three.js vs PlayCanvas

Agent access

1. ai-native userPoint an agent at llms.txt or agent-oriented docs

   weight 2 · round drawn
   three.js✓fullprobed9/10

   three.js publishes a llms.txt at its site root (HTTP 200 confirmed by probe) with an explicit 'Instructions for Large Language Models' section and a 363KB llms-full.txt covering complete docs, giving agents a direct machine-readable path. missing for 10: independent/community confirmation that agents actually use this llms.txt successfully in practice, and per-page markdown docs are hash-routed rather than statically addressable.

   • [probe] “PROBE llms.txt: HTTP 200 at https://threejs.org/llms.txt # Three.js > Three.js is a cross-browser JavaScript library for creating 3D graphi…”
   • [probe] “PROBE runtime (recorded 2026-09-15): threejs.org publishes llms.txt at the site root pointing to a docs llms.txt that carries a literal '## …”
   • [claimed-docs] “TSL benefits: - Works with both WebGL and WebGPU backends - No string manipulation or onBeforeCompile hacks”
   • [claimed-docs] “TSL benefits: - Works with both WebGL and WebGPU backends - No string manipulation or onBeforeCompile hacks - Type-safe, composable shader n…”

   proof ↗⚑ flag

   PlayCanvas✓fullprobed9/10

   A working llms.txt confirmed via HTTP 200 probe plus an unusually large llms-full.txt (2MB) of complete docs is directly served at developer.playcanvas.com, satisfying the exact story of pointing an agent at llms.txt/agent-oriented docs. This is corroborated by both docs claims and independent runtime probes, not just vendor assertion. Missing for 10: no independent third-party (non-probe) report of an agent actually consuming the file successfully in a real workflow.

   • [probe] “PROBE llms.txt: HTTP 200 at https://developer.playcanvas.com/llms.txt # PlayCanvas Developer Documentation > PlayCanvas is an open-source W…”
   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”

   proof ↗⚑ flag

2. ai-native userRun the product headlessly / in CI for automation

   weight 2 · round drawn
   three.js—none0/10

   Three.js is fundamentally a browser WebGL/WebGPU library requiring a GPU-backed rendering context; the evidence pack contains no mention of headless rendering, Node.js server-side use, headless-gl/puppeteer integration, or CI automation support. This is a fair question for a rendering engine (other engines in this space document headless CI paths), so absence of evidence means 'none' rather than 'na'.

   ⚑ flag

   PlayCanvas—none0/10

   Evidence shows the engine is npm-installable and there's an Editor MCP server, but the MCP server explicitly requires 'an open PlayCanvas Editor session' (interactive), and no evidence describes headless rendering, CI pipelines, or server-side/automated execution of the engine or editor without a live browser/editor session.

   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [github] “npm install playcanvas”
   • [community] “When I was working at a mobile game studio, we looked at this as an engine for a project. At the time we decided not to go with it since all…”

   proof ↗⚑ flag

3. ai-native userConnect an agent via an official MCP server

   weight 3 · round to PlayCanvas
   three.js—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

   PlayCanvas✓fullprobed9/10

   PlayCanvas documents and ships an official, first-party MCP server (`@playcanvas/editor-mcp-server`, npm-published, official org repo) that connects AI assistants to a live Editor session to modify project data and verify results via the viewport, confirmed both in docs and runtime probes. Missing for 10: independent third-party hands-on validation of the MCP server beyond vendor docs/probe.

   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [probe] “official MCP server documented at https://developer.playcanvas.com/user-manual/editor/mcp-server/”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”

   proof ↗⚑ flag

4. ai-native userUse an official CLI

   weight 2 · round to PlayCanvas
   three.js—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

   PlayCanvas~partialclaimed4/10

   PlayCanvas ships an official `create-playcanvas` CLI for scaffolding Vite/TypeScript projects, which an AI agent could invoke, but the docs describe it purely as a project scaffolder with no explicit AI-native/agentic features (non-interactive flags, scripting API, automation hooks) and no independent confirmation of agent usage. Missing for 10: documentation of CLI flags/JSON output for automation, evidence of AI-agent usage, and any tie-in with the MCP server workflow.

   • [claimed-docs] “Use `create-playcanvas` to scaffold a Vite and TypeScript project for the Engine, React, or Web Components from one of 12 runnable starters.”

   proof ↗⚑ flag

5. ai-native userDrive the product through a documented public API

   weight 3 · round to PlayCanvas
   three.js~partialprobed6/10

   three.js exposes a well-documented JS API (WebGLRenderer/WebGPURenderer, TSL, GLTFLoader, controls) and even publishes llms.txt/llms-full.txt files explicitly aimed at LLM consumption, which supports AI-native driving of the library via npm. However this is a client-side JS library API, not a service with an OpenAPI/REST spec or an MCP server, and probes confirm no OpenAPI endpoints and no official MCP server exist. missing for 10: OpenAPI/machine-readable API spec, official MCP server, per-page static doc URLs (docs are hash-routed, only llms.txt is the structured machine path).

   • [probe] “PROBE llms.txt: HTTP 200 at https://threejs.org/llms.txt # Three.js > Three.js is a cross-browser JavaScript library for creating 3D graphi…”
   • [probe] “PROBE runtime (recorded 2026-09-15): threejs.org publishes llms.txt at the site root pointing to a docs llms.txt that carries a literal '## …”
   • [probe] “PROBE openapi: all candidate paths 404 (https://threejs.org/openapi.json, https://threejs.org/swagger.json, https://threejs.org/api/openapi.…”
   • [claimed-docs] “TSL benefits: - Works with both WebGL and WebGPU backends - No string manipulation or onBeforeCompile hacks”
   • [claimed-docs] “[GLTFLoader](https://threejs.org/docs/#examples/en/loaders/GLTFLoader)”
   • [github] “const renderer = new THREE.WebGLRenderer( { antialias: true } ); renderer.setSize( width, height );”

   proof ↗⚑ flag

   PlayCanvas✓fullprobed7/10

   PlayCanvas exposes a documented scriptable Editor API for automating/customizing the Editor environment (api.playcanvas.com/editor/) plus an official, npm-published Editor MCP Server explicitly built for AI assistants to modify project data and verify results, alongside a standalone Engine API and llms.txt docs for AI consumption. This gives AI-native users multiple documented, programmatic ways to drive the product. Missing for 10: a formal OpenAPI/REST spec (probe found only 404s for openapi/swagger endpoints) and independent third-party confirmation of API-driven automation success.

   • [claimed-docs] “This module is essential for developers looking to streamline their workflow, create custom editing tools, or integrate external data and sy…”
   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [claimed-docs] “Build applications against the Engine directly. Learn how to use the Engine standalone.”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”
   • [probe] “PROBE openapi: all candidate paths 404 (https://developer.playcanvas.com/openapi.json, https://developer.playcanvas.com/swagger.json, https:…”
   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”

   proof ↗⚑ flag

6. ai-native userBuild against official SDKs

   weight 2 · round to PlayCanvas
   three.js~partialprobed5/10

   three.js publishes an llms.txt/llms-full.txt with explicit LLM instructions and is consumable directly via npm, and it is an official, well-documented SDK (WebGL/WebGPU renderers, TSL, GLTFLoader, controls). However, this is a library/API rather than an 'agentic' SDK with tool-calling or agent-specific integration hooks, and there is no official MCP server or agent-oriented tooling beyond docs formatted for LLM consumption. missing for 10: no agent-specific SDK features (e.g., function-calling schemas, MCP server), no independent verification of llms.txt actually improving agent code generation, human docs are hash-routed rather than crawlable per-page.

   • [probe] “PROBE runtime (recorded 2026-09-15): threejs.org publishes llms.txt at the site root pointing to a docs llms.txt that carries a literal '## …”
   • [probe] “PROBE llms.txt: HTTP 200 at https://threejs.org/llms.txt # Three.js > Three.js is a cross-browser JavaScript library for creating 3D graphi…”
   • [claimed-docs] “TSL benefits: - Works with both WebGL and WebGPU backends - No string manipulation or onBeforeCompile hacks”
   • [claimed-docs] “[GLTFLoader](https://threejs.org/docs/#examples/en/loaders/GLTFLoader)”
   • [probe] “PROBE runtime (recorded 2026-09-15): `npm view three version` → 0.186.0, and the public npm downloads API reports 12,206,532 weekly download…”

   proof ↗⚑ flag

   PlayCanvas✓fullprobed8/10

   PlayCanvas publishes multiple official SDKs — the core Engine (npm `playcanvas`), React and Web Components bindings, a `create-playcanvas` scaffolding CLI, a scriptable Editor API, and an official npm-published Editor MCP server for AI automation — all documented and runtime-verified. Community discussion confirms it integrates with standard JS/React workflows, though it also notes some dev-experience friction unrelated to SDK availability. Missing for 10: independent hands-on developer reports specifically validating SDK usage/quality, and a public OpenAPI/versioned reference (probe found only 404s for openapi.json).

