2nd/10_Wiki/Topic_Programming/Programming & Language/가상현실 멀미 (VR Sickness).md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-가상현실-멀미-vr-sickness	가상현실 멀미 (VR Sickness)	10_Wiki/Topics	verified	self	VR Sickness Cybersickness Motion Sickness in VR	none	A	0.9	applied	vr ux perception motion-sickness hmd		2026-05-10	pending	language framework C# Unity/Unreal

가상현실 멀미 (VR Sickness)

매 한 줄

"매 vestibular (전정) 와 visual (시각) input 의 mismatch 로 발생하는 nausea / disorientation". 매 motion sickness 의 inverse — 매 눈은 움직임을 보지만 몸은 정지. 매 90+ FPS, low-latency tracking, comfort locomotion 으로 완화. 매 Quest 3 / Vision Pro 시대에도 여전히 핵심 UX 문제.

매 핵심

매 원인 (sensory conflict theory)

• Vection: 매 visual self-motion 의 인지 (정지한 vestibular 와 conflict).
• Latency: motion-to-photon >20ms — 매 멀미 유발.
• Frame rate dip: 90Hz → 60Hz drop 의 즉시 swimming sensation.
• Field of view + speed: 매 wide FOV + fast translation = 매 worst.
• Postural instability: 매 head tracking error / drift.

매 완화 기법

• High refresh rate: 90/120Hz 표준 (Quest 3 = 120Hz, Vision Pro = 90/96Hz).
• Low motion-to-photon latency: <20ms target.
• Vignette / Tunneling: 매 turn / locomotion 시 peripheral 차단.
• Teleport locomotion: 매 smooth movement 의 회피.
• Snap turning: 30/45° discrete rotation.
• Stable horizon / cockpit: 매 reference frame 의 제공.
• Comfort rating: Comfortable / Moderate / Intense — 매 store labeling.

매 응용

1. VR game design (Half-Life: Alyx, Beat Saber).
2. Training sim (medical, military, flight).
3. VR therapy 의 조정 (exposure therapy, PTSD).
4. Industrial design review.

💻 패턴

Unity 의 vignette on locomotion (URP)

using UnityEngine;
using UnityEngine.Rendering.Universal;

public class ComfortVignette : MonoBehaviour {
    [SerializeField] Volume volume;
    Vignette vignette;
    public CharacterController player;

    void Start() { volume.profile.TryGet(out vignette); }
    void Update() {
        float speed = player.velocity.magnitude;
        // 매 빠를수록 매 강한 vignette
        vignette.intensity.value = Mathf.Clamp01(speed / 5f) * 0.6f;
    }
}

Snap Turn 구현

public class SnapTurn : MonoBehaviour {
    public float snapAngle = 30f;
    public Transform xrRig;
    bool turning;

    void Update() {
        float x = Input.GetAxis("RightStickX");
        if (Mathf.Abs(x) > 0.7f && !turning) {
            xrRig.Rotate(0, Mathf.Sign(x) * snapAngle, 0);
            turning = true;
        }
        if (Mathf.Abs(x) < 0.3f) turning = false;
    }
}

Teleport locomotion (XR Interaction Toolkit)

// XR Interaction Toolkit 의 TeleportationProvider + TeleportationArea 사용.
// 매 thumbstick forward → arc raycast → release → fade-to-black → reposition.
public class TeleportFade : MonoBehaviour {
    public ScreenFader fader;
    public IEnumerator FadeTeleport(System.Action moveAction) {
        yield return fader.FadeOut(0.15f);
        moveAction();
        yield return fader.FadeIn(0.15f);
    }
}

Frame rate budget guard (Unity profiler)

void Update() {
    float dt = Time.unscaledDeltaTime;
    if (dt > 1f / 80f) {  // 12.5ms — 90Hz budget 위반
        Debug.LogWarning($"Frame {dt*1000:F1}ms — VR comfort risk");
    }
}

Stable cockpit reference (vehicle VR)

// 매 driver 시점 — 매 cockpit 매 항상 보이도록.
// 매 strong reference frame 으로 vection 감소.
public class CockpitAnchor : MonoBehaviour {
    public Transform vehicle;
    void LateUpdate() {
        transform.position = vehicle.position;
        transform.rotation = vehicle.rotation;
    }
}

Async time warp / reprojection (built-in to Quest, Vision Pro)

// 매 platform 자동 — frame miss 시 last frame 의 reproject.
// 매 dev 작업: 매 frame budget 안정 유지로 reproject 발동 X 가 best.

매 결정 기준

상황	Approach
매 first-person locomotion	teleport + comfort vignette
매 cockpit (car, plane)	smooth motion OK + stable reference frame
매 turning	snap turn (default), smooth turn (option)
매 wide FOV + fast	vignette + reduced FOV
매 cinematic camera	매 user-controlled — automated camera 의 X

기본값: 매 90Hz+, teleport locomotion, snap turn 30°, comfort vignette, motion-to-photon <20ms.

🔗 Graph

• 부모: Virtual Reality
• 변형: Cybersickness · Simulator Sickness

🤖 LLM 활용

언제: VR UX review, comfort rating 추정, locomotion design feedback. 언제 X: 매 individual susceptibility 진단 — 매 user testing 필수.

❌ 안티패턴

• Cinematic forced camera: 매 user 통제 X — 즉시 멀미.
• 60Hz VR: 매 사실상 unusable.
• Floating UI head-locked: 매 head movement 따라 밀착 → vection.
• Acceleration-heavy locomotion: jerk 의 직접 유발.
• No comfort rating disclosure: 매 store policy 위반 (Quest, Steam).

🧪 검증 / 중복

• Verified (LaViola 3D User Interfaces 2nd ed. 2017, Meta VR Design Guidelines 2024, Apple visionOS HIG).
• 신뢰도 A.

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — sensory conflict + comfort techniques + Unity patterns