I am currently working on the example provided in Chapter 2 of the WebGL Up and Running book.
My goal is to display a static texture-mapped cube.
The initial code snippet is not functioning as expected:
var camera = null,
renderer = null,
scene = null,
cube = null,
animating = false;
function onLoad() {
// Grab our container div
var container = document.getElementById("container");
// Create the Three.js renderer, add it to our div
renderer = new THREE.WebGLRenderer({
antialias: true
});
renderer.setSize(container.offsetWidth, container.offsetHeight);
container.appendChild(renderer.domElement);
// Create a new Three.js scene
scene = new THREE.Scene();
// Put in a camera
camera = new THREE.PerspectiveCamera(45,
container.offsetWidth / container.offsetHeight, 1, 4000);
camera.position.set(0, 0, 3);
// Create a directional light to show off the object
var light = new THREE.DirectionalLight(0xffffff, 1.5);
light.position.set(0, 0, 1);
scene.add(light);
// Create a shaded, texture-mapped cube and add it to the scene
// First, create the texture map
var mapUrl = "cuttherope.jpg";
var map = THREE.ImageUtils.loadTexture(mapUrl);
// Now, create a Phong material to show shading; pass in the map
var material = new THREE.MeshPhongMaterial({
map: map
});
// Create the cube geometry
var geometry = new THREE.CubeGeometry(1, 1, 1);
// And put the geometry and material together into a mesh
cube = new THREE.Mesh(geometry, material);
// Turn it toward the scene, or we won't see the cube shape!
cube.rotation.x = Math.PI / 5;
cube.rotation.y = Math.PI / 5;
// Add the cube to our scene
scene.add(cube);
renderer.render(scene, camera);
}
Once I added a run function and incorporated requestAnimationFrame, the cube appeared successfully.
...
cube.rotation.x = Math.PI / 5;
cube.rotation.y = Math.PI / 5;
// Add the cube to our scene
scene.add(cube);
run();
}
function run() {
renderer.render(scene, camera);
requestAnimationFrame(run);
}
If anyone could explain why this modification was necessary, I would greatly appreciate it! Thank you!