How TO - Slideshow Learn how to create a responsive slideshow with CSS and JavaScript. Slideshow / Carousel A slideshow is used to cycle through elements: ❮ ❯ Create A Slideshow Step 1) Add HTML: Example
This is the first article in a series of articles about three.js.Three.jsis a 3D library that tries to make it as easy as possible to get 3D content on a webpage.
Three.js is often confused with WebGL since more often than not, but not always, three.js uses WebGL to draw 3D.WebGL is a very low-level system that only draws points, lines, and triangles. To do anything useful with WebGL generally requires quite a bit of code and that is where three.js comes in. It handles stuff like scenes, lights, shadows, materials, textures, 3d math, all things that you'd have to write yourself if you were to use WebGL directly.
These tutorials assume you already know JavaScript and, for the most part they will use ES6 style.See here for a terse list of things you're expected to already know. Most browsers that support three.js are auto-updated so most users should be able to run this code. If you'd like to make this code run on really old browsers look into a transpiler likeBabel. Of course users running really old browsers probably have machines that can't run three.js.
When learning most programming languages the first thing people do is make the computer print"Hello World!". For 3D one of the most common first things to do is to make a 3D cube. So let's start with "Hello Cube!"
Before we get started let's try to give you an idea of the structure of a three.js app. A three.js app requires you to create a bunch of objects and connect them together. Here's a diagram that represents a small three.js app
Things to notice about the diagram above.
There is aRenderer. This is arguably the main object of three.js. You pass aSceneand aCamerato aRendererand it renders (draws) the portion of the 3D scene that is inside thefrustumof the camera as a 2D image to a canvas.
There is ascenegraphwhich is a tree like structure, consisting of various objects like aSceneobject, multipleMeshobjects,Lightobjects,Group,Object3D, andCameraobjects. ASceneobject defines the root of the scenegraph and contains properties like the background color and fog. These objects define a hierarchical parent/child tree like structure and represent where objects appear and how they are oriented. Children are positioned and oriented relative to their parent. For example the wheels on a car might be children of the car so that moving and orienting the car's object automatically moves the wheels. You can read more about this inthe article on scenegraphs.
Note in the diagramCamerais half in half out of the scenegraph. This is to represent that in three.js, unlike the other objects, aCameradoes not have to be in the scenegraph to function. Just like other objects, aCamera, as a child of some other object, will move and orient relative to its parent object. There is an example of putting multipleCameraobjects in a scenegraph at the end ofthe article on scenegraphs.
Meshobjects represent drawing a specificGeometrywith a specificMaterial. BothMaterialobjects andGeometryobjects can be used by multipleMeshobjects. For example to draw two blue cubes in different locations we could need twoMeshobjects to represent the position and orientation of each cube. We would only need oneGeometryto hold the vertex data for a cube and we would only need oneMaterialto specify the color blue. BothMeshobjects could reference the sameGeometryobject and the sameMaterialobject.
Geometryobjects represent the vertex data of some piece of geometry like a sphere, cube, plane, dog, cat, human, tree, building, etc... Three.js provides many kinds of built ingeometry primitives. You can alsocreate custom geometryas well asload geometry from files.
<!DOCTYPE html>
<head>
<title>Recipe</title>
<script>
window.onload=function() {
document.getElementById("preview").onclick=processText;
}
function processText() {
var txtBox = document.getElementById("inputbox");
var lines = txtBox.value.split("\n");
// generate HTML version of text
var resultString = "<p>";
for (var i = 0; i < lines.length; i++) {
resultString += lines[i] + "<br />";
}
resultString += "</p>";
// print out to page
var blk = document.getElementById("result");
blk.innerHTML = resultString;
}
</script>
</head>
<body>
<textarea id="inputbox" cols="20" rows="10"></textarea>
<div><button id="preview">Preview</button></div>
<div id="result"></div>
</body>
textarea를 줄별로 처리하기
//줄 바꿈 문자를 기준으로 textarea 문자열을 분리
var txtBox = document.getElementById("inputbox");
var lines = txtBox.value.split("\n");
//내용을 HTML 버전으로 변경
var resultString = "<p>";
for (var i = 0; i < lines.length; i++) {
resultString += lines[i] + "<br>";
}
resultString += "</p>";
//페이지에 출력
var blk = document.getElementById("result");
blk.innerHTML = resultString;
function numberWithCommas(x) {
return x.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}
function comma(num){
var len, point, str;
num = num + "";
point = num.length % 3 ;
len = num.length;
str = num.substring(0, point);
while (point < len) {
if (str != "") str += ",";
str += num.substring(point, point + 3);
point += 3;
}
return str;
}