   • [claimed-docs] “Use `create-playcanvas` to scaffold a Vite and TypeScript project for the Engine, React, or Web Components from one of 12 runnable starters.”
   • [claimed-docs] “Build applications against the Engine directly. Learn how to use the Engine standalone.”
   • [claimed-docs] “This module is essential for developers looking to streamline their workflow, create custom editing tools, or integrate external data and sy…”
   • [claimed-docs] “Already use React, want declarative 3D scenes, or need to integrate 3D into React apps”
   • [github] “npm install playcanvas”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”
   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”
   • [community] “You can use it in conjunction with pretty much any other JS framework available.”

   proof ↗⚑ flag

Agentic features

1. ai-native userGet AI-generated insights and suggestions from my data inside the product

   weight 2 · round to PlayCanvas
   three.js—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

   PlayCanvas~partialprobed4/10

   PlayCanvas ships an official Editor MCP server that lets connected AI assistants read and modify project data and verify results in the viewport, which could be used to generate suggestions/insights from a user's scene data, but there is no evidence of a native, built-in AI insights/recommendations feature (e.g., analytics, optimization suggestions) inside the product itself. Missing for 10: dedicated AI-insights UI or documented use-case of the MCP server producing analytical suggestions, independent corroboration of this workflow in practice.

   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [probe] “official MCP server documented at https://developer.playcanvas.com/user-manual/editor/mcp-server/”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”

   proof ↗⚑ flag

2. ai-native userSet up automations that run autonomously in the background

   weight 2 · round to PlayCanvas
   three.js—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

   PlayCanvas~partialprobed4/10

   PlayCanvas ships an official Editor MCP server that lets AI assistants programmatically modify project data, but it explicitly requires 'an open PlayCanvas Editor session' rather than running as an independent, scheduled, or background process — this is closer to AI-assisted live editing than autonomous background automation. Missing for 10: evidence of scheduled/triggered jobs, headless/background execution without a live editor session, or any autonomous agent loop running unattended.

   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [probe] “official MCP server documented at https://developer.playcanvas.com/user-manual/editor/mcp-server/”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”

   proof ↗⚑ flag

3. ai-native userDelegate tasks to a built-in AI assistant inside the product

   weight 3 · round to PlayCanvas
   three.js—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

   PlayCanvas~partialprobed5/10

   PlayCanvas does not ship a built-in AI assistant embedded in its UI; instead it exposes an official Editor MCP server that lets external AI assistants (e.g. Claude) connect to an open Editor session and modify/inspect project data via the viewport, effectively allowing task delegation to AI, but the assistant itself lives outside the product rather than inside it. Missing for 10: a first-party, in-product AI assistant UI/chat surface, and any hands-on/community verification that delegation via MCP works well in practice.

   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [probe] “official MCP server documented at https://developer.playcanvas.com/user-manual/editor/mcp-server/”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”

   proof ↗⚑ flag

4. ai-native userOperate the product with natural-language commands

   weight 2 · round to PlayCanvas
   three.js~partialprobed3/10

   three.js publishes an llms.txt/llms-full.txt specifically to let AI coding agents generate code that drives the library, which is a step toward AI-native operability, but there is no natural-language command interface, chat layer, or MCP server that lets a user directly 'command' the renderer in natural language — an agent still has to write and run JavaScript. Missing for 10: a direct natural-language control layer, an MCP server or agent API, and independent evidence of agents successfully operating three.js purely via NL commands.

   • [probe] “PROBE runtime (recorded 2026-09-15): threejs.org publishes llms.txt at the site root pointing to a docs llms.txt that carries a literal '## …”
   • [probe] “PROBE llms.txt: HTTP 200 at https://threejs.org/llms.txt # Three.js > Three.js is a cross-browser JavaScript library for creating 3D graphi…”
   • [claimed-docs] “TSL benefits: - Works with both WebGL and WebGPU backends - No string manipulation or onBeforeCompile hacks”

   proof ↗⚑ flag

   PlayCanvas~partialprobed6/10

   PlayCanvas ships an official, npm-published Editor MCP Server that lets AI assistants modify project data and verify results via the viewport, which is a genuine natural-language/agentic control surface for the Editor. However, this only covers Editor operations, not the runtime Engine or broader workflows, and there's no independent/hands-on evidence of it being used successfully in practice. missing for 10: community/hands-on validation of the MCP server in real workflows, evidence of natural-language control over the Engine/runtime (not just Editor), and broader agentic tool coverage beyond the single MCP server.

   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [probe] “official MCP server documented at https://developer.playcanvas.com/user-manual/editor/mcp-server/”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”

   proof ↗⚑ flag

Api quality

1. ai-native userExplore an interactive API reference with runnable examples

   weight 2 · round to three.js
   three.js~partialprobed6/10

   three.js has a documented interactive examples gallery (threejs.org/examples) and an extensive docs/manual with API references, plus an llms.txt/llms-full.txt tailored for AI agents to consume the API reference programmatically. However, the examples are not runnable/editable inline within the docs reference itself in an AI-native interactive way, there's no API playground or embedded live code editor tied to reference pages, and human doc pages are hash-routed rather than having stable per-page URLs, limiting agentic navigation. missing for 10: inline runnable/editable examples embedded in API reference pages, stable per-page doc URLs for agent navigation, and any dedicated interactive playground/sandbox tool.

   • [claimed-docs] “three.js examples”
   • [claimed-docs] “[docs](manual/#en/creating-a-scene) [examples](examples/#webgl_animation_keyframes)”
   • [probe] “PROBE runtime (recorded 2026-09-15): threejs.org publishes llms.txt at the site root pointing to a docs llms.txt that carries a literal '## …”
   • [probe] “PROBE llms.txt: HTTP 200 at https://threejs.org/llms.txt # Three.js > Three.js is a cross-browser JavaScript library for creating 3D graphi…”
   • [community] “the three.js examples are good (if a little sloppy in coding style). I think the main thing that helps is some kind of previous knowledge ab…”

   proof ↗⚑ flag

   PlayCanvas—none0/10

   Evidence shows PlayCanvas has API docs (api.playcanvas.com/editor), llms.txt full docs, and starter templates, but no evidence of an interactive API reference page with embedded runnable code examples akin to a live sandbox integrated into the reference itself.

   ⚑ flag

2. ai-native userDownload a machine-readable API spec (OpenAPI or equivalent)

   weight 2 · round to three.js
   three.js~partialprobed5/10

   Three.js has no OpenAPI/Swagger spec (explicit probe of openapi.json/swagger.json paths all 404), but it does publish an 'equivalent' machine-readable artifact for AI consumption: a root-level llms.txt with an explicit 'Instructions for Large Language Models' section and a 363KB llms-full.txt covering the full API surface. This is a documentation-style machine-readable spec rather than a structured, typed API schema (no parameter/type schema, no endpoint-like structure). Missing for 10: a structured schema format (OpenAPI-equivalent with typed signatures), and any indication the llms.txt is treated as a formal versioned spec rather than prose docs.

   • [probe] “PROBE llms.txt: HTTP 200 at https://threejs.org/llms.txt # Three.js > Three.js is a cross-browser JavaScript library for creating 3D graphi…”
   • [probe] “PROBE openapi: all candidate paths 404 (https://threejs.org/openapi.json, https://threejs.org/swagger.json, https://threejs.org/api/openapi.…”
   • [probe] “PROBE runtime (recorded 2026-09-15): threejs.org publishes llms.txt at the site root pointing to a docs llms.txt that carries a literal '## …”

   proof ↗⚑ flag

   PlayCanvas—none0/10

   Explicit probe evidence shows no OpenAPI/Swagger spec exists at any expected path (all candidates 404); while llms.txt and an Editor API doc site exist, there is no machine-readable API spec download offered.

   • [probe] “PROBE openapi: all candidate paths 404 (https://developer.playcanvas.com/openapi.json, https://developer.playcanvas.com/swagger.json, https:…”

   proof ↗⚑ flag

3. ai-native userTest against a sandbox environment without touching production data

   weight 1 · round to PlayCanvas
   three.js—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

   PlayCanvas~partialclaimed3/10

   PlayCanvas documents Checkpoints for snapshotting/rolling back a project and an MCP server that acts on 'an open PlayCanvas Editor session,' which offers some safety net against irreversible changes, but there is no explicit sandbox/staging environment distinct from production data that an AI agent could test against. missing for 10: dedicated sandbox/staging project mode, explicit production-vs-test data separation, and evidence that MCP or automation actions can't touch the live production project.

   • [claimed-docs] “Checkpoints — Snapshot your project at any point and roll back if needed”
   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [claimed-docs] “With live editing, you can tweak materials, adjust positions, and even modify scripts while your application runs.”

   proof ↗⚑ flag

4. ai-native userRely on versioned APIs with a documented deprecation policy

   weight 2 · round to three.js
   three.js~partialprobed4/10

   There is a Migration Guide and per-release notes documenting breaking changes between versions (e.g. 185→186), and npm shows a clear version number (0.186.0), but nothing describes a formal deprecation policy (notice periods, stable API guarantees, semver commitments) — three.js is known for frequent breaking changes on its own rolling release cadence. missing for 10: explicit deprecation policy statement, semver/API-stability guarantees, notice period before removals.

   • [claimed-docs] “[Migration Guide](/mrdoob/three.js/wiki/Migration-Guide)”
   • [claimed-docs] “https://github.com/mrdoob/three.js/wiki/Migration-Guide#185--186”
   • [probe] “PROBE runtime (recorded 2026-09-15): `npm view three version` → 0.186.0, and the public npm downloads API reports 12,206,532 weekly download…”

   proof ↗⚑ flag

   PlayCanvas—none0/10

   No evidence pack item mentions API versioning semantics or a documented deprecation policy; the OpenAPI probe returned 404s and docs only describe scripting formats, editor features, and an MCP server, not stability guarantees for the API surface.

