boundingSphere

const tileset = await Cesium3DTileset.fromUrl("http://localhost:8002/tilesets/Seattle/tileset.json");

viewer.scene.primitives.add(tileset);

// Set the camera to view the newly added tileset
viewer.camera.viewBoundingSphere(tileset.boundingSphere, new HeadingPitchRange(0, -0.5, 0));