ARCore Cloud Anchor API は、ARCore の対応デバイスすべてで動作します。
Cloud Anchor の仕組み
ARCore は ARCore API クラウド エンドポイントに接続して Cloud Anchors をホストし、解決することで、これらの共有エクスペリエンスを可能にします。これには、インターネット接続が必要です。
ホスティングと解決の仕組みの概要は次のとおりです。
ユーザーが環境にローカル アンカーを作成します。
アンカーがホストされている - ARCore はローカル アンカーのデータを ARCore API クラウド エンドポイントにアップロードし、エンドポイントはそのアンカーの一意の ID を返します。
アプリはその一意の ID を他のユーザーに配布します。
アンカーが解決されている - デバイスに一意の ID があるユーザーは、ARCore Cloud Anchor API を使用して同じアンカーを再作成できます。
ホスティング
ARCore は、アンカーを確立してホストするために、そのアンカーの周囲の空間の 3D 特徴マップを使用します。この特徴マップを取得するには、ホスト呼び出しの前に、デバイスの背面カメラでさまざまな視点と位置から被写体の中心とその周囲の環境をマッピングする必要があります。ARCore Cloud Anchor API は、空間の 3D 特徴マップを作成し、一意の Cloud Anchor ID をデバイスに返します。
解決中
同じ環境内の別のユーザーが、Cloud Anchor がホストされている領域にデバイスのカメラを向けると、解決リクエストにより、ARCore Cloud Anchor API はシーンの視覚的特徴を作成された 3D 特徴マップと定期的に比較します。ARCore は、これらの比較を使用して、Cloud Anchor に対するユーザーの位置、向き、ポーズを特定します。
[[["わかりやすい","easyToUnderstand","thumb-up"],["問題の解決に役立った","solvedMyProblem","thumb-up"],["その他","otherUp","thumb-up"]],[["必要な情報がない","missingTheInformationINeed","thumb-down"],["複雑すぎる / 手順が多すぎる","tooComplicatedTooManySteps","thumb-down"],["最新ではない","outOfDate","thumb-down"],["翻訳に関する問題","translationIssue","thumb-down"],["サンプル / コードに問題がある","samplesCodeIssue","thumb-down"],["その他","otherDown","thumb-down"]],["最終更新日 2025-07-26 UTC。"],[[["\u003cp\u003eARCore enables AR experiences within Android Instant Apps, allowing users to engage without prior installation.\u003c/p\u003e\n"],["\u003cp\u003eUnlike regular apps, AR-enabled Instant Apps require explicit checks and installation prompts for Google Play Services for AR.\u003c/p\u003e\n"],["\u003cp\u003eDevelopers need to be mindful of the size constraints imposed on Instant Apps, with the ARCore SDK contributing to the limit.\u003c/p\u003e\n"],["\u003cp\u003eCreating an instant-enabled app bundle is the starting point for integrating ARCore with Instant Apps.\u003c/p\u003e\n"]]],[],null,["# Cloud Anchors allow different users to share AR experiences\n\n**Platform-specific guides** \n\n### Android (Kotlin/Java)\n\n- [Quickstart](/ar/develop/java/cloud-anchors/quickstart)\n- [Developer guide](/ar/develop/java/cloud-anchors/developer-guide)\n\n### Android NDK (C)\n\n- [Developer guide](/ar/develop/c/cloud-anchors/developer-guide)\n\n### Unity (AR Foundation)\n\n- [Developer guide](/ar/develop/unity-arf/cloud-anchors/developer-guide)\n\n### iOS\n\n- [Quickstart](/ar/develop/ios/cloud-anchors/quickstart)\n- [Developer guide](/ar/develop/ios/cloud-anchors/developer-guide)\n\n### Unreal Engine\n\n- [ARCore SDK for Unreal Engine (official documentation)](https://docs.unrealengine.com/5.0/en-US/developing-for-arcore-in-unreal-engine/)\n\nA **Cloud Anchor** is a special type of [anchor](/ar/develop/anchors) that can be used to persist AR experiences in the real world. With the **ARCore Cloud Anchor API** , or **ARCore Cloud Anchor service**, you can create interactive layers of digital information and anchor them to actual locations, designing experiences that can be shared over time by multiple people across many different devices. Cloud Anchors connect real world locations with digital content that anyone can access from compatible mobile devices. Both Android and iOS users can participate in the same experience and return to them again and again, even weeks or months later.\n\nAnchors and Cloud Anchors\n-------------------------\n\nCloud Anchors are anchors that are hosted on the [ARCore API](https://console.cloud.google.com/apis/library/arcore) cloud endpoint. This hosting enables users to share experiences in the same app. The basic guidelines for anchors also apply to Cloud Anchors.\n\nUse cases for developing with the ARCore Cloud Anchor API\n---------------------------------------------------------\n\nThe ARCore Cloud Anchor API can help persist AR experiences in the real world and create shared experiences between users. The following are some ways you can use it in your own projects.\n\n### Persist AR experiences in the real world\n\nCloud Anchors enable one user to place an AR object in the physical environment and another to see the same object at the same place at a later time. For example, use Cloud Anchors to create virtual signs in front of stores, leave virtual notes on their kitchen countertops for their friends, or redecorate their bedrooms with virtual posters. In general, Cloud Anchors are best used for room-scale AR experiences.\n\n### Real-time collaborative experiences\n\nCloud Anchors also enable real-time collaboration between users. For example, users can play a virtual game of ping-pong on the coffee table, or paint a virtual mural together with their community.\n\nDevice compatibility\n--------------------\n\nThe ARCore Cloud Anchor API works on all ARCore [supported devices](/ar/devices).\n\nHow Cloud Anchors work\n----------------------\n\nARCore connects to the [ARCore API](https://console.cloud.google.com/apis/library/arcore) cloud endpoint to host and resolve Cloud Anchors, thereby enabling these shared experiences. This requires a working Internet connection.\n\nHere's a high-level picture of how hosting and resolving works:\n\n1. The user creates a local anchor in their environment.\n2. The anchor is **hosted** --- ARCore uploads that local anchor's data to the ARCore API cloud endpoint, and the endpoint returns a unique ID for that anchor.\n3. The app distributes that unique ID to other users.\n4. The anchor is **resolved** --- Users whose devices have the unique ID can recreate the same anchor using the ARCore Cloud Anchor API.\n\n### Hosting\n\nYour browser does not support the video tag.\n\nTo establish and host an anchor, ARCore uses a 3D feature map of the space surrounding that anchor. To obtain this feature map, the device's rear camera must map the environment in and around the center of interest from different viewing angles and positions before the host call. The ARCore Cloud Anchor API then creates a 3D feature map of the space, and returns a unique Cloud Anchor ID to the device.\n\n### Resolving\n\nYour browser does not support the video tag.\n\nWhen another user in the same environment points their device's camera at the area where the Cloud Anchor was hosted, a resolve request causes the ARCore Cloud Anchor API to periodically compare visual features from the scene against the 3D feature map that was created. ARCore uses these comparisons to pinpoint the user's position, orientation, and pose relative to the Cloud Anchor.\n\n### API deprecation policy\n\nSee [ARCore Cloud Anchor API deprecation policy](/ar/develop/cloud-anchors/cloud-anchor-deprecation-policy)\nfor details."]]