   • [probe] “PROBE openapi: all candidate paths 404 (https://developer.playcanvas.com/openapi.json, https://developer.playcanvas.com/swagger.json, https:…”

   proof ↗⚑ flag

Agent editor

1. ai-native userAn agent can drive the editor and project programmatically — create scenes and nodes, edit properties, trigger builds — through a documented scriptable interface

   weight 3 · round to PlayCanvas
   three.js~partialprobed4/10

   Three.js's core JS API lets an agent create scenes, nodes, meshes, and materials and edit properties programmatically (documented in llms.txt for LLM consumption), but this is just using the library — there's no evidence of a documented scripting/automation interface for the standalone three.js editor app itself, nor any 'trigger build' concept or API. Missing for 10: documented editor automation/scripting API, evidence of programmatic control of the editor UI, and any build/export trigger mechanism.

   • [claimed-docs] “three.js editor”
   • [probe] “PROBE runtime (recorded 2026-09-15): threejs.org publishes llms.txt at the site root pointing to a docs llms.txt that carries a literal '## …”
   • [github] “This code creates a scene, a camera, and a geometric cube, and it adds the cube to the scene. It then creates a `WebGL` renderer for the sce…”
   • [claimed-docs] “[docs](manual/#en/creating-a-scene) [examples](examples/#webgl_animation_keyframes)”

   proof ↗⚑ flag

   PlayCanvas✓fullprobed8/10

   PlayCanvas ships an official, npm-published Editor MCP server that lets AI agents connect to an open Editor session, modify project data, and verify results, plus a separate documented scriptable Editor API (api.playcanvas.com/editor) for programmatic scene/node/property manipulation and automation. This directly satisfies the story of an agent driving the editor programmatically through a documented interface. Missing for 10: no independent/hands-on community report of an agent actually using the MCP server end-to-end, and no explicit documentation of triggering builds via this interface.

   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [claimed-docs] “This module is essential for developers looking to streamline their workflow, create custom editing tools, or integrate external data and sy…”
   • [probe] “official MCP server documented at https://developer.playcanvas.com/user-manual/editor/mcp-server/”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”
   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”

   proof ↗⚑ flag

Codegen

1. ai-native userLLM-generated code mostly works on the first try — stable, well-documented APIs with abundant public examples the models have seen

   weight 2 · round drawn
   three.js~partialprobed6/10

   Three.js is hugely popular (12M weekly npm downloads) with abundant public examples and even a dedicated llms.txt/llms-full.txt tailored for LLM consumption, which strongly favors first-try LLM code generation. However, community evidence and the docs themselves point to real friction: frequent breaking API changes requiring per-version migration guides, explicit warnings to use 'CORRECT - modern pattern' import maps (implying old LLM-trained patterns break), and hands-on reports that seemingly simple tasks (loading a model) were unexpectedly hard, undermining 'mostly works on the first try.' Missing for 10: independent benchmark/report of LLM-generated three.js code success rate, and stronger evidence that API stability (not just doc richness) prevents version-mismatch failures.

   • [probe] “PROBE runtime (recorded 2026-09-15): `npm view three version` → 0.186.0, and the public npm downloads API reports 12,206,532 weekly download…”
   • [probe] “PROBE runtime (recorded 2026-09-15): threejs.org publishes llms.txt at the site root pointing to a docs llms.txt that carries a literal '## …”
   • [claimed-docs] “CORRECT - modern pattern (always use latest version): html <script type="importmap">”
   • [claimed-docs] “[Migration Guide](/mrdoob/three.js/wiki/Migration-Guide)”
   • [community] “I've tried to follow three.js's own tutorials, and slip into coma every time. These are a vast improvement!”
   • [community] “I was super excited to use Three.js and thought it would be easy to do what I wanted. What I wanted to do was load a simple .obj model and d…”
   • [community] “there are some function signatures that don't match what's in the code using @types/three, and mrdoob does not want to maintain this. This g…”

   proof ↗⚑ flag

   PlayCanvas~partialprobed6/10

   PlayCanvas offers strong LLM-friendly infrastructure — a dedicated llms.txt/llms-full.txt (over 2MB of docs), a stable, long-standing npm-published engine (2.22.2, 48k weekly downloads) with abundant public code examples and community history, plus scripting API docs — all of which support an LLM having 'seen' the API. However, community threads note real dev-experience quirks and unusual design choices that could trip up naive LLM-generated code, and there's no direct hands-on evidence of first-try LLM code generation success rates. Missing for 10: independent benchmark or testimonial confirming LLM-generated PlayCanvas code works correctly on first try, and no discussion of API stability/breaking-change history that would affect training-data staleness.

   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”
   • [probe] “PROBE llms.txt: HTTP 200 at https://developer.playcanvas.com/llms.txt # PlayCanvas Developer Documentation > PlayCanvas is an open-source W…”
   • [github] “npm install playcanvas”
   • [community] “That issue was opened in 2022. Honestly if you really get into the nitty gritty of PC it becomes quickly apparent there's some very strange …”
   • [community] “I think Playcanvas would do well to focus on the basics, like being able to export/import variables in the standard js way, being able to de…”

   proof ↗⚑ flag

Copilot

1. ai-native userAn official AI assistant inside the engine helps with engine tasks — generating scripts, answering API questions, scaffolding scenes or assets

   weight 2 · round to PlayCanvas
   three.js—none0/10

   Evidence shows only LLM-friendly documentation (llms.txt) and no in-engine AI assistant, chat copilot, or code-generation assistant feature; probe explicitly notes no MCP server or agent integration exists, official or community.

   • [probe] “PROBE runtime (recorded 2026-09-15): threejs.org publishes llms.txt at the site root pointing to a docs llms.txt that carries a literal '## …”
   • [probe] “PROBE llms.txt: HTTP 200 at https://threejs.org/llms.txt # Three.js > Three.js is a cross-browser JavaScript library for creating 3D graphi…”

   proof ↗⚑ flag

   PlayCanvas~partialprobed6/10

   PlayCanvas ships an official, npm-published Editor MCP Server that lets external AI assistants connect to a live Editor session to modify project data, script entities, and verify changes via the viewport—directly enabling AI-assisted script generation and scene/asset scaffolding (playcanvas-docs-6, playcanvas-probe-rt-1). However, this is an MCP bridge for third-party assistants rather than a built-in chat/assistant panel inside the engine UI, and there's no dedicated in-engine API Q&A assistant beyond the llms.txt docs feed. Missing for 10: a native in-editor chat/assistant UI, and explicit evidence of it answering free-form API questions rather than just executing structured edits.

   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [probe] “official MCP server documented at https://developer.playcanvas.com/user-manual/editor/mcp-server/”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”
   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”

   proof ↗⚑ flag

Formats

1. technical artistStandard interchange formats — glTF, FBX, USD — import cleanly

   weight 2 · round to three.js
   three.js~partialcommunity4/10

   Only GLTFLoader is explicitly evidenced as a documented import path; there is no mention of FBX or USD loaders in the evidence pack, and a community report describes friction loading even a simple OBJ model, undercutting the 'imports cleanly' framing. Missing for 10: FBXLoader/USDLoader documentation or examples, first-party guidance on interchange-format fidelity, and independent confirmation that glTF/FBX/USD assets import without manual fixes.

   • [claimed-docs] “[GLTFLoader](https://threejs.org/docs/#examples/en/loaders/GLTFLoader)”
   • [community] “I was super excited to use Three.js and thought it would be easy to do what I wanted. What I wanted to do was load a simple .obj model and d…”

   proof ↗⚑ flag

   PlayCanvas—none0/10

   The evidence pack contains no mention of glTF, FBX, or USD import support, nor any asset-pipeline/import documentation; it covers editor, scripting, MCP server, and community sentiment unrelated to file format import.

   ⚑ flag

Import

1. technical artistAsset import is automatable — import hooks, presets, and pipeline scripts process incoming assets without hand-clicking each one

   weight 2 · round to PlayCanvas
   three.js—none0/10

   three.js is a rendering library with a GLTFLoader and asset loaders, but there is no evidence of automatable asset-import pipelines, import hooks, presets, or scripted batch-processing of incoming assets — everything in the evidence pack concerns runtime rendering APIs, TSL/WebGPU, and manual loader usage rather than pipeline automation.

   • [claimed-docs] “[GLTFLoader](https://threejs.org/docs/#examples/en/loaders/GLTFLoader)”
   • [github] “The current builds only include WebGL and WebGPU renderers but SVG and CSS3D renderers are also available as addons.”

   proof ↗⚑ flag

   PlayCanvas~partialcommunity3/10

   The Editor API is explicitly billed for scripting custom tools and integrating external systems (playcanvas-docs-9), and the community references playcanvas-sync for mapping project assets to a local filesystem (playcanvas-comm-10) and the MCP server for programmatic project data changes (playcanvas-docs-6), all of which imply some automation capability. However, there is no documented import-hook system, asset presets, or a dedicated pipeline-scripting API specifically for processing incoming assets automatically. Missing for 10: explicit asset import hooks, configurable import presets, documented pipeline scripts triggered on asset ingestion, and independent confirmation these tools eliminate manual per-asset clicking.

