Overview

I tried out annotations in Sketchfab, so this is a personal note for future reference.

Ultimately, I created the following viewer.

https://nakamura196.github.io/SketchfabAnnotationViewer/

https://youtu.be/iEe6TbI3X70

Data Used

We will use the “Ishibuchi Family Globe” from the “Kikuchi City / Digital Archive.”

https://adeac.jp/kikuchi-city/catalog/e0001

Usage Example

First, I uploaded the 3D data to Sketchfab.

https://skfb.ly/pt8oU

Then I added annotations. As a result, the following page was prepared.

Using the API

Please also refer to the following repository.

https://github.com/nakamura196/SketchfabAnnotationViewer

With the following script, I was able to retrieve a list of annotations, specify the annotation to display initially, and focus on a selected annotation.

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Sketchfab Annotation Viewer</title>
    <script src="https://cdn.tailwindcss.com"></script>
  </head>
  <body class="bg-gray-100 font-sans">
    <!-- メインコンテナ -->
    <div class="max-w-4xl mx-auto py-10 px-4">
      <!-- ヘッダー -->
      <h1 class="text-2xl font-bold text-gray-800 text-center mb-6">
        Sketchfab Annotation Viewer
      </h1>

      <!-- 3Dビューア -->
      <div class="mb-6">
        <iframe
          id="api-frame"
          width="100%"
          height="480"
          class="rounded shadow-md border border-gray-300"
          src=""
          allowfullscreen
        ></iframe>
      </div>

      <!-- アノテーションリスト -->
      <h2 class="text-xl font-semibold text-gray-700 mb-4">Annotations</h2>
      <ul id="annotation-list" class="space-y-2">
        <!-- アノテーション項目はJavaScriptで追加 -->
      </ul>
    </div>

    <script src="https://static.sketchfab.com/api/sketchfab-viewer-1.12.1.js"></script>
    <script src="script.js"></script>
  </body>
</html>

// Sketchfab Viewerを埋め込むためのiframeを取得
const iframe = document.getElementById('api-frame');
const client = new Sketchfab(iframe);

const urlParams = new URLSearchParams(window.location.search);
// SketchfabモデルIDを指定
const modelId = urlParams.get('id') || '02add905e79c446994f971cbcf443815'; // 'id'パラメータを取得
const pos = parseInt(urlParams.get('pos'), 10) || 0;

// APIのオプションを指定してモデルをロード
client.init(modelId, {
    success: function (api) {
        api.start();
        api.addEventListener('viewerready', function () {
            setupAnnotations(api);

            focusAnnotation(api, pos); // 最初のアノテーションにフォーカス
        });
    },
    error: function () {
        console.error('Sketchfab Viewer failed to load');
    },
});

function setupAnnotations(api) {
    api.getAnnotationList(function (err, annotations) {

        if (err) {
            console.error('Failed to fetch annotations');
            return;
        }

        // アノテーション一覧をHTMLに追加
        const annotationListContainer = document.getElementById('annotation-list');
        annotations.forEach((annotation, index) => {
            const annotationItem = document.createElement('li');
            annotationItem.textContent = annotation.name; // アノテーションタイトル
            annotationItem.addEventListener('click', () => {
                focusAnnotation(api, index); // クリック時にフォーカス
            });
            annotationListContainer.appendChild(annotationItem);
        });

    });
}
function focusAnnotation(api, annotationIndex) {
    api.gotoAnnotation(annotationIndex, {
        preventCameraAnimation: false, // アニメーションを許可
    });
    // api.showAnnotation(annotationIndex); // アノテーションを表示
    // api.showAnnotationTooltip(annotationIndex); // アノテーションツールチップを表示
}

Summary

I hope this serves as a useful reference for applying annotations to 3D data.