許多購物網站現在都支援360實體全景影像，可以360度任意選擇查看樣品，這樣對購買者來說是一個很好的消費體驗，網路上有很多這樣的插件都是基於jQuery實現的有收費的也有免費的，其實很好用的一個叫3deye.js的插件。該外掛支援桌面與行動終端iOS與Android，它的demo程式：http://www.voidcanvas.com/demo/28823deye/
自己玩了玩這個Demo以後，照著它的思路，用HTML5 Canvas也實現了類似的功能。
所以先說一下它的360度全景圖的原理1. 首先需要對實體拍照，間隔是每張照片旋轉15度，所以需要23張照片。
2.照片準備好了以後，盡量選擇JPG格式，裁切到適當大小。
3.JavaScript中預先載入所有照片，可以配合進度條顯示載入精度
4.建立/取得Canvas對象，加上滑鼠監聽事件，當滑鼠左右移動時候，適度的繪製不同影格。大致的原理就是這樣，簡單吧！
實現代碼：
<!DOCTYPE html> <html> <head> <meta charset=utf-8> <title>Full 360 degree View</title> <script> var ctx = null; // global variable 2d context var frame = 1; / / 23 var width = 0; var height = 0; var started = false; var images = new Array(); var startedX = -1; window.onload = function() { var canvas = document.getElementById(fullview_canvas); canvas.width = 440;// window.innerWidth; canvas.height = 440;// window.innerWidth; canvas.height = 691//window; .innerHeight; width = canvas.width; height = canvas.height; var bar = document.getElementById('loadProgressBar'); for(var i=1; i<24; i++) { bar.value = i; if(i<10) { images[i] = new Image (); images[i].src = 0 + i + .jpg; } else { images[i] = new Image(); images[i].src = i + .jpg; } } ctx = canvas.getContext(2d); // mouse event canvas.addEventListener(mousedown, doMouseDown, false); canvas.addalListener('mousemove', doMouseDown, false); canvas.addalListener('mousemove', doMouseMove, false) ; canvas.addEventListener('mouseup', doMouseUp, false); // loaded(); // frame = 1 frame = 1; images[frame].onload = function() { redraw(); bar.style.display = 'none'; } } function doMouseDown(event) { var x = event.pageX; var y = event.pageY; var canvas = event.target; var loc = getPointOnCanvas(canvas, x, y); console.log(mouse down at point( x: + loc.x + , y: + loc.y + )); startedX = loc.x; started = true; } function doMouseMove( event) { var x = event.pageX; var y = event.pageY; var canvas = event.target; var loc = getPointOnCanvas(canvas, x, y); if (started) { var count = Math.floor(Math.abs((startedX - loc.x)/30)); var frameIndex = Math.floor((startedX - loc.x)/30); while(count > 0) { console.log(frameIndex = + frameIndex); count--; if(frameIndex > 0) { frameIndex--; frame++; } else if(frameIndex < 0) { frameIndex++; frame--; } else if(frameIndex == 0ameIndex++; frame--; } else if(frameIndex == 0) {break; 0if(if(ifif. frame >= 24) { frame = 1; } if(frame <= 0) { frame = 23; } redraw(); } } } function doMouseUp(event) { console.log(mouse up now); if (started) { doMouseMove(event); startedX = -1; started = false; } } function getPointOnCanvas(canvas, x, y) { var bbox = canvas.getBoundingClientRect(); return { x: x - bbox.left * (canvas.width / bbox.width), y: y - bbox.top * (canvas.height / bbox.height) }; } function loaded() { setTimeout( update, 1000/8); } function redraw() { // var imageObj = document.createElement(img); // var imageObj = new Image(); var imageObj = images[frame]; ctx.clearRect(0, 0, width, height) ctx.drawImage(imageObj, wid , height); } function update() { redraw(); frame++; if (frame >= 23) frame = 1; setTimeout( update, 1000/8); } </script> </head> <body> <progress id=loadProgressBar value=0 max=23> </progress> <canvas id=fullview_canvas></canvas> <button onclick=loaded()>Auto Play</button> </body> </html>Demo演示文件下載地址-> fullview.rar
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持VeVb武林網。