target.transform.position : caster.transform.position,
+                VfxSpawnLocation.GroundPoint => groundPosition ?? caster.transform.position,
+                _ => caster.transform.position
+            };
+        }
+    }
+
+    public enum VfxSpawnLocation
+    {
+        Caster,
+        CasterForward,
+        Target,
+        GroundPoint
+    }
+}

Assets/_Game/Scripts/Skills/Effects/VfxEffect.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 69581e050479a094782d2ca9eb142fe4

Assets/_Game/Scripts/Skills/SkillController.cs

@@ -74,6 +74,7 @@ namespace Colosseum.Skills
         private int currentRepeatCount = 1;
         private int currentIterationIndex = 0;
         private GameObject currentTargetOverride;
+        private Vector3? currentGroundTargetPosition;
 
         // 쿨타임 추적
         private Dictionary<SkillData, float> cooldownTracker = new Dictionary<SkillData, float>();
@@ -270,6 +271,17 @@ namespace Colosseum.Skills
             return ExecuteSkillInternal(loadoutEntry);
         }
 
+        /// <summary>
+        /// 지면 타겟 위치와 함께 스킬 시전.
+        /// Ground Target 스킬에서 사용합니다.
+        /// </summary>
+        public bool ExecuteSkill(SkillLoadoutEntry loadoutEntry, GameObject targetOverride, Vector3 groundTargetPosition)
+        {
+            currentTargetOverride = targetOverride;
+            currentGroundTargetPosition = groundTargetPosition;
+            return ExecuteSkillInternal(loadoutEntry);
+        }
+
         /// <summary>
         /// 스킬 시전 공통 로직
         /// </summary>
@@ -328,17 +340,29 @@ namespace Colosseum.Skills
             if (currentSkill == null)
                 return;
 
+            // VFX는 모든 클라이언트에서 로컬 생성 (서버 가드 무시)
+            for (int i = 0; i < currentCastStartEffects.Count; i++)
+            {
+                SkillEffect effect = currentCastStartEffects[i];
+                if (effect != null && effect.IsVisualOnly)
+                {
+                    if (debugMode) Debug.Log($"[Skill] Cast start VFX: {effect.name} (index {i})");
+                    effect.ExecuteOnCast(gameObject, currentTargetOverride, currentGroundTargetPosition);
+                }
+            }
+
+            // 게임플레이 효과는 서버에서만 실행
             if (NetworkManager.Singleton != null && !NetworkManager.Singleton.IsServer)
                 return;
 
             for (int i = 0; i < currentCastStartEffects.Count; i++)
             {
                 SkillEffect effect = currentCastStartEffects[i];
-                if (effect == null)
+                if (effect == null || effect.IsVisualOnly)
                     continue;
 
                 if (debugMode) Debug.Log($"[Skill] Cast start effect: {effect.name} (index {i})");
-                effect.ExecuteOnCast(gameObject, currentTargetOverride);
+                effect.ExecuteOnCast(gameObject, currentTargetOverride, currentGroundTargetPosition);
             }
 
             if (currentCastStartAbnormalities.Count <= 0)
@@ -371,23 +395,35 @@ namespace Colosseum.Skills
             if (currentSkill == null || currentTriggeredEffects.Count == 0)
                 return;
 
-            if (NetworkManager.Singleton != null && !NetworkManager.Singleton.IsServer)
-                return;
-
             if (currentSkill.SkillClip != null && currentSkill.SkillClip.events != null && currentSkill.SkillClip.events.Length > 0)
                 return;
 
             if (!currentTriggeredEffects.TryGetValue(0, out List<SkillEffect> effectsAtZero))
                 return;
 
