<canvas id="c"></canvas>
<script async src="https://unpkg.com/es-module-shims@1.6.3/dist/es-module-shims.js"></script>

<script type="importmap">
    {
        "imports": {
            "three": "https://cdn.jsdelivr.net/npm/three@0.150.0/build/three.module.js",
            "addons/": "https://cdn.jsdelivr.net/npm/three@0.150.0/examples/jsm/"
        }
    }
</script>
html, body {
  margin: 0;
  height: 100%;
}
#c {
  width: 100%;
  height: 100%;
  display: block;
}
// Three.js - Load .GLTF
// from https://threejs.org/manual/examples/load-gltf.html


import * as THREE from 'three';
import {OrbitControls} from 'addons/controls/OrbitControls.js';
import {GLTFLoader} from 'addons/loaders/GLTFLoader.js';
import {TransformControls} from 'addons/controls/TransformControls.js';
let tControls

function main() {
  const canvas = document.querySelector('#c');
  const renderer = new THREE.WebGLRenderer({canvas});
  renderer.outputEncoding = THREE.sRGBEncoding;

  const fov = 45;
  const aspect = 2;  // the canvas default
  const near = 0.1;
  const far = 100;
  const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  camera.position.set(0, 10, 20);

  const controls = new OrbitControls(camera, canvas);
  controls.target.set(0, 5, 0);
  controls.update();

  const scene = new THREE.Scene();
  scene.background = new THREE.Color('black');

  {
    const planeSize = 40;

    const loader = new THREE.TextureLoader();
    const texture = loader.load('https://threejs.org/manual/examples/resources/images/checker.png');
    texture.wrapS = THREE.RepeatWrapping;
    texture.wrapT = THREE.RepeatWrapping;
    texture.magFilter = THREE.NearestFilter;
    const repeats = planeSize / 2;
    texture.repeat.set(repeats, repeats);

    const planeGeo = new THREE.PlaneGeometry(planeSize, planeSize);
    const planeMat = new THREE.MeshPhongMaterial({
      map: texture,
      side: THREE.DoubleSide,
    });
    const mesh = new THREE.Mesh(planeGeo, planeMat);
    mesh.rotation.x = Math.PI * -.5;
    scene.add(mesh);
  }

  {
    const skyColor = 0xB1E1FF;  // light blue
    const groundColor = 0xB97A20;  // brownish orange
    const intensity = 0.6;
    const light = new THREE.HemisphereLight(skyColor, groundColor, intensity);
    scene.add(light);
  }

  {
    const color = 0xFFFFFF;
    const intensity = 0.8;
    const light = new THREE.DirectionalLight(color, intensity);
    light.position.set(5, 10, 2);
    scene.add(light);
    scene.add(light.target);
  }

  function frameArea(sizeToFitOnScreen, boxSize, boxCenter, camera) {
    const halfSizeToFitOnScreen = sizeToFitOnScreen * 0.5;
    const halfFovY = THREE.MathUtils.degToRad(camera.fov * .5);
    const distance = halfSizeToFitOnScreen / Math.tan(halfFovY);
    // compute a unit vector that points in the direction the camera is now
    // in the xz plane from the center of the box
    const direction = (new THREE.Vector3())
        .subVectors(camera.position, boxCenter)
        .multiply(new THREE.Vector3(1, 0, 1))
        .normalize();

    // move the camera to a position distance units way from the center
    // in whatever direction the camera was from the center already
    camera.position.copy(direction.multiplyScalar(distance).add(boxCenter));

    // pick some near and far values for the frustum that
    // will contain the box.
    camera.near = boxSize / 100;
    camera.far = boxSize * 100;

    camera.updateProjectionMatrix();

    // point the camera to look at the center of the box
    camera.lookAt(boxCenter.x, boxCenter.y, boxCenter.z);
    

          
  }

  {
    const gltfLoader = new GLTFLoader();
    gltfLoader.load('https://3dpk.co.uk/models/flag1.glb', (gltf) => {
      const root = gltf.scene;
      scene.add(root);
    tControls = new TransformControls( camera, renderer.domElement )
      tControls.attach(root);
      scene.add(tControls)

      // compute the box that contains all the stuff
      // from root and below
      const box = new THREE.Box3().setFromObject(root);

      const boxSize = box.getSize(new THREE.Vector3()).length();
      const boxCenter = box.getCenter(new THREE.Vector3());
      root.children[0].position.y -= boxSize / 2 
      root.position.y += boxSize / 2 


      
      // let nextBH = new THREE.BoxHelper();
      // nextBH.material.color.set(0x00ff00)
      // nextBH.setFromObject(root)
      // scene.add(nextBH)

      // set the camera to frame the box
      frameArea(boxSize * 0.5, boxSize, boxCenter, camera);

      // update the Trackball controls to handle the new size
      controls.maxDistance = boxSize * 10;
      controls.target.copy(boxCenter);
      controls.update();
    });
  }

  function resizeRendererToDisplaySize(renderer) {
    const canvas = renderer.domElement;
    const width = canvas.clientWidth;
    const height = canvas.clientHeight;
    const needResize = canvas.width !== width || canvas.height !== height;
    if (needResize) {
      renderer.setSize(width, height, false);
    }
    return needResize;
  }

  function render() {
    if (resizeRendererToDisplaySize(renderer)) {
      const canvas = renderer.domElement;
      camera.aspect = canvas.clientWidth / canvas.clientHeight;
      camera.updateProjectionMatrix();
    }

    renderer.render(scene, camera);

    requestAnimationFrame(render);
  }

 render();
}

main();
Run Pen

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.