   • [claimed-docs] “This module is essential for developers looking to streamline their workflow, create custom editing tools, or integrate external data and sy…”
   • [community] “I recommend checking out the newly released playcanvas-sync tools which let you map your PlayCanvas project's assets to your local machine's…”
   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”

   proof ↗⚑ flag

Marketplace

1. game developerA large asset store or package ecosystem gives me ready-made models, tools, and plugins

   weight 2 · round drawn
   three.js—none0/10

   Evidence only shows three.js's own built-in addons (GLTFLoader, OrbitControls, editor, devtools) and npm package popularity, not a third-party asset store or plugin marketplace comparable to Unity/Unreal ecosystems; community commentary even notes basic model loading (.obj) was painful. missing for 10: any evidence of a dedicated asset store, marketplace, or curated third-party plugin ecosystem for game assets/tools.

   • [claimed-docs] “[GLTFLoader](https://threejs.org/docs/#examples/en/loaders/GLTFLoader)”
   • [claimed-docs] “[OrbitControls](https://threejs.org/docs/#examples/en/controls/OrbitControls) - [TransformControls](https://threejs.org/docs/#examples/en/co…”
   • [claimed-docs] “three.js editor”
   • [claimed-docs] “[devtools](https://chromewebstore.google.com/detail/threejs-devtools/jechbjkglifdaldbdbigibihfaclnkbo)”
   • [community] “I was super excited to use Three.js and thought it would be easy to do what I wanted. What I wanted to do was load a simple .obj model and d…”
   • [probe] “PROBE runtime (recorded 2026-09-15): `npm view three version` → 0.186.0, and the public npm downloads API reports 12,206,532 weekly download…”

   proof ↗⚑ flag

   PlayCanvas—none0/10

   The evidence pack shows PlayCanvas has an editor, engine, scripting system, MCP server, and npm-published engine, but nowhere mentions an asset store, marketplace, or plugin/package ecosystem for ready-made models or tools. No community or docs citation references anything resembling a store of third-party assets or plugins.

   ⚑ flag

1. ai-native userPerform bulk operations across many items at once

   weight 2 · round to PlayCanvas
   three.js—none0/10

   No evidence describes batch/bulk APIs (e.g., instancing, scene-graph batch edits) or automation tooling for operating on many items at once; the evidence pack only covers renderer setup, TSL, loaders, and controls.

   ⚑ flag

   PlayCanvas~partialprobed4/10

   PlayCanvas exposes a scriptable Editor API (api.playcanvas.com/editor) explicitly for building custom editing tools and integrating external data, and an official MCP server that lets AI assistants modify project data programmatically — both imply automation potential across many assets, but neither doc explicitly describes bulk/batch operations (e.g., multi-entity edits, batch asset import) or gives a hands-on example of many-item automation. Missing for 10: explicit bulk-edit/batch API examples, documented multi-item scripting workflows, and independent confirmation of large-scale automation via the MCP server or Editor API.

   • [claimed-docs] “This module is essential for developers looking to streamline their workflow, create custom editing tools, or integrate external data and sy…”
   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”

   proof ↗⚑ flag

2. ai-native userDefine rules that trigger actions automatically on events

   weight 3 · round drawn
   three.js—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

   PlayCanvas—none0/10

   The evidence pack covers scripting syntax, editor collaboration, physics components, and the MCP server for AI-assisted project editing, but contains no documentation of an explicit event/rule system where users can define triggers that automatically fire actions (e.g., event listeners, condition-action bindings) for automation purposes. Missing for 10: documentation of an event-trigger/rule engine, examples of defining conditional automation, and evidence tying this to AI-native workflows.

   ⚑ flag

3. ai-native userVersion, review, and roll back my automations

   weight 1 · round to PlayCanvas
   three.js—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

   PlayCanvas~partialcommunity5/10

   PlayCanvas Editor has a Checkpoints feature to snapshot a project and roll back, which covers basic versioning/rollback of editor state (including changes made via the MCP-driven AI automation), but there's no documented diff/review workflow for automations and community feedback explicitly flags the lack of standard source-control integration as a pain point. missing for 10: dedicated review/diff tooling for automation changes, git-style commit history, and any evidence that checkpoints integrate specifically with AI-driven MCP edits.

   • [claimed-docs] “Checkpoints — Snapshot your project at any point and roll back if needed”
   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [community] “I think Playcanvas would do well to focus on the basics, like being able to export/import variables in the standard js way, being able to de…”

   proof ↗⚑ flag

2d

1. game developer2D is a first-class workflow — sprites, tilemaps, 2D physics — not a 3D afterthought

   weight 2 · round drawn
   three.js—none0/10

   The evidence pack shows three.js is positioned and documented purely as a 3D graphics library (WebGL/WebGPU renderers, TSL shaders, GLTFLoader, OrbitControls) with no mention of sprites, tilemaps, or 2D physics as first-class citizens; 2D is at best an afterthought achievable via workarounds, consistent with community comments about needing workarounds for things it wasn't built for.

   • [probe] “PROBE llms.txt: HTTP 200 at https://threejs.org/llms.txt # Three.js > Three.js is a cross-browser JavaScript library for creating 3D graphi…”
   • [github] “The current builds only include WebGL and WebGPU renderers but SVG and CSS3D renderers are also available as addons.”
   • [claimed-docs] “**Use WebGPURenderer** when you need: - Custom shaders/materials using TSL (Three.js Shading Language) - Compute shaders - Advanced node-bas…”
   • [community] “Three.js is insane, in a good way. Great abstraction of WebGL, very user friendly, and surprisingly few things that it can't do, as long as …”

   proof ↗⚑ flag

   PlayCanvas—none0/10

   Evidence pack covers 3D features (rigidbody/collision physics, Gaussian Splatting, Engine, Editor) but contains no mention of sprites, tilemaps, or a 2D physics system — PlayCanvas is documented here purely as a 3D-first engine. This is a fair question for a game engine, but no evidence supports a first-class 2D workflow, so it's 'none' rather than 'na'.

   • [claimed-docs] “The rigidbody component decides how an entity moves, the collision component gives it a physical shape, and the alpha joint component constr…”
   • [github] “Gaussian Splatting - First-class support for loading and rendering 3D Gaussian Splats”

   proof ↗⚑ flag

Performance

1. game developerProfile and scale — a real profiler, plus data-oriented paths (ECS, jobs, instancing) when scenes get heavy

   weight 2 · round drawn
   three.js—none0/10

   No evidence of a built-in profiler, ECS, job system, or GPU/CPU instancing tooling in the pack — only renderer setup, TSL/WebGPU shading, loaders, and controls are documented. Three.js is a rendering library, not a full engine, so profiling and data-oriented scaling primitives fall to external tools (Chrome DevTools extension is mentioned but that's a generic browser profiler, not a real-time engine profiler), and no ECS/jobs/instancing capability is cited.

   • [claimed-docs] “[devtools](https://chromewebstore.google.com/detail/threejs-devtools/jechbjkglifdaldbdbigibihfaclnkbo)”

   proof ↗⚑ flag

   PlayCanvas—none0/10

   The evidence pack contains no mention of a profiler, ECS architecture, job/worker system, or GPU instancing for scaling heavy scenes — only physics components, Gaussian splatting, and editor/collab features are documented. This is a fair axis for any game engine, but PlayCanvas's pack simply doesn't address it.

   ⚑ flag

Physics

1. game developerBuilt-in physics — rigid bodies, collisions, raycasts — works out of the box

   weight 2 · round to PlayCanvas
   three.js—none0/10

   three.js is a rendering library — no evidence of any built-in physics engine (rigid bodies, collisions, raycasts as physics) shipped out of the box; evidence only covers rendering (WebGL/WebGPU), loaders, and controls. Raycaster exists in three.js for picking but no physics/collision system is documented, and physics is a well-known gap requiring third-party libraries like Cannon.js or Ammo.js.

   ⚑ flag

   PlayCanvas~partialcommunity6/10

   Docs confirm built-in rigidbody, collision, and joint components enabling physics simulation out of the box (playcanvas-docs-8), and community sources corroborate PlayCanvas as a capable, well-designed engine used in shipped games. However, raycasts are not explicitly mentioned, and there's no hands-on evidence or tutorial demonstrating physics working smoothly without setup friction (e.g., Ammo.js/physics engine integration steps). Missing for 10: explicit raycast documentation, independent hands-on confirmation of zero-config physics setup, and detail on which physics backend is bundled vs. requires separate install.

   • [claimed-docs] “The rigidbody component decides how an entity moves, the collision component gives it a physical shape, and the alpha joint component constr…”
   • [community] “THREE.js is very low-level framework, while PlayCanvas additionally to low-level engine access has game framework, which will allow you to c…”
   • [community] “I haven't used it, but I remember looking at the minified code a while back when it was first released. It looks very well done, by someone …”

   proof ↗⚑ flag

Rendering

1. game developerThe engine ships a modern production 3D renderer — PBR materials, global illumination or baked lighting, shadows, post-processing

   weight 3 · round to three.js
   three.js~partialcommunity4/10

   Evidence confirms a modern rendering pipeline (WebGLRenderer/WebGPURenderer, antialiasing, and node-based 'MeshStandardNodeMaterial' implying PBR-style materials) but the pack contains no explicit documentation of shadow mapping, global illumination/baked lighting, or a post-processing pipeline — a community comment even asks uncertainly whether lightmaps are possible. missing for 10: explicit shadow-mapping docs, GI/lightmap baking evidence, post-processing/effects pipeline documentation, independent confirmation of PBR material fidelity.

