2nd/10_Wiki/Topics/Architecture/Stat-Injection-and-Visual-Renderer-Pipeline.md

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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-stat-injection-and-visual-render	Stat Injection and Visual Renderer Pipeline	10_Wiki/Topics	verified	self	Stat Injection Pipeline Visual Renderer Pipeline	none	B	0.8	applied	game-engine ecs rendering-pipeline data-flow		2026-05-10	pending	language framework rust bevy

Stat Injection and Visual Renderer Pipeline

매 한 줄

"매 simulation stats (HP, mana, status) → 매 visual layer (sprites, VFX, UI) 의 one-way injection pipeline". 매 game engine 의 ECS pattern + 매 render system. 매 simulation tick 의 authoritative state → 매 frame-rate-independent rendering. 2026 매 Bevy ECS, Unity DOTS, Unreal MASS 가 매 reference.

매 핵심

매 데이터 흐름

1. Simulation tick (fixed 60 Hz): 매 stats mutation (Damage, Heal, StatusEffect).
2. Stat aggregation: 매 base + buffs + equipment modifiers.
3. Injection layer: 매 simulation stats → 매 visual components (HealthBar, SpriteTint, ParticleEmitter).
4. Render pipeline: 매 cull → batch → draw call → GPU.
5. Frame interpolation: 매 sim tick rate 와 매 render rate 의 mismatch 의 smooth.

매 layers

• Authoritative: simulation Components (Health, Mana, Position).
• Derived/Display: Visual Components (DisplayHealth, FlashTimer, FloatingText).
• Renderer: Sprite, Mesh, Material, Shader.
• Pipeline stages: Update → Late Update → PostUpdate → Render.

매 응용

1. RPG combat — damage number 의 popup, sprite flash on hit.
2. RTS — health bar, status icon, fog-of-war overlay.
3. Action game — hit-stop, screen shake, VFX 의 trigger.

💻 패턴

Bevy ECS (Rust 1.83) — stat → visual injection

use bevy::prelude::*;

#[derive(Component)] struct Health { current: f32, max: f32 }
#[derive(Component)] struct HealthBar; // visual marker
#[derive(Component)] struct DamageFlash { timer: Timer }

fn inject_health_to_bar(
    actors: Query<&Health, Changed<Health>>,
    mut bars: Query<(&Parent, &mut Sprite), With<HealthBar>>,
) {
    for (parent, mut sprite) in bars.iter_mut() {
        if let Ok(h) = actors.get(parent.get()) {
            let ratio = h.current / h.max;
            sprite.custom_size = Some(Vec2::new(64.0 * ratio, 6.0));
            sprite.color = Color::rgb(1.0 - ratio, ratio, 0.0);
        }
    }
}

Damage event → flash injection

#[derive(Event)] struct DamageEvent { target: Entity, amount: f32 }

fn on_damage(
    mut events: EventReader<DamageEvent>,
    mut commands: Commands,
    mut healths: Query<&mut Health>,
) {
    for ev in events.read() {
        if let Ok(mut h) = healths.get_mut(ev.target) {
            h.current -= ev.amount;
            commands.entity(ev.target).insert(DamageFlash {
                timer: Timer::from_seconds(0.15, TimerMode::Once),
            });
        }
    }
}

fn tick_flash(
    time: Res<Time>,
    mut q: Query<(Entity, &mut DamageFlash, &mut Sprite)>,
    mut commands: Commands,
) {
    for (e, mut f, mut s) in q.iter_mut() {
        f.timer.tick(time.delta());
        s.color = if f.timer.finished() { Color::WHITE } else { Color::RED };
        if f.timer.finished() { commands.entity(e).remove::<DamageFlash>(); }
    }
}

Frame interpolation (fixed sim, variable render)

#[derive(Component)] struct Transform2D { pos: Vec2 }
#[derive(Component)] struct PrevPos(Vec2);

fn interpolate_render(
    fixed: Res<FixedTime>,
    q: Query<(&Transform2D, &PrevPos, &mut Transform)>,
) {
    let alpha = fixed.accumulated().as_secs_f32() / fixed.timestep().as_secs_f32();
    for (cur, prev, mut t) in q.iter_mut() {
        let p = prev.0.lerp(cur.pos, alpha);
        t.translation = p.extend(t.translation.z);
    }
}

Render pipeline stages (Bevy schedule)

app.add_systems(FixedUpdate, (apply_damage, regen_mana))
   .add_systems(Update, (inject_health_to_bar, tick_flash))
   .add_systems(PostUpdate, (cull_offscreen, batch_sprites));

Floating damage text

fn spawn_damage_text(mut commands: Commands, mut events: EventReader<DamageEvent>,
                     transforms: Query<&Transform>) {
    for ev in events.read() {
        let tf = transforms.get(ev.target).unwrap();
        commands.spawn((
            Text2dBundle { text: Text::from_section(format!("{}", ev.amount as i32),
                TextStyle { font_size: 24.0, color: Color::YELLOW, ..default() }),
                transform: *tf, ..default() },
            FloatingText { lifetime: Timer::from_seconds(1.0, TimerMode::Once), velocity: Vec2::Y * 50.0 },
        ));
    }
}

Modifier aggregation (base + buffs + equipment)

fn aggregate_attack(
    mut q: Query<(&BaseStats, &Buffs, &Equipment, &mut DerivedAttack)>,
) {
    for (base, buffs, eq, mut atk) in q.iter_mut() {
        let mut v = base.attack;
        v += eq.iter().map(|i| i.attack_bonus).sum::<f32>();
        v *= 1.0 + buffs.iter().map(|b| b.attack_mult).sum::<f32>();
        atk.0 = v;
    }
}

매 결정 기준

상황	Approach
Modern data-oriented engine	Bevy ECS / Unity DOTS / Unreal MASS
OOP legacy engine	Component pattern + observer for stat→visual
Multiplayer authoritative server	Server simulation, client interpolation
Animation-heavy	Skeletal animation system separate from stats

기본값: ECS — sim Components → 매 system 의 derive Visual Components → renderer 의 read-only.

🔗 Graph

• 부모: Entity Component System
• Adjacent: Bevy · Fixed Timestep

🤖 LLM 활용

언제: 매 game development, 매 simulation/render decoupling, 매 ECS pipeline 의 design. 언제 X: 매 일반 web/backend, 매 simple tool — over-engineering.

❌ 안티패턴

• Render reads sim mid-tick: 매 tearing — 매 PostUpdate 의 inject 의 사용.
• Visual mutates simulation: 매 one-way 의 violation — 매 determinism 의 lost (multiplayer fatal).
• Damage 의 main thread blocking VFX: 매 frame drop. 매 event-driven, async.
• Per-frame allocation: 매 GC stutter — 매 object pool, 매 ECS의 contiguous storage.

🧪 검증 / 중복

• Verified (Bevy 0.14 docs 2025; Unity DOTS docs; Game Engine Architecture Gregory 3rd ed).
• 신뢰도 B (synthesis from multiple engine practices).

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — full ECS injection pipeline with Bevy patterns