+            // VFX는 모든 클라이언트에서 로컬 생성 (서버 가드 무시)
             for (int i = 0; i < effectsAtZero.Count; i++)
             {
                 SkillEffect effect = effectsAtZero[i];
-                if (effect == null || effect.TargetType != TargetType.Self)
+                if (effect != null && effect.IsVisualOnly && effect.TargetType == TargetType.Self)
+                {
+                    if (debugMode) Debug.Log($"[Skill] Immediate self VFX: {effect.name} (index {i})");
+                    effect.ExecuteOnCast(gameObject, currentTargetOverride, currentGroundTargetPosition);
+                }
+            }
+
+            // 게임플레이 효과는 서버에서만 실행
+            if (NetworkManager.Singleton != null && !NetworkManager.Singleton.IsServer)
+                return;
+
+            for (int i = 0; i < effectsAtZero.Count; i++)
+            {
+                SkillEffect effect = effectsAtZero[i];
+                if (effect == null || effect.TargetType != TargetType.Self || effect.IsVisualOnly)
                     continue;
 
                 if (debugMode) Debug.Log($"[Skill] Immediate self effect: {effect.name} (index {i})");
-                effect.ExecuteOnCast(gameObject, currentTargetOverride);
+                effect.ExecuteOnCast(gameObject, currentTargetOverride, currentGroundTargetPosition);
             }
         }
 
@@ -561,8 +597,6 @@ namespace Colosseum.Skills
         /// </summary>
         public void OnEffect(int index)
         {
-            if (NetworkManager.Singleton != null && !NetworkManager.Singleton.IsServer) return;
-
             if (currentSkill == null)
             {
                 if (debugMode) Debug.LogWarning("[Effect] No skill executing");
@@ -583,10 +617,24 @@ namespace Colosseum.Skills
                 return;
             }
 
+            // VFX는 모든 클라이언트에서 로컬 생성 (서버 가드 무시)
             for (int i = 0; i < effects.Count; i++)
             {
                 SkillEffect effect = effects[i];
-                if (effect == null)
+                if (effect != null && effect.IsVisualOnly)
+                {
+                    if (debugMode) Debug.Log($"[Effect] VFX: {effect.name} (index {index})");
+                    effect.ExecuteOnCast(gameObject, currentTargetOverride, currentGroundTargetPosition);
+                }
+            }
+
+            // 게임플레이 효과는 서버에서만 실행
+            if (NetworkManager.Singleton != null && !NetworkManager.Singleton.IsServer) return;
+
+            for (int i = 0; i < effects.Count; i++)
+            {
+                SkillEffect effect = effects[i];
+                if (effect == null || effect.IsVisualOnly)
                     continue;
 
                 if (debugMode) Debug.Log($"[Effect] {effect.name} (index {index})");
@@ -594,13 +642,11 @@ namespace Colosseum.Skills
                 // 공격 범위 시각화
                 if (showAreaDebug)
                 {
-                    effect.DrawDebugRange(gameObject, debugDrawDuration);
+                    effect.DrawDebugRange(gameObject, debugDrawDuration, currentGroundTargetPosition);
                 }
 
-                effect.ExecuteOnCast(gameObject, currentTargetOverride);
+                effect.ExecuteOnCast(gameObject, currentTargetOverride, currentGroundTargetPosition);
             }
-
-            ApplyTriggeredAbnormalities(index, effects);
         }
 
         /// <summary>
@@ -684,6 +730,7 @@ namespace Colosseum.Skills
             currentTriggeredAbnormalities.Clear();
             currentTriggeredTargetsBuffer.Clear();
             currentTargetOverride = null;
+            currentGroundTargetPosition = null;
             currentClipSequenceIndex = 0;
             currentRepeatCount = 1;
             currentIterationIndex = 0;
@@ -709,7 +756,7 @@ namespace Colosseum.Skills
                 if (effect == null || effect.TargetType == TargetType.Self)
                     continue;
 
-                effect.CollectTargets(gameObject, currentTriggeredTargetsBuffer, currentTargetOverride);
+                effect.CollectTargets(gameObject, currentTriggeredTargetsBuffer, currentTargetOverride, currentGroundTargetPosition);
             }
 
             if (currentTriggeredTargetsBuffer.Count == 0)