   • [claimed-docs] “When using TSL, use node-based materials: - MeshBasicNodeMaterial - MeshStandardNodeMaterial”
   • [claimed-docs] “Use WebGPURenderer when you need: - Custom shaders/materials using TSL (Three.js Shading Language) - Compute shaders - Advanced node-based m…”
   • [github] “const renderer = new THREE.WebGLRenderer( { antialias: true } ); renderer.setSize( width, height );”
   • [community] “That is called aliasing. Three.js defaults to it, but you can turn antialiasing on by passing the option to the WebGLRenderer.”
   • [community] “Can you actually generate lightmaps with three.js? I did a lot with it years ago. Really nice abstraction library.”

   proof ↗⚑ flag

   PlayCanvas—none0/10

   The evidence pack documents scripting, editor collaboration, physics, MCP integration, and Gaussian splatting support, but contains no first-party or community evidence about PBR materials, global illumination/baked lighting, shadow systems, or a post-processing pipeline. Per the rules, absence of evidence for this applicable rendering-feature axis must be scored as 'none' rather than inferred from outside knowledge.

   ⚑ flag

Collaboration

1. studio leadThe project format and tooling play well with version control and multi-person teams — mergeable scenes, diffable text formats, or built-in collaboration

   weight 2 · round to PlayCanvas
   three.js—none0/10

   three.js is a rendering library/API, not a scene-authoring tool with a project file format; evidence shows only a code-based API, an optional visual editor, and no mention of diffable scene formats, merge tooling, or multi-user collaboration features. This axis applies to engines/authoring tools generally, but nothing in the evidence indicates three.js ships mergeable/diffable project files or built-in collaboration.

   • [claimed-docs] “three.js editor”
   • [github] “This code creates a scene, a camera, and a geometric cube, and it adds the cube to the scene. It then creates a `WebGL` renderer for the sce…”
   • [claimed-docs] “[docs](manual/#en/creating-a-scene) [examples](examples/#webgl_animation_keyframes)”

   proof ↗⚑ flag

   PlayCanvas!disputedcontradicted4/10

   PlayCanvas markets real-time multi-user editing as solving merge conflicts entirely (docs-4, docs-13) rather than a diffable/VCS-friendly text format, but hands-on community reports concretely contradict the 'plays well with version control' framing: developers note the project lives on PlayCanvas's servers with 'no easy local dev environment' and that basics like 'using your own source control' are missing, with unofficial third-party tools (playcanvas-sync) needed just to sync assets locally, and uploading being a 'deal breaker' for offline/local workflows. Checkpoints (docs-5) offer some rollback safety but are not the same as git-based diff/merge tooling. missing for 10: official git-friendly/text-diffable scene format, first-party local-file sync equivalent to real VCS integration, and evidence the community-reported local-dev gap has been resolved.

   • [claimed-docs] “Multiple developers, artists, and designers can build the same scene simultaneously—no merge conflicts, no stepping on each other's toes.”
   • [claimed-docs] “With live editing, you can tweak materials, adjust positions, and even modify scripts while your application runs.”
   • [claimed-docs] “Checkpoints — Snapshot your project at any point and roll back if needed”
   • [community] “I think Playcanvas would do well to focus on the basics, like being able to export/import variables in the standard js way, being able to de…”
   • [community] “When I was working at a mobile game studio, we looked at this as an engine for a project. At the time we decided not to go with it since all…”
   • [community] “I think the engine is open source; but the real appeal is using the real time collab online tool, which is proprietary and had the drawbacks…”
   • [community] “I'd love to be able to use their scene editor offline, uploading assets is a deal breaker.”
   • [community] “I recommend checking out the newly released playcanvas-sync tools which let you map your PlayCanvas project's assets to your local machine's…”

   proof ↗⚑ flag

Editor

1. technical artistA full visual editor — viewport, inspector, prefabs/scene composition — is the primary way to build levels

   weight 3 · round to PlayCanvas
   three.js~partialclaimed3/10

   three.js ships a browser-based editor (threejs.org/editor) and devtools/TransformControls, but evidence only names the editor's existence with no documentation of an inspector, prefab system, or scene-composition workflow, and the library's primary workflow is code-first (constructing scenes via API) rather than a visual editor. Missing for 10: documented inspector UI, prefab/asset composition workflow, evidence the editor is treated as the primary level-building tool rather than a supplementary demo tool.

   • [claimed-docs] “three.js editor”
   • [claimed-docs] “[OrbitControls](https://threejs.org/docs/#examples/en/controls/OrbitControls) - [TransformControls](https://threejs.org/docs/#examples/en/co…”
   • [claimed-docs] “[devtools](https://chromewebstore.google.com/detail/threejs-devtools/jechbjkglifdaldbdbigibihfaclnkbo)”

   proof ↗⚑ flag

   PlayCanvas~partialcommunity6/10

   Docs confirm a full drag-and-drop visual Editor with real-time collaborative scene building, live editing of materials/positions, and checkpoint/versioning (playcanvas-docs-3, docs-4, docs-5, docs-13), which matches the viewport+scene-composition part of the story. However, no evidence explicitly documents an 'inspector' panel or a 'prefab' system by name, and community reports flag real dev-experience friction (no easy local dev, assets must be uploaded, offline editing not supported) that complicate treating the editor as the primary, frictionless build workflow. missing for 10: explicit inspector/prefab terminology and documentation, independent hands-on confirmation of prefab workflow, resolution of community-reported offline/local-dev friction.

   • [claimed-docs] “Want drag-and-drop scene building, real-time collaboration, or prefer visual tools over code”
   • [claimed-docs] “Multiple developers, artists, and designers can build the same scene simultaneously—no merge conflicts, no stepping on each other's toes.”
   • [claimed-docs] “Checkpoints — Snapshot your project at any point and roll back if needed”
   • [claimed-docs] “With live editing, you can tweak materials, adjust positions, and even modify scripts while your application runs.”
   • [community] “When I was working at a mobile game studio, we looked at this as an engine for a project. At the time we decided not to go with it since all…”
   • [community] “I'd love to be able to use their scene editor offline, uploading assets is a deal breaker.”

   proof ↗⚑ flag

Extensibility

1. game developerExtend and automate the editor itself — custom tools, editor scripts, plugins that manipulate scenes and assets programmatically

   weight 3 · round to PlayCanvas
   three.js—none0/10

   Evidence confirms three.js ships an editor (threejs.org/editor) and a devtools browser extension, but nothing in the pack describes any plugin API, scripting console, or extension mechanism for programmatically automating the editor itself — the docs excerpts focus on the library API (TSL, renderers, loaders, controls), not editor extensibility.

   • [claimed-docs] “three.js editor”
   • [claimed-docs] “[devtools](https://chromewebstore.google.com/detail/threejs-devtools/jechbjkglifdaldbdbigibihfaclnkbo)”

   proof ↗⚑ flag

   PlayCanvas✓fullprobed7/10

   PlayCanvas explicitly documents a scriptable Editor API module (api.playcanvas.com/editor) built 'for developers looking to... create custom editing tools, or integrate external data and systems into the PlayCanvas Editor environment,' plus an official MCP server for AI-driven automation of live Editor sessions, and community-built sync tools for local file mapping — together showing programmatic extension of the editor itself. Missing for 10: concrete example plugins/marketplace or hands-on demonstration of a third-party editor tool built with this API, and no independent review confirming ease of use for this specific API (only general dev-experience complaints exist).

   • [claimed-docs] “This module is essential for developers looking to streamline their workflow, create custom editing tools, or integrate external data and sy…”
   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”
   • [community] “I recommend checking out the newly released playcanvas-sync tools which let you map your PlayCanvas project's assets to your local machine's…”

   proof ↗⚑ flag

Ci

1. game developerBuild and export the project from the command line, headless, in CI — no human clicking an editor

   weight 3 · round to PlayCanvas
   three.js—none0/10

   Evidence shows three.js is a code-first WebGL/WebGPU library installed via npm/git and used with standard `WebGLRenderer` setup, but nothing documents a CLI or automated pipeline for building/exporting a 'project' headlessly in CI (no headless rendering support, no export tooling, no CI recipes) — the only editor mentioned (threejs.org/editor) is a browser GUI requiring human interaction. missing for 10: any documented headless rendering approach (e.g. headless-gl/Node canvas), a CLI build/export command, and CI pipeline examples.

