Function generateThumbnail

renderer.js:15613–15686

(file)

}

// NOTE: loadModel function is defined earlier in the file (around line 2840)
// This duplicate has been removed to use the enhanced version that checks for embedded images

function fitCameraToObject(camera, object, scene, renderer) {
  // Orient first, then measure — otherwise large flat STLs (e.g. 400×420×4 plates)
  // get framed for the wrong bbox and often land past the camera far plane.
  object.rotation.x = -Math.PI / 2;
  object.updateMatrixWorld(true);

  const boundingBox = new THREE.Box3().setFromObject(object);
  const size = boundingBox.getSize(new THREE.Vector3());
  const center = boundingBox.getCenter(new THREE.Vector3());

  if (Number.isFinite(center.x) && Number.isFinite(center.y) && Number.isFinite(center.z)) {
    object.position.sub(center);
    object.updateMatrixWorld(true);
  }

  const fittedBox = new THREE.Box3().setFromObject(object);
  const fittedSize = fittedBox.getSize(new THREE.Vector3());
  const maxDim = Math.max(fittedSize.x, fittedSize.y, fittedSize.z, 1e-3);

  const fov = camera.fov * (Math.PI / 180);
  const tanHalfFov = Math.tan(fov / 2);
  let cameraZ =
    maxDim > 0 && tanHalfFov > 0
      ? Math.abs(maxDim / 2 / tanHalfFov) * 1.5
      : 5;
  if (!Number.isFinite(cameraZ) || cameraZ <= 0) cameraZ = 5;

  // Camera sits on the (z,z,z) diagonal — keep far plane beyond that distance.
  const cameraDistance = cameraZ * Math.sqrt(3);
  camera.near = Math.max(0.01, cameraDistance / 1000);
  camera.far = Math.max(10000, cameraDistance * 20);
  camera.updateProjectionMatrix();

  camera.position.set(cameraZ, cameraZ, cameraZ);
  camera.lookAt(0, 0, 0);

  renderer.render(scene, camera);
}

/** True when a thumbnail data-URL is effectively empty (transparent / clipped render). */
function isMostlyEmptyThumbnailDataUrl(dataUrl) {
  return new Promise((resolve) => {
    if (!dataUrl || typeof dataUrl !== 'string' || !dataUrl.startsWith('data:image')) {
      resolve(true);
      return;
    }
    const img = new Image();
    img.onload = () => {
      try {
        const w = Math.min(64, img.width || 64);
        const h = Math.min(64, img.height || 64);
        const canvas = document.createElement('canvas');
        canvas.width = w;
        canvas.height = h;
        const ctx = canvas.getContext('2d', { willReadFrequently: true });