THREE.js Image aspect ratio

Question

I am having trouble figuring out how to set a PlaneGeometry to a good aspect ratio based on the image size.

var material = new THREE.MeshBasicMaterial({
        map : THREE.ImageUtils.loadTexture('img/bunny.png')
});
var plane = new THREE.Mesh(new THREE.PlaneGeometry(20, 20*.75), material);
plane.position.set(0, 10, -60)
scene.add(plane);

What I've tried so far sort of works, but I realise I'm still setting a fixed width/height on the Plane.

I'd like the plane to set the size of the image, then I could scale it down.

Answer 1

var planeGeom = new THREE.PlaneGeometry(20, 20);
var imgSrc = "https://upload.wikimedia.org/wikipedia/commons/5/5f/BBB-Bunny.png"
var mesh;
var tex = new THREE.TextureLoader().load(imgSrc, (tex) => {
  tex.needsUpdate = true;
  mesh.scale.set(1.0, tex.image.height / tex.image.width, 1.0);
});

var material = new THREE.MeshLambertMaterial({
  color: 0xffffff,
  map: tex
});
mesh = new THREE.Mesh(planeGeom, material);
scene.add(mesh);

//Working snippet is below...

var renderer = new THREE.WebGLRenderer();
var w = 300;
var h = 200;
renderer.setSize(w, h);
document.body.appendChild(renderer.domElement);

var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(
  45, // Field of view
  w / h, // Aspect ratio
  0.1, // Near
  10000 // Far
);
camera.position.set(15, 10, 15);
camera.lookAt(scene.position);
controls = new THREE.OrbitControls(camera, renderer.domElement);

var light = new THREE.PointLight(0xFFFFFF);
light.position.set(20, 20, 20);
scene.add(light);
var light1 = new THREE.AmbientLight(0x808080);
light1.position.set(20, 20, 20);
scene.add(light1);

var planeGeom = new THREE.PlaneGeometry(20, 20);
var imgSrc = "https://upload.wikimedia.org/wikipedia/commons/5/5f/BBB-Bunny.png"
var mesh;
var tex = new THREE.TextureLoader().load(imgSrc, (tex) => {
  tex.needsUpdate = true;
  mesh.scale.set(1.0, tex.image.height / tex.image.width, 1.0);
});

var material = new THREE.MeshLambertMaterial({
  color: 0xffffff,
  map: tex
});
mesh = new THREE.Mesh(planeGeom, material);
scene.add(mesh);
renderer.setClearColor(0xdddddd, 1);


(function animate() {
  requestAnimationFrame(animate);
  controls.update();
  renderer.render(scene, camera);
})();

<script src="https://threejs.org/build/three.min.js"></script>
<script src="https://cdn.rawgit.com/mrdoob/three.js/master/examples/js/controls/OrbitControls.js"></script>