   • [github] “const renderer = new THREE.WebGLRenderer( { antialias: true } ); renderer.setSize( width, height );”
   • [github] “git clone --depth=1 https://github.com/mrdoob/three.js.git”
   • [claimed-docs] “three.js editor”
   • [github] “This code creates a scene, a camera, and a geometric cube, and it adds the cube to the scene. It then creates a `WebGL` renderer for the sce…”

   proof ↗⚑ flag

   PlayCanvas~partialcommunity4/10

   The standalone Engine is a plain npm package usable with Vite/TypeScript scaffolding, so Engine-only projects can plausibly be built and bundled headlessly via a standard `vite build` in CI (playcanvas-gh-2, playcanvas-docs-1, playcanvas-docs-7). However, PlayCanvas's primary workflow is the cloud Editor, and community reports confirm no easy local dev environment or native CLI export — code/assets live on PlayCanvas's servers, requiring third-party 'playcanvas-sync' tooling and manual tinkering to approximate a local/CI workflow (playcanvas-comm-8, playcanvas-comm-9, playcanvas-comm-10). No first-party CLI/CI build-and-export tool for Editor projects is documented anywhere in the evidence. Missing for 10: an official CLI/CI export command for Editor-based projects, documentation of headless Editor project builds, and independent confirmation that Editor-based CI pipelines work reliably.

   • [github] “npm install playcanvas”
   • [claimed-docs] “Use `create-playcanvas` to scaffold a Vite and TypeScript project for the Engine, React, or Web Components from one of 12 runnable starters.”
   • [claimed-docs] “Build applications against the Engine directly. Learn how to use the Engine standalone.”
   • [community] “When I was working at a mobile game studio, we looked at this as an engine for a project. At the time we decided not to go with it since all…”
   • [community] “It's certainly not super obvious to setup but there are ways to use PlayCanvas with local setup... with some tinkering you can have hot modu…”
   • [community] “I recommend checking out the newly released playcanvas-sync tools which let you map your PlayCanvas project's assets to your local machine's…”

   proof ↗⚑ flag

Server

1. game developerGame logic runs headless on servers — a dedicated-server or server-runtime build without rendering

   weight 2 · round drawn
   three.js—none0/10

   three.js is fundamentally a browser-based WebGL/WebGPU rendering library requiring a canvas/GPU context; the evidence pack shows no headless/server-runtime build, no dedicated-server mode, and no mention of running game logic without rendering on Node.js servers. missing for 10: any headless rendering context (e.g. node-canvas/gl bindings), a documented server-runtime build, or dedicated-server examples.

   • [github] “The current builds only include WebGL and WebGPU renderers but SVG and CSS3D renderers are also available as addons.”
   • [probe] “PROBE runtime (recorded 2026-09-15): threejs.org publishes llms.txt at the site root pointing to a docs llms.txt that carries a literal '## …”

   proof ↗⚑ flag

   PlayCanvas—none0/10

   The evidence pack shows PlayCanvas as a browser-focused WebGL/WebGPU engine with npm packages, Editor, and MCP server tooling, but nothing about a dedicated headless/server-runtime build without rendering for running game logic on servers. Missing for 10: any docs or GitHub evidence of a headless Node.js server build, server-side simulation mode, or rendering-free runtime.

   • [claimed-docs] “Build applications against the Engine directly. Learn how to use the Engine standalone.”
   • [github] “npm install playcanvas”
   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”

   proof ↗⚑ flag

Testing

1. game developerTests run headlessly — unit and integration tests of game code execute in CI against the real engine

   weight 2 · round drawn
   three.js—none0/10

   No evidence in the pack addresses headless testing, CI integration, or running WebGLRenderer/WebGPURenderer without a browser context (e.g. via node-canvas, jsdom, or headless GL). All evidence covers rendering setup, docs, and community sentiment, none of it about automated/headless test execution.

   ⚑ flag

   PlayCanvas—none0/10

   No evidence of a testing framework, headless mode, or CI integration for running unit/integration tests against the PlayCanvas engine; docs cover scripting, editor, MCP server, and standalone engine usage but never mention headless test execution or CI workflows.

   ⚑ flag

Governance

1. studio leadThe project's governance and funding are transparent — a foundation, published finances, or a public roadmap I can plan against

   weight 1 · round drawn
   three.js—none0/10

   No evidence of a foundation, published finances, or public roadmap; three.js governance appears to be maintainer-driven (mrdoob) via GitHub releases/migration guides with no financial transparency artifacts in the pack.

   ⚑ flag

   PlayCanvas—none0/10

   No evidence of a governing foundation, published financials, or a public roadmap; PlayCanvas is run as a commercial product (subscription plans mentioned) with no transparency artifacts cited. Community comments discuss engine features and dev-experience, not governance or funding.

   ⚑ flag

License

1. studio leadThe license is permissive with no royalties or per-install fees — I keep what my game earns

   weight 3 · round to three.js
   three.js✓fullprobed9/10

   npm registry confirms three.js is MIT licensed, a permissive license with no royalties or per-install fees, verified directly from the package registry. Missing for 10: no explicit first-party licensing FAQ or legal statement addressing commercial game royalties specifically, relying instead on the generic MIT registry classification.

   • [probe] “PROBE runtime (recorded 2026-09-15): `npm view three version` → 0.186.0, and the public npm downloads API reports 12,206,532 weekly download…”

   proof ↗⚑ flag

   PlayCanvas✓fullprobed7/10

   The core PlayCanvas Engine is confirmed MIT-licensed and open source ('MIT engine runtime' in playcanvas-probe-rt-2; community confirms 'the engine is open source' in playcanvas-comm-11 and playcanvas-comm-16), meaning a studio can ship and monetize games without royalties or per-install fees on the runtime itself. However, evidence also shows the hosted Editor/collaboration tooling is a paid subscription (e.g., $15/month for private projects, playcanvas-comm-4), which is a studio-tooling cost rather than a revenue royalty, so it doesn't contradict the engine's permissive licensing but adds nuance. Missing for 10: explicit vendor documentation stating 'no royalties/no revenue share' policy and independent legal/community confirmation of unrestricted commercial use terms.

   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”
   • [community] “I think the engine is open source; but the real appeal is using the real time collab online tool, which is proprietary and had the drawbacks…”
   • [community] “It's an open source javascript game engine that is kinda like halfway between something like three.js and e.g. Unity—pretty lightweight, but…”
   • [community] “Every time I've taken a look at this engine it has always felt very limited. And with a $15/month subscription just to be able to create pri…”

   proof ↗⚑ flag

Source

1. game developerRead and modify the full engine source when I hit a wall

   weight 2 · round to three.js
   three.js✓fullprobed9/10

   three.js is open-source (MIT license per npm registry) with full source hosted on GitHub, clonable and directly modifiable, and community evidence confirms active engagement with the codebase (e.g., @ts-ignore workarounds, discussion of internals like antialiasing defaults). Missing for 10: no explicit first-party statement encouraging source modification as a supported workflow, and no case study of a game dev forking/patching the engine for a shipped title.

   • [probe] “PROBE runtime (recorded 2026-09-15): `npm view three version` → 0.186.0, and the public npm downloads API reports 12,206,532 weekly download…”
   • [github] “git clone --depth=1 https://github.com/mrdoob/three.js.git”
   • [community] “there are some function signatures that don't match what's in the code using @types/three, and mrdoob does not want to maintain this. This g…”
   • [community] “That is called aliasing. Three.js defaults to it, but you can turn antialiasing on by passing the option to the WebGLRenderer.”

   proof ↗⚑ flag

   PlayCanvas✓fullprobed8/10

   The PlayCanvas Engine is confirmed open source (MIT) and published on GitHub/npm, allowing developers to read and modify the core engine code directly, corroborated by community comment that 'the engine is open source' and runtime probes confirming the MIT license and public repo. Missing for 10: explicit contribution/build docs or a first-party statement of the license terms, and no independent hands-on account of someone actually patching engine internals.

   • [github] “Gaussian Splatting - First-class support for loading and rendering 3D Gaussian Splats”
   • [github] “npm install playcanvas”
   • [community] “I think the engine is open source; but the real appeal is using the real time collab online tool, which is proprietary and had the drawbacks…”
   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”

   proof ↗⚑ flag

Trust

1. studio leadThe pricing and license terms have a track record of stability — no retroactive changes that reprice games already shipped

   weight 2 · round to three.js
   three.js~partialprobed5/10

   three.js is MIT-licensed, verified from the npm registry, which is a free, permissive open-source license with no pricing terms to retroactively change — this structurally supports licensing stability. However, there is no explicit evidence pack documentation of license history, versioning of terms, or any studio commentary confirming a track record of stability over time. Missing for 10: explicit license-history documentation, third-party confirmation of no relicensing/repricing events, and studio-lead testimonials on licensing trust.

   • [probe] “PROBE runtime (recorded 2026-09-15): `npm view three version` → 0.186.0, and the public npm downloads API reports 12,206,532 weekly download…”

   proof ↗⚑ flag

   PlayCanvas—none0/10

   No evidence in the pack addresses pricing/licensing history, terms stability, or retroactive repricing of shipped games; only a $15/month subscription mention and a link to the plans page appear, with no discussion of contract stability or track record.

   ⚑ flag

1. ai-native userDo everything through the API that I can do in the UI

   weight 2 · round to PlayCanvas
   three.js—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

   PlayCanvas~partialprobed6/10

   PlayCanvas exposes a scriptable Editor API (api.playcanvas.com/editor) for custom editing tools and integrations, plus an official MCP server that lets AI assistants modify project data and verify results via the viewport — going beyond a typical 'no API' game engine. However there is no discoverable REST/OpenAPI spec (404s across probed endpoints), and no documentation explicitly claims full UI-API parity; some Editor-only features (drag-and-drop scene building, real-time collaboration) are framed as UI-first conveniences without confirmed programmatic equivalents. missing for 10: an explicit parity statement/spec covering all UI actions, a formal REST/OpenAPI contract, and independent confirmation that collaborative/visual editor features are fully scriptable.