Assets/_Game/Scripts/Skills/SkillEffect.cs

@@ -45,14 +45,21 @@ namespace Colosseum.Skills
         public float FanRadius => fanRadius;
         public float FanHalfAngle => fanHalfAngle;
         public bool IncludeCasterInArea => includeCasterInArea;
+        public AreaCenterType AreaCenter => areaCenter;
+
+        /// <summary>
+        /// 이 효과가 순수 시각 효과인지 확인합니다.
+        /// true이면 서버 가드를 무시하고 모든 클라이언트에서 로컬 실행됩니다.
+        /// </summary>
+        public virtual bool IsVisualOnly => false;
 
         /// <summary>
         /// 스킬 시전 시 호출
         /// </summary>
-        public void ExecuteOnCast(GameObject caster, GameObject targetOverride = null)
+        public virtual void ExecuteOnCast(GameObject caster, GameObject targetOverride = null, Vector3? groundPosition = null)
         {
             List<GameObject> targets = new List<GameObject>();
-            CollectTargets(caster, targets, targetOverride);
+            CollectTargets(caster, targets, targetOverride, groundPosition);
 
             for (int i = 0; i < targets.Count; i++)
             {
@@ -64,7 +71,7 @@ namespace Colosseum.Skills
         /// 현재 효과가 영향을 줄 대상 목록을 수집합니다.
         /// 젬의 적중 이상상태 적용 등에서 동일한 타겟 해석을 재사용하기 위한 경로입니다.
         /// </summary>
-        public void CollectTargets(GameObject caster, List<GameObject> destination, GameObject targetOverride = null)
+        public void CollectTargets(GameObject caster, List<GameObject> destination, GameObject targetOverride = null, Vector3? groundPosition = null)
         {
             if (caster == null || destination == null)
                 return;
@@ -76,7 +83,7 @@ namespace Colosseum.Skills
                     break;
 
                 case TargetType.Area:
-                    CollectAreaTargets(caster, destination);
+                    CollectAreaTargets(caster, destination, groundPosition);
                     break;
 
                 case TargetType.SingleAlly:
@@ -135,9 +142,9 @@ namespace Colosseum.Skills
             };
         }
 
-        private void CollectAreaTargets(GameObject caster, List<GameObject> destination)
+        private void CollectAreaTargets(GameObject caster, List<GameObject> destination, Vector3? groundPosition = null)
         {
-            Vector3 center = GetAreaCenter(caster);
+            Vector3 center = GetAreaCenter(caster, groundPosition);
             Collider[] hits = Physics.OverlapSphere(center, Mathf.Max(areaRadius, fanRadius), targetLayers);
             foreach (var hit in hits)
             {
@@ -189,7 +196,7 @@ namespace Colosseum.Skills
             return angle <= fanHalfAngle;
         }
 
-        private Vector3 GetAreaCenter(GameObject caster)
+        private Vector3 GetAreaCenter(GameObject caster, Vector3? groundPosition = null)
         {
             if (caster == null) return Vector3.zero;
 
@@ -197,6 +204,7 @@ namespace Colosseum.Skills
             {
                 AreaCenterType.Caster => caster.transform.position,
                 AreaCenterType.CasterForward => caster.transform.position + caster.transform.forward * areaRadius,
+                AreaCenterType.GroundPoint => groundPosition ?? caster.transform.position,
                 _ => caster.transform.position
             };
         }
@@ -205,7 +213,7 @@ namespace Colosseum.Skills
         /// <summary>
         /// 공격 범위 시각화 (런타임 디버그용)
         /// </summary>
-        public void DrawDebugRange(GameObject caster, float duration = 1f)
+        public void DrawDebugRange(GameObject caster, float duration = 1f, Vector3? groundPosition = null)
         {
             if (targetType != TargetType.Area) return;
 
