2nd/10_Wiki/Topic_Programming/Architecture/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-vr-sickness	VR Sickness	10_Wiki/Topics	verified	self	Cybersickness VR Motion Sickness Simulator Sickness	none	A	0.9	applied	vr ux perception comfort		2026-05-10	pending	language framework csharp unity-xr

VR Sickness

매 한 줄

"매 vestibular system 매 시각-전정 mismatch 매 만들면 매 nausea 의 발생". 매 1990s simulator sickness 연구의 매 VR 확장 — 매 2026 매 Quest 3, Vision Pro, Pico 4 Ultra 매 90Hz+ / foveated rendering 으로 매 줄어들고 있지만 매 design choice (locomotion, FOV) 가 매 dominant factor.

매 핵심

매 원인 (Sensory Conflict Theory)

• Visual-vestibular mismatch: 눈은 movement 보지만 inner ear 는 stationary 신호 — 매 brain 의 "독 상태" 추정.
• Latency: motion-to-photon > 20ms 매 sickness 급증.
• Low frame rate: < 90Hz, 특히 dropped frame, 매 trigger.
• FOV manipulation: peripheral vision movement 매 강한 vection.
• IPD mismatch: 매 잘못된 inter-pupillary distance 매 eye strain → nausea.
• Acceleration in virtual locomotion: 매 constant velocity OK, 매 acceleration 의 매 worst.

매 완화 기법

• Teleport locomotion: 매 smooth move 보다 매 sickness ~80% 감소.
• Tunneling / vignette: peripheral 의 dark mask, vection 줄임.
• Snap turn: smooth turn 대신 30~45° 매 step rotation.
• Static reference frame: cockpit, helmet rim 등 매 fixed visual anchor.
• High refresh + reprojection: 90Hz 이상 + ATW/ASW.
• Foveated rendering: 매 GPU budget 매 free up → frame stability.

매 응용

1. Beat Saber: stationary play, 매 sickness rare.
2. Half-Life Alyx: teleport + smooth 양쪽 옵션, comfort slider.
3. Microsoft Flight Sim VR: cockpit anchor, 매 long-session OK.
4. No Man's Sky VR: smooth locomotion default — 매 highest sickness reports.

💻 패턴

Comfort vignette (Unity URP)

// 매 movement speed 매 따라 매 peripheral mask 매 강도 조절
using UnityEngine;
using UnityEngine.Rendering.Universal;

public class ComfortVignette : MonoBehaviour {
    [SerializeField] Vignette vignette;
    [SerializeField] CharacterController player;
    [SerializeField] float maxIntensity = 0.6f;

    void Update() {
        float speed = player.velocity.magnitude;
        float t = Mathf.Clamp01(speed / 4f); // 4 m/s 매 full vignette
        vignette.intensity.value = t * maxIntensity;
    }
}

Snap turn input

public class SnapTurn : MonoBehaviour {
    [SerializeField] Transform xrRig;
    [SerializeField] float snapDegrees = 30f;
    [SerializeField] float deadzone = 0.7f;
    bool armed = true;

    void Update() {
        float x = OVRInput.Get(OVRInput.Axis2D.SecondaryThumbstick).x;
        if (Mathf.Abs(x) < deadzone) { armed = true; return; }
        if (!armed) return;
        xrRig.Rotate(0, Mathf.Sign(x) * snapDegrees, 0);
        armed = false;
    }
}

Teleport locomotion (XR Interaction Toolkit)

// 매 XRI 의 매 TeleportationProvider + arc raycaster 사용
using UnityEngine;
using UnityEngine.XR.Interaction.Toolkit.Locomotion.Teleportation;

public class TeleportTrigger : MonoBehaviour {
    [SerializeField] TeleportationProvider provider;
    public void RequestTeleport(Vector3 destination) {
        var req = new TeleportRequest {
            destinationPosition = destination,
            matchOrientation = MatchOrientation.WorldSpaceUp,
        };
        provider.QueueTeleportRequest(req);
    }
}

Frame timing budget check

// 매 frame budget 위반 매 detect — Quest 3 매 11.1ms@90Hz, 8.3ms@120Hz
void LateUpdate() {
    float budget = 1f / Application.targetFrameRate;
    if (Time.unscaledDeltaTime > budget * 1.2f) {
        Debug.LogWarning($"Frame overran: {Time.unscaledDeltaTime*1000f:F1}ms");
    }
}

IPD calibration

// OpenXR 매 user IPD 매 read — 매 잘못 설정 매 nausea 의 hidden cause
using UnityEngine.XR;

float GetIpdMeters() {
    var head = InputDevices.GetDeviceAtXRNode(XRNode.Head);
    head.TryGetFeatureValue(CommonUsages.eyesData, out var eyes);
    var l = eyes.leftEye.position;
    var r = eyes.rightEye.position;
    return Vector3.Distance(l, r);
}

Dynamic foveated rendering toggle (Quest 3)

// Quest 3 매 eye-tracked foveation — frame stability 의 강력한 도구
OVRManager.eyeTrackedFoveatedRenderingEnabled = true;
OVRManager.foveatedRenderingLevel = OVRManager.FoveatedRenderingLevel.HighTop;

매 결정 기준

상황	Approach
Casual / first-time user	Teleport + snap turn default
Action / FPS	Smooth + vignette + snap turn option
Sim (flight, racing)	Cockpit anchor, smooth, 90Hz+ guaranteed
Standing-only experience	거의 sickness-free — Beat Saber model
Seated narrative	Static camera + cuts, no virtual locomotion

기본값: Comfort menu 의 매 모든 option 매 expose — user 가 choose.

🔗 Graph

• 변형: Cybersickness · Simulator Sickness

🤖 LLM 활용

언제: VR comfort design review, locomotion option 추천, frame budget 분석. 언제 X: AR / pass-through 만 (vestibular conflict 적음), non-immersive VR / 360 video.

❌ 안티패턴

• Forced smooth locomotion: comfort option 의 X — 매 user churn.
• Cinematic camera shake: VR 매 절대 X — 매 immediate nausea.
• Acceleration / deceleration smooth curve: linear 보다 매 더 sick.
• Stuttering / dropped frames: 60Hz 의 매 X — 매 90Hz minimum.
• High-altitude vertigo without snap: 매 some users 매 panic + sickness.
• No comfort settings menu: 2026 매 standard expectation.

🧪 검증 / 중복

• Verified (Oculus Best Practices 2025, Apple Vision Pro HIG, IEEE VR 2025 cybersickness papers).
• 신뢰도 A.

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — sensory conflict theory, mitigation patterns, Unity XR code