   • [claimed-docs] “The PlayCanvas Editor MCP Server connects AI assistants to an open PlayCanvas Editor session. It can modify project data and verify the resu…”
   • [claimed-docs] “This module is essential for developers looking to streamline their workflow, create custom editing tools, or integrate external data and sy…”
   • [probe] “official MCP server documented at https://developer.playcanvas.com/user-manual/editor/mcp-server/”
   • [probe] “PROBE runtime (recorded 2026-09-15): PlayCanvas ships the only OFFICIAL, open, npm-published editor MCP server of the eight engines — `npm v…”
   • [probe] “PROBE openapi: all candidate paths 404 (https://developer.playcanvas.com/openapi.json, https://developer.playcanvas.com/swagger.json, https:…”
   • [claimed-docs] “Want drag-and-drop scene building, real-time collaboration, or prefer visual tools over code”

   proof ↗⚑ flag

2. ai-native userExport all of my data in open formats and leave

   weight 3 · round to PlayCanvas
   three.js—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

   PlayCanvas~partialcommunity5/10

   The engine itself is open-source (MIT, npm-published) and PlayCanvas offers 'Download Apps for Self-hosting', plus community tooling (playcanvas-sync) to map project assets to a local filesystem, giving users a path to exit the platform with their code/engine. However, there is no first-party documentation of a comprehensive 'export all project data in open formats' feature, and community reports explicitly flag that code/collaboration data lives on PlayCanvas's servers with no easy local dev environment, undercutting a full data-portability story. Missing for 10: an official bulk data-export tool/format for scenes, assets and editor project state, and independent confirmation that exported data is fully open and complete.

   • [claimed-docs] “Download Apps for Self-hosting”
   • [community] “When I was working at a mobile game studio, we looked at this as an engine for a project. At the time we decided not to go with it since all…”
   • [community] “It's certainly not super obvious to setup but there are ways to use PlayCanvas with local setup... with some tinkering you can have hot modu…”
   • [community] “I recommend checking out the newly released playcanvas-sync tools which let you map your PlayCanvas project's assets to your local machine's…”
   • [community] “I think the engine is open source; but the real appeal is using the real time collab online tool, which is proprietary and had the drawbacks…”
   • [github] “npm install playcanvas”

   proof ↗⚑ flag

3. ai-native userRead the product's source under an open license

   weight 2 · round drawn
   three.js✓fullprobed9/10

   three.js source is hosted publicly on GitHub (mrdoob/three.js) and distributed via npm under the MIT license, verified directly from the npm registry; the repo is clonable and openly browsable. missing for 10: no explicit license file text quoted in the evidence pack, only registry-confirmed MIT license metadata.

   • [github] “const renderer = new THREE.WebGLRenderer( { antialias: true } ); renderer.setSize( width, height );”
   • [github] “git clone --depth=1 https://github.com/mrdoob/three.js.git”
   • [probe] “PROBE runtime (recorded 2026-09-15): `npm view three version` → 0.186.0, and the public npm downloads API reports 12,206,532 weekly download…”

   proof ↗⚑ flag

   PlayCanvas✓fullprobed9/10

   PlayCanvas Engine is confirmed open source (GitHub repo, MIT license, npm-published), and community commentary independently corroborates 'the engine is open source' (playcanvas-comm-11, comm-16). The full engine source is browsable on GitHub and versioned, satisfying an AI-native user's ability to read source under an open license; missing for 10: explicit license file text/OSI confirmation cited directly in evidence.

   • [github] “Gaussian Splatting - First-class support for loading and rendering 3D Gaussian Splats”
   • [github] “npm install playcanvas”
   • [community] “I think the engine is open source; but the real appeal is using the real time collab online tool, which is proprietary and had the drawbacks…”
   • [community] “It's an open source javascript game engine that is kinda like halfway between something like three.js and e.g. Unity—pretty lightweight, but…”
   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”

   proof ↗⚑ flag

4. ai-native userSelf-host the core product

   weight 3 · round to three.js
   three.js✓fullprobed9/10

   three.js is an open-source (MIT) client-side library distributed via npm/GitHub that can be cloned, built, and self-hosted entirely without any vendor service, as shown by the git clone instructions and npm registry data. missing for 10: no explicit first-party 'self-hosting guide' doc beyond generic clone/build instructions, and no independent case study of a fully self-hosted deployment.

   • [github] “git clone --depth=1 https://github.com/mrdoob/three.js.git”
   • [probe] “PROBE runtime (recorded 2026-09-15): `npm view three version` → 0.186.0, and the public npm downloads API reports 12,206,532 weekly download…”
   • [github] “The current builds only include WebGL and WebGPU renderers but SVG and CSS3D renderers are also available as addons.”

   proof ↗⚑ flag

   PlayCanvas!disputedcontradicted5/10

   The core Engine is open-source (MIT, npm-published) and documented for standalone/self-hosted use (playcanvas-docs-7, playcanvas-gh-2), but the actual PlayCanvas product most users mean—the Editor/collaboration platform—is proprietary SaaS with no self-hosting option; community reports confirm project code must live on PlayCanvas's servers with no easy local dev environment (playcanvas-comm-8, playcanvas-comm-11, playcanvas-comm-12). The 'Download Apps for Self-hosting' doc refers to exporting built apps, not self-hosting the Editor itself. Missing for 10: an official self-hostable Editor/backend, first-party self-host deployment docs for the full platform, and resolution of the community-confirmed server-lock-in for authoring.

   • [claimed-docs] “Build applications against the Engine directly. Learn how to use the Engine standalone.”
   • [github] “npm install playcanvas”
   • [claimed-docs] “Download Apps for Self-hosting”
   • [community] “When I was working at a mobile game studio, we looked at this as an engine for a project. At the time we decided not to go with it since all…”
   • [community] “I think the engine is open source; but the real appeal is using the real time collab online tool, which is proprietary and had the drawbacks…”
   • [community] “I'd love to be able to use their scene editor offline, uploading assets is a deal breaker.”

   proof ↗⚑ flag

Targets

1. studio leadOne project exports to desktop, mobile, and (directly or via partners) consoles

   weight 3 · round drawn
   three.js—none0/10

   The evidence pack shows three.js is a browser-based WebGL/WebGPU rendering library with no documentation of a build/export pipeline to native desktop, mobile, or console targets — no mention of Electron/Cordova wrapping, console SDK partnerships, or platform-specific packaging tools. While the axis is fair to ask of any 3D technology a studio might adopt, there is no evidence three.js provides or facilitates such multi-platform export beyond running inside a web browser.

   • [github] “const renderer = new THREE.WebGLRenderer( { antialias: true } ); renderer.setSize( width, height );”
   • [github] “The current builds only include WebGL and WebGPU renderers but SVG and CSS3D renderers are also available as addons.”
   • [probe] “PROBE llms.txt: HTTP 200 at https://threejs.org/llms.txt # Three.js > Three.js is a cross-browser JavaScript library for creating 3D graphi…”

   proof ↗⚑ flag

   PlayCanvas—none0/10

   Evidence shows PlayCanvas engine and Editor covering web, desktop-via-browser, and self-hosted app export, but there is no mention anywhere in the pack of console export (PlayStation/Xbox/Switch) or partner porting programs. Community commentary consistently frames PlayCanvas as a web-first/WebGL engine with no console story. missing for 10: any documentation of console export or third-party console porting partnership, evidence of desktop/mobile packaging beyond generic 'download apps', console SDK support.

   • [claimed-docs] “Download Apps for Self-hosting”
   • [community] “It is a very nice engine, specially for those focused on Web only as target.”
   • [community] “It's an open source javascript game engine that is kinda like halfway between something like three.js and e.g. Unity—pretty lightweight, but…”

   proof ↗⚑ flag

Web

1. web developerMy game runs in the browser with a reasonable payload — WebGL today, and a credible WebGPU story

   weight 2 · round drawn
   three.js✓fullprobed8/10

   three.js runs in-browser via WebGLRenderer (widely used, huge npm install base) and has a credible, actively developed WebGPU story through WebGPURenderer plus TSL shaders that target both WebGL and WebGPU backends, with SVG/CSS3D as lighter addons keeping core payload lean. Community confirms it's a solid abstraction over WebGL, though payload/performance specifics for WebGPU maturity aren't independently benchmarked in evidence. missing for 10: independent bundle-size/payload benchmarks, and hands-on confirmation of WebGPU production readiness beyond docs claims.

