I want to produce an effect using JavaScript/ jQuery such that a user can drag an object and rotate it. how can I do it? are there any predefined libraries, scripts, etc. any help is appreciated. example: thymia.world/ I'm also attaching snaps for a brief demo.
Initial View
After dragging view
three.js is a JavaScript library for 3D animation. Here is an example of someone rotating a mesh when the user drags the mouse. The key line of code is when it creates a Quaterion rotation from the equivalent Euler angles which is a very natural way to describe a rotation. By making the angle of rotation about the x-axis and y-axis proportional to the distance the mouse dragged a very natural interface is achieved.
Source code:
var three = THREE;
var scene = new three.Scene();
var camera = new three.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);
var renderer = new three.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
var geometry = new three.BoxGeometry(1, 1, 1);
//var material = new three.MeshNormalMaterial();
/* * /
var material = new three.MeshBasicMaterial({
color: 0x00ff00
});
/* */
/* */
three.ImageUtils.crossOrigin = '';
var texture = three.ImageUtils.loadTexture('http://i.imgur.com/CEGihbB.gif');
texture.anisotropy = renderer.getMaxAnisotropy();
var material = new three.MeshFaceMaterial([
new three.MeshBasicMaterial({
color: 0x00ff00
}),
new three.MeshBasicMaterial({
color: 0xff0000
}),
new three.MeshBasicMaterial({
//color: 0x0000ff,
map: texture
}),
new three.MeshBasicMaterial({
color: 0xffff00
}),
new three.MeshBasicMaterial({
color: 0x00ffff
}),
new three.MeshBasicMaterial({
color: 0xff00ff
})
]);
/* */
var cube = new three.Mesh(geometry, material);
cube.rotation.x = Math.PI/4;
cube.rotation.y = Math.PI/4;
scene.add(cube);
camera.position.z = 5;
/* */
var isDragging = false;
var previousMousePosition = {
x: 0,
y: 0
};
$(renderer.domElement).on('mousedown', function(e) {
isDragging = true;
})
.on('mousemove', function(e) {
//console.log(e);
var deltaMove = {
x: e.offsetX-previousMousePosition.x,
y: e.offsetY-previousMousePosition.y
};
if(isDragging) {
var deltaRotationQuaternion = new three.Quaternion()
.setFromEuler(new three.Euler(
toRadians(deltaMove.y * 1),
toRadians(deltaMove.x * 1),
0,
'XYZ'
));
cube.quaternion.multiplyQuaternions(deltaRotationQuaternion, cube.quaternion);
}
previousMousePosition = {
x: e.offsetX,
y: e.offsetY
};
});
/* */
$(document).on('mouseup', function(e) {
isDragging = false;
});
// shim layer with setTimeout fallback
window.requestAnimFrame = (function(){
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
function(callback) {
window.setTimeout(callback, 1000 / 60);
};
})();
var lastFrameTime = new Date().getTime() / 1000;
var totalGameTime = 0;
function update(dt, t) {
//console.log(dt, t);
//camera.position.z += 1 * dt;
//cube.rotation.x += 1 * dt;
//cube.rotation.y += 1 * dt;
setTimeout(function() {
var currTime = new Date().getTime() / 1000;
var dt = currTime - (lastFrameTime || currTime);
totalGameTime += dt;
update(dt, totalGameTime);
lastFrameTime = currTime;
}, 0);
}
function render() {
renderer.render(scene, camera);
requestAnimFrame(render);
}
render();
update(0, totalGameTime);
function toRadians(angle) {
return angle * (Math.PI / 180);
}
function toDegrees(angle) {
return angle * (180 / Math.PI);
}
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