2nd/10_Wiki/Topic_Programming/Architecture/가상현실(VR).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-vr	가상현실(VR)	10_Wiki/Topics	verified	self	VR Virtual Reality 가상현실	none	A	0.9	applied	vr xr immersive hardware graphics		2026-05-10	pending	language framework C++ OpenXR / Unity XR / Unreal XR

가상현실(VR)

매 한 줄

"매 VR 의 head-mounted display + 6DoF tracking 의 immersive 3D world.". 매 1968 Sutherland 의 Sword of Damocles 의 origin, 매 2026 의 Apple Vision Pro 2 / Quest 4 / Valve Deckard 의 mainstream 진입, 매 spatial computing 의 paradigm shift.

매 핵심

매 hardware stack

• HMD: dual-display (매 eye 마다 4K micro-OLED 의 2026 표준).
• Tracking: inside-out SLAM (매 cameras + IMU) 또는 outside-in lighthouse.
• Controllers: 6DoF + finger tracking + haptics.
• Eye tracking + foveated rendering: 매 GPU cost 의 50-70% 감소.

매 software stack

• OpenXR: 매 Khronos cross-vendor standard.
• Unity XR / Unreal XR / Godot XR: engine layer.
• WebXR: browser-based VR.
• visionOS / Horizon OS / SteamVR: platform layer.

매 응용

1. Gaming (Half-Life Alyx, Beat Saber).
2. Training simulation (surgery, aviation, military).
3. Virtual collaboration (Horizon Workrooms, Spatial).
4. Therapy (PTSD exposure, phobia treatment).

💻 패턴

Pattern 1 — OpenXR session bootstrap (C++)

XrInstance instance;
XrInstanceCreateInfo ci{XR_TYPE_INSTANCE_CREATE_INFO};
strcpy(ci.applicationInfo.applicationName, "MyVRApp");
ci.applicationInfo.apiVersion = XR_CURRENT_API_VERSION;
xrCreateInstance(&ci, &instance);

XrSystemId sysId;
XrSystemGetInfo sgi{XR_TYPE_SYSTEM_GET_INFO};
sgi.formFactor = XR_FORM_FACTOR_HEAD_MOUNTED_DISPLAY;
xrGetSystem(instance, &sgi, &sysId);

Pattern 2 — Unity XR Interaction (C#)

using UnityEngine.XR.Interaction.Toolkit;

public class GrabHandler : MonoBehaviour {
    void OnEnable() {
        var grab = GetComponent<XRGrabInteractable>();
        grab.selectEntered.AddListener(OnGrab);
    }
    void OnGrab(SelectEnterEventArgs args) {
        Debug.Log($"Grabbed by {args.interactorObject}");
    }
}

Pattern 3 — foveated rendering hint (Unreal)

// VRS (Variable Rate Shading) tied to eye gaze
FEyeTrackerGazeData gaze;
UEyeTrackerFunctionLibrary::GetGazeData(gaze);
FoveationRenderer->SetFoveationCenter(gaze.GazeOrigin, gaze.GazeDirection);
FoveationRenderer->SetFoveationLevel(EFoveationLevel::High);

Pattern 4 — locomotion (teleport, smooth, room-scale)

// Teleport: discrete jump (low motion sickness).
// Smooth: continuous joystick (immersion ↑, sickness ↑).
// Room-scale: physical walking within play area.
locomotionProvider.MoveType = comfortSetting == HIGH ? Teleport : Smooth;

Pattern 5 — async reprojection (90Hz lock)

// Compositor re-warps last frame using latest head pose
// when app misses frame budget. Critical for sub-20ms motion-to-photon.
xrEndFrame(session, &endInfo); // compositor handles reprojection

Pattern 6 — WebXR session

const session = await navigator.xr.requestSession('immersive-vr', {
  requiredFeatures: ['local-floor', 'hand-tracking']
});
const refSpace = await session.requestReferenceSpace('local-floor');
session.requestAnimationFrame(onXRFrame);

매 결정 기준

상황	Approach
매 cross-platform deploy	OpenXR + Unity XR
매 web reach	WebXR
매 Apple ecosystem only	visionOS native (Swift + RealityKit)
매 maximum fidelity (PCVR)	Unreal + Vulkan
매 mobile standalone	Quest native (Android NDK)

기본값: 매 Unity XR + OpenXR 의 cross-vendor.

🔗 Graph

• 부모: Computer-Graphics · Human Computer Interaction
• 변형: Mixed-Reality · Spatial Computing
• Adjacent: 깊이_지각(Depth_perception)

🤖 LLM 활용

언제: 매 immersive simulation 의 design 시, 매 OpenXR API 의 boilerplate 생성, 매 locomotion 의 comfort tradeoff 분석. 언제 X: 매 hardware-specific tuning (매 HMD 마다 의 IPD calibration), 매 user 의 actual motion sickness 의 real-world test.

❌ 안티패턴

• Frame drops: 매 90Hz 미달 → motion sickness 직결. 매 budget 의 11ms hard cap.
• Smooth locomotion default: 매 first-time user 의 nausea 의 cause. Teleport default.
• Camera jerks: 매 cinematic cuts 의 cinema convention 의 VR 적용 금지.
• Tiny UI: 매 angular size <2° 의 unreadable. 매 dpi 의 web 의 mental model 금지.

🧪 검증 / 중복

• Verified (Khronos OpenXR spec, Apple visionOS docs, Meta Developer docs).
• 신뢰도 A.

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — VR hardware/software stack + OpenXR/Unity/Unreal patterns