   • [github] “const renderer = new THREE.WebGLRenderer( { antialias: true } ); renderer.setSize( width, height );”
   • [github] “The current builds only include WebGL and WebGPU renderers but SVG and CSS3D renderers are also available as addons.”
   • [claimed-docs] “**Use WebGPURenderer** when you need: - Custom shaders/materials using TSL (Three.js Shading Language) - Compute shaders - Advanced node-bas…”
   • [claimed-docs] “TSL benefits: - Works with both WebGL and WebGPU backends - No string manipulation or onBeforeCompile hacks”
   • [community] “Three.js is insane, in a good way. Great abstraction of WebGL, very user friendly, and surprisingly few things that it can't do, as long as …”
   • [community] “THREE.js adds a nice layer of abstraction atop that metal [WebGL].”
   • [probe] “PROBE runtime (recorded 2026-09-15): `npm view three version` → 0.186.0, and the public npm downloads API reports 12,206,532 weekly download…”

   proof ↗⚑ flag

   PlayCanvas✓fullprobed8/10

   PlayCanvas is explicitly documented as a WebGL/WebGPU engine (probe-1) with a lightweight open-source runtime (npm playcanvas package, MIT license) and community corroboration that it's well-suited to lean web deployment (comm-1, comm-6, comm-13, comm-16) versus bloated alternatives. Missing for 10: no explicit payload-size benchmarks or bundle-size comparisons, and no independent hands-on confirmation of WebGPU parity/performance versus WebGL in production games.

   • [probe] “PROBE llms.txt: HTTP 200 at https://developer.playcanvas.com/llms.txt # PlayCanvas Developer Documentation > PlayCanvas is an open-source W…”
   • [github] “npm install playcanvas”
   • [community] “Unreal is a bloated way to develop WebGPU projects for the web. PlayCanvas is a sensible solution if your target is web.”
   • [community] “It is a very nice engine, specially for those focused on Web only as target.”
   • [community] “THREE.js is very low-level framework, while PlayCanvas additionally to low-level engine access has game framework, which will allow you to c…”
   • [community] “It's an open source javascript game engine that is kinda like halfway between something like three.js and e.g. Unity—pretty lightweight, but…”
   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”

   proof ↗⚑ flag

2. web developerThe engine installs from a package registry into my existing toolchain — a library I import, bundle, and tree-shake like any dependency

   weight 2 · round to three.js
   three.js✓fullprobed9/10

   three.js is published on npm (12M+ weekly downloads, MIT license per registry probe) and is widely used as an ES module import (importmap pattern shown in docs), consistent with standard bundler/tree-shaking workflows; community feedback confirms TypeScript compatibility and typical dependency usage patterns. Missing for 10: no explicit first-party documentation or evidence specifically confirming tree-shaking behavior/bundle-size optimization guidance.

   • [probe] “PROBE runtime (recorded 2026-09-15): `npm view three version` → 0.186.0, and the public npm downloads API reports 12,206,532 weekly download…”
   • [claimed-docs] “CORRECT - modern pattern (always use latest version): html <script type="importmap">”
   • [community] “Btw three.js works flawlessly with Typescript too in case anyone is interested.”
   • [community] “there are some function signatures that don't match what's in the code using @types/three, and mrdoob does not want to maintain this. This g…”
   • [community] “THREE.js adds a nice layer of abstraction atop that metal [WebGL].”

   proof ↗⚑ flag

   PlayCanvas✓fullprobed8/10

   PlayCanvas engine is published to npm (`npm install playcanvas`, version 2.22.2, ~48k weekly downloads) as a standard ES module library, with docs on using the Engine standalone and scaffolding via create-playcanvas/Vite for standard bundler-based toolchains. Community confirms it integrates with other JS frameworks and modern web-dev workflows (HMR, bundlers), supporting tree-shakable ESM usage. Missing for 10: no explicit documentation or independent confirmation of tree-shaking behavior/bundle-size optimization guidance, and some community reports note setup isn't always straightforward.

   • [github] “npm install playcanvas”
   • [claimed-docs] “Build applications against the Engine directly. Learn how to use the Engine standalone.”
   • [claimed-docs] “Use `create-playcanvas` to scaffold a Vite and TypeScript project for the Engine, React, or Web Components from one of 12 runnable starters.”
   • [probe] “PROBE runtime (recorded 2026-09-15): developer.playcanvas.com serves llms.txt plus the largest llms-full.txt of the arena (2,053,637 bytes o…”
   • [community] “You can use it in conjunction with pretty much any other JS framework available.”
   • [community] “It's certainly not super obvious to setup but there are ways to use PlayCanvas with local setup... with some tinkering you can have hot modu…”

   proof ↗⚑ flag

Iteration

1. game developerThe edit-run loop is fast — hot reload or near-instant preview after a script change

   weight 2 · round to PlayCanvas
   three.js—none0/10

   three.js is a rendering library, not a game engine or dev environment with a build/watch pipeline; no evidence in the pack of any hot-reload, live-reload, or fast edit-run tooling shipped by the project itself (only unrelated docs, editor mentions, and API references).

   ⚑ flag

   PlayCanvas~partialcommunity6/10

   Docs claim live editing lets you tweak materials, positions, and even modify scripts while the application is running, and community reports confirm hot-module-replacement style workflows are achievable with the local sync tooling — but multiple community sources note this setup is 'certainly not super obvious' and historically required 'tinkering,' with one report citing no easy local dev environment as a dealbreaker at the time. missing for 10: first-party benchmark or docs describing built-in near-instant reload latency, and confirmation the friction reported in community threads has been resolved.

   • [claimed-docs] “With live editing, you can tweak materials, adjust positions, and even modify scripts while your application runs.”
   • [community] “It's certainly not super obvious to setup but there are ways to use PlayCanvas with local setup... with some tinkering you can have hot modu…”
   • [community] “When I was working at a mobile game studio, we looked at this as an engine for a project. At the time we decided not to go with it since all…”
   • [community] “I recommend checking out the newly released playcanvas-sync tools which let you map your PlayCanvas project's assets to your local machine's…”

   proof ↗⚑ flag

Language

1. game developerThe primary scripting language is productive and fully exposes the engine API, with a debugger behind it

   weight 3 · round to three.js
   three.js✓fullcommunity7/10

   Three.js is a plain JavaScript/TypeScript library, so the 'scripting language' is JS itself, giving full, direct access to the entire engine API with no separate scripting sandbox or restricted binding layer (threejs-gh-1, threejs-gh-4). Debugging is supported via standard browser devtools plus a dedicated official Chrome three.js DevTools extension (threejs-docs-8), and TypeScript works well though community reports note occasional @types/three signature mismatches requiring ts-ignore (threejs-comm-4, threejs-comm-5). Missing for 10: deeper first-party documentation of the debugger extension's capabilities and stronger independent corroboration of TypeScript API completeness.

   • [github] “const renderer = new THREE.WebGLRenderer( { antialias: true } ); renderer.setSize( width, height );”
   • [github] “This code creates a scene, a camera, and a geometric cube, and it adds the cube to the scene. It then creates a `WebGL` renderer for the sce…”
   • [claimed-docs] “[devtools](https://chromewebstore.google.com/detail/threejs-devtools/jechbjkglifdaldbdbigibihfaclnkbo)”
   • [community] “Btw three.js works flawlessly with Typescript too in case anyone is interested.”
   • [community] “there are some function signatures that don't match what's in the code using @types/three, and mrdoob does not want to maintain this. This g…”

   proof ↗⚑ flag

   PlayCanvas~partialcommunity6/10

   PlayCanvas scripting uses standard JavaScript/TypeScript (ESM `.mjs` scripts with class syntax) and the full engine can be scripted via `npm install playcanvas`, giving broad API access and a productive, familiar language; community comments (e.g. comm-13) also praise its game-framework layer atop low-level access. However, the evidence pack never explicitly documents a debugger (e.g. browser devtools breakpoints, source maps, or an IDE debug workflow) tied to scripting, and some community feedback flags dev-experience friction (playcanvas-comm-2, playcanvas-comm-3, playcanvas-comm-9) around local/offline workflows that could affect debugging setup. Missing for 10: explicit documentation of a debugger/breakpoint workflow for scripts, and confirmation that the full engine API (not just scripting hooks) is exposed without gaps.

   • [claimed-docs] “ESM Scripts (`.mjs` files) — Modern ES Module-based scripts using class syntax. Recommended for new projects.”
   • [claimed-docs] “ESM Scripts (`.mjs` files) — Modern ES Module-based scripts using class syntax. **Recommended for new projects.**”
   • [claimed-docs] “Build applications against the Engine directly. Learn how to use the Engine standalone.”
   • [github] “npm install playcanvas”
   • [community] “THREE.js is very low-level framework, while PlayCanvas additionally to low-level engine access has game framework, which will allow you to c…”
   • [community] “It's certainly not super obvious to setup but there are ways to use PlayCanvas with local setup... with some tinkering you can have hot modu…”

   proof ↗⚑ flag

Visual

1. technical artistBuild gameplay logic with visual scripting without writing code

   weight 2 · round drawn
   three.js—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

   PlayCanvas—none0/10

   Evidence shows PlayCanvas scripting is code-based (ESM/.mjs JavaScript classes) and the Editor supports drag-and-drop scene building and collaboration, but there is no mention of a node-based or visual scripting system for gameplay logic comparable to Blueprints/Bolt that would let a technical artist avoid writing code.

   • [claimed-docs] “ESM Scripts (`.mjs` files) — Modern ES Module-based scripts using class syntax. Recommended for new projects.”
   • [claimed-docs] “Want drag-and-drop scene building, real-time collaboration, or prefer visual tools over code”
   • [claimed-docs] “ESM Scripts (`.mjs` files) — Modern ES Module-based scripts using class syntax. **Recommended for new projects.**”

   proof ↗⚑ flag