3Lens

The render introspection OS for three.js

Deep causal analysis, trace-based debugging, and actionable optimization for WebGL/WebGPU apps.

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🚧 Major Redesign In Progress

3Lens is undergoing a complete architectural redesign. The new system is built on 5 foundational primitives: Capture, Model, Query, Visualize, and Act + Verify. See the Architecture section for details.

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✨ Vision

3Lens is not just another metrics panel. It's a render introspection OS where every tool is a view over shared primitives:

• Deep Trace + Causal Analysis — Understand why something is slow, not just that it's slow
• Offline Diff/Regression — Compare traces across sessions, catch regressions in CI
• Resource Leak Detection — Full lifecycle tracking, not just counts
• Actionable Optimization Paths — Click a metric → see the blame chain → fix the culprit
• Multi-Context Support — First-class support for multiple renderers, scenes, cameras

📦 Package Architecture

Core Packages

Package	Description
@3lens/kernel	Event capture, entity graph, query engine, trace format
@3lens/runtime	Public API: createLens(), context registration, discovery
@3lens/devtools	Batteries-included meta-package for most users

Host Packages

Package	Description
@3lens/host-manual	Vanilla three.js (user provides renderer/scene/camera)
@3lens/host-r3f	React Three Fiber integration
@3lens/host-tres	TresJS/Vue integration
@3lens/host-worker	OffscreenCanvas/Worker support

Addon Packages

Package	Description
@3lens/addon-inspector	Entity graph browser + blame navigator
@3lens/addon-perf	Performance analysis with attribution
@3lens/addon-memory	Resource lifecycle + leak detection
@3lens/addon-diff	Frame/session/trace comparison
@3lens/addon-shader	Shader introspection

UI Packages

Package	Description
@3lens/ui-core	Framework-agnostic UI shell
@3lens/ui-web	Web Components for universal mounting

Mount Kits

Package	Description
@3lens/mount-angular	Angular service/component wrapper
@3lens/mount-react	React context/hooks wrapper
@3lens/mount-vue	Vue plugin/composables
@3lens/mount-svelte	Svelte action/component

Tooling

Package	Description
@3lens/vite-plugin	Dev server injection
@3lens/cli	Trace recording, diff, validation commands

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🚀 Quick Start (Preview)

Note: Packages are not yet published. This shows the target API.

import { createLens, manualHost, uiOverlay } from "@3lens/devtools";

const lens = createLens({
  ui: uiOverlay(),
  addons: ["inspector", "perf", "memory"],
});

lens.registerContext({
  id: "main",
  host: manualHost({ renderer, scene, camera }),
});

lens.attach();

Web Components

<script type="module">
  import '@3lens/ui-web';
  import { createLens, manualHost } from '@3lens/runtime';

  const lens = createLens();
  lens.registerContext({ id: 'main', host: manualHost({ renderer, scene, camera }) });

  const overlay = document.querySelector('three-lens-overlay');
  overlay.lens = lens;
</script>

<three-lens-overlay></three-lens-overlay>

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🏗 Architecture

┌─────────────────────────────────────────────────────────────┐
│                        Your App                             │
├─────────────────────────────────────────────────────────────┤
│  Mount Kit (optional)     │  Host Integration               │
│  @3lens/mount-react       │  @3lens/host-manual             │
│  @3lens/mount-vue         │  @3lens/host-r3f                │
│  @3lens/mount-angular     │  @3lens/host-tres               │
│  @3lens/mount-svelte      │  @3lens/host-worker             │
├─────────────────────────────────────────────────────────────┤
│                     @3lens/runtime                          │
│            createLens() • registerContext()                 │
├─────────────────────────────────────────────────────────────┤
│  Addons                   │  UI                             │
│  @3lens/addon-inspector   │  @3lens/ui-core                 │
│  @3lens/addon-perf        │  @3lens/ui-web                  │
│  @3lens/addon-memory      │                                 │
│  @3lens/addon-diff        │                                 │
│  @3lens/addon-shader      │                                 │
├─────────────────────────────────────────────────────────────┤
│                      @3lens/kernel                          │
│         Capture • Entity Graph • Query • Trace              │
└─────────────────────────────────────────────────────────────┘

The 5 Foundational Primitives

1. Capture — Authoritative event stream (render events, resource lifecycle)
2. Model — Unified typed dependency graph (entities + relationships)
3. Query — Tools query the model, not the renderer directly
4. Visualize — Views are projections of queries
5. Act + Verify — Actions produce events, verification shows diffs

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📁 Project Structure

packages/
├── core/                 # Core packages
│   ├── kernel/          # Event capture, entity graph, queries, trace
│   ├── runtime/         # Public API, createLens, hosts, addons
│   └── devtools/        # Batteries-included meta-package
├── hosts/               # Runtime integrations
│   ├── manual/          # Vanilla three.js
│   ├── r3f/             # React Three Fiber
│   ├── tres/            # TresJS/Vue
│   └── worker/          # OffscreenCanvas/Worker
├── addons/              # Feature modules
│   ├── inspector/       # Entity browser, blame navigator
│   ├── perf/            # Performance analysis
│   ├── memory/          # Resource lifecycle, leak detection
│   ├── diff/            # Frame/trace comparison
│   └── shader/          # Shader introspection
├── ui/                  # UI packages
│   ├── core/            # Framework-agnostic UI shell
│   └── web/             # Web Components
├── mounts/              # Framework mount kits
│   ├── angular/
│   ├── react/
│   ├── vue/
│   └── svelte/
└── tools/               # Build & CLI tools
    ├── cli/
    └── vite-plugin/

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🛠️ Development Setup

Prerequisites

• Node.js 20+
• pnpm 9+

Clone and Install

git clone https://github.com/adriandarian/3Lens.git
cd 3Lens
pnpm install

Build All Packages

pnpm build

Run Tests

pnpm test

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📋 Project Status

Component	Status
Kernel (capture, graph, query, trace)	✅ Implemented
Runtime (createLens, hosts, addons)	✅ Implemented
Host: Manual	✅ Implemented
Host: R3F, TresJS, Worker	🔜 Stub
Addons: Inspector	✅ Implemented
Addons: Perf, Memory, Diff, Shader	🔜 Stub
UI: Core	✅ Implemented
UI: Web Components	✅ Implemented
Mount Kits	🔜 Stub
CLI	✅ Implemented
Vite Plugin	✅ Implemented
Examples	🔜 Not Started
Documentation	🔜 In Progress

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📖 Documentation

• Architecture Guide — Project philosophy and design principles
• Contracts — System invariants and guarantees
• Plugin API — Building third-party addons
• Skills & Commands — CLI commands and programmatic APIs

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🤝 Contributing

Contributions are welcome! Please see CONTRIBUTING.md for guidelines.

# Run tests
pnpm test

# Type check
pnpm typecheck

# Lint
pnpm lint

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📄 License

MIT © 3Lens Contributors

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_{Built with ❤️ for the three.js community}