@@ -214,12 +222,15 @@ namespace Colosseum.Skills
 
             if (areaShape == AreaShapeType.Sphere)
             {
-                Vector3 center = GetAreaCenter(caster);
+                Vector3 center = GetAreaCenter(caster, groundPosition);
                 DebugDrawSphere(center, areaRadius, Color.red, duration);
             }
             else if (areaShape == AreaShapeType.Fan)
             {
-                DebugDrawFan(casterPos, forward, fanOriginDistance, fanRadius, fanHalfAngle, Color.red, duration);
+                Vector3 center = GetAreaCenter(caster, groundPosition);
+                DebugDrawFan(center, groundPosition.HasValue && areaCenter == AreaCenterType.GroundPoint
+                    ? (center - casterPos).normalized
+                    : forward, fanOriginDistance, fanRadius, fanHalfAngle, Color.red, duration);
             }
         }
 
@@ -296,7 +307,8 @@ namespace Colosseum.Skills
     public enum AreaCenterType
     {
         Caster,
-        CasterForward
+        CasterForward,
+        GroundPoint  // 지면 지점 타겟팅 (Ground Target)
     }
 
     public enum AreaShapeType

Assets/_Game/Scripts/Skills/SkillProjectile.cs

@@ -22,11 +22,18 @@ namespace Colosseum.Skills
         [SerializeField] private GameObject hitEffect;
         [SerializeField] private float hitEffectDuration = 2f;
 
+        [Header("트레일 이펙트")]
+        [Tooltip("투사체 트레일 프리팹 (TrailRenderer가 포함된 프리팹). 미설정 시 트레일 없음.")]
+        [SerializeField] private GameObject trailPrefab;
+        [Tooltip("투사체 파괴 후 트레일이 남는 시간 (초)")]
+        [Min(0.1f)] [SerializeField] private float trailDuration = 0.3f;
+
         private GameObject caster;
         private SkillEffect sourceEffect;
         private int penetrationCount;
         private Rigidbody rb;
         private bool initialized;
+        private GameObject trailInstance;
 
         /// <summary>
         /// 투사체 초기화
@@ -51,6 +58,17 @@ namespace Colosseum.Skills
                     Physics.IgnoreCollision(mc, cc);
         }
 
+        public override void OnNetworkSpawn()
+        {
+            // 트레일 생성 (서버/클라이언트 양쪽에서 실행)
+            if (trailPrefab != null)
+            {
+                trailInstance = Instantiate(trailPrefab, transform);
+                trailInstance.transform.localPosition = Vector3.zero;
+                trailInstance.transform.localRotation = Quaternion.identity;
+            }
+        }
+
         private void Start()
         {
             // 서버에서만 수명 관리
@@ -75,11 +93,12 @@ namespace Colosseum.Skills
             if (!sourceEffect.IsValidTarget(caster, other.gameObject))
                 return;
 
-            // 충돌 이펙트 (서버에서 스폰 → 클라이언트에도 표시되려면 NetworkObject여야 함)
+            // 충돌 이펙트 (서버 + 클라이언트 모두 표시)
             if (hitEffect != null)
             {
                 var effect = Instantiate(hitEffect, transform.position, transform.rotation);
                 Destroy(effect, hitEffectDuration);
+                HitEffectClientRpc(transform.position, transform.rotation.eulerAngles);
             }
 
             // 효과 적용
@@ -96,6 +115,15 @@ namespace Colosseum.Skills
         private void ServerDespawn()
         {
             if (!IsServer || !IsSpawned) return;
+
+            // 트레일을 월드에 남겨서 자연스럽게 사라지게 함
+            if (trailInstance != null)
+            {
+                trailInstance.transform.SetParent(null);
+                Destroy(trailInstance, trailDuration);
+                trailInstance = null;
+            }
+
             NetworkObject.Despawn(true);
         }
 
@@ -103,5 +131,18 @@ namespace Colosseum.Skills
         {
             transform.rotation = Quaternion.LookRotation(direction.normalized);
         }
+
+        /// <summary>
+        /// 클라이언트에 충돌 이펙트 표시
+        /// </summary>
+        [Rpc(SendTo.NotServer)]
+        private void HitEffectClientRpc(Vector3 position, Vector3 eulerAngles)
+        {
+            if (hitEffect != null)
+            {
+                var effect = Instantiate(hitEffect, position, Quaternion.Euler(eulerAngles));
+                Destroy(effect, hitEffectDuration);
+            }
+        }
     }
 }