threejs学习笔记05---相机透视-正透视

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="js/Three.js"></script>
    <script src="js/Stats.js"></script>
    <script src="js/tween.min.js"></script>

    <style type="text/css">
        div#canvas-frame {
            border: none;
            cursor: pointer;
             100%;
            height: 600px;
            background-color: #EEEEEE;
        }

    </style>
    <script>
        var renderer;
        function initThree(){
            width = document.getElementById('canvas-frame').clientWidth;
            height = document.getElementById('canvas-frame').clientHeight;
            renderer= new THREE.WebGLRenderer({
                antialias:true
            });
            renderer.setSize(width,height);
            document.getElementById('canvas-frame').appendChild(renderer.domElement);
            renderer.setClearColor(0xFFFFFF,1.0);
        }

        var camera;
        function initCamera(){
            //透视投影相机THREE.PerspectiveCamera
             camera = new THREE.PerspectiveCamera(45,width/height,1,10000);
            //正投影相机THREE.OrthographicCamera
            //camera = new THREE.OrthographicCamera( window.innerWidth / - 2, window.innerWidth / 2, window.innerHeight / 2, window.innerHeight / - 2, 10, 1000 );
            camera.position.x=0;
            camera.position.y = 0;
            camera.position.z = 600;
            camera.up.x = 0;
            camera.up.y = 1;
            camera.up.z = 0;
            camera.lookAt({
                x : 0,
                y : 0,
                z : 0
            });
        }

        var scene;
        function initScene(){
            scene = new THREE.Scene();
        }

        var light;
        function initLight(){
            light=new THREE.AmbientLight(0xFF0000);
            light.position.set(100,100,200);
            scene.add(light);

            light=new THREE.PointLight(0xFF0000);
            light.position.set(100,100,200);
            scene.add(light);
        }

        var cube;
        function initObject(){
            var geometry=new THREE.CylinderGeometry(70,100,200);
            var material = new THREE.MeshLambertMaterial({color:0xFFFFFF});
            var mesh = new THREE.Mesh(geometry,material);
            mesh.position=new THREE.Vector3(0,0,0);
            scene.add(mesh);
        }
        function animation(){
            changeFov();
            renderer.render(scene, camera);
            requestAnimationFrame(animation);
        }

        function setCameraFov(fov){
            camera.fov = fov;
            //视角fov：这个最难理解,我的理解是,眼睛睁开的角度,即,视角的大小,如果设置为0,
             //       相当你闭上眼睛了,所以什么也看不到,如果为180,那么可以认为你的视界很广阔,
             //       但是在180度的时候，往往物体很小，因为他在你的整个可视区域中的比例变小了。
            camera.updateProjectionMatrix();
        }

        function changeFov(){
            var txtFov = document.getElementById("txtFov").value;
            var val = parseFloat(txtFov);
            setCameraFov(val);
        }

        function threeStart() {
            initThree();
            initCamera();
            initScene();
            initLight();
            initObject();
            animation();

        }
    </script>
</head>
<body onload="threeStart();">
<div></div>
<div id="canvas-frame"></div>
<div>
    Fov:<input type="text" value="45" id="txtFov"/>(0到180的值)
    <p>
        视角fov：这个最难理解,我的理解是,眼睛睁开的角度,即,视角的大小,如果设置为0, <br>
               相当你闭上眼睛了,所以什么也看不到,如果为180,那么可以认为你的视界很广阔,<br>
               但是在180度的时候，往往物体很小，因为他在你的整个可视区域中的比例变小了。
    </p>
</div>
</body>
</html>

　　

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="js/Three.js"></script>
    <script src="js/Stats.js"></script>
    <script src="js/tween.min.js"></script>

    <style type="text/css">
div#canvas-frame {
            border: none;
cursor: pointer;
width: 100%;
height: 600px;
background-color: #EEEEEE;
}

    </style>
    <script>
var renderer;
function initThree(){
width = document.getElementById('canvas-frame').clientWidth;
height = document.getElementById('canvas-frame').clientHeight;
renderer= new THREE.WebGLRenderer({
antialias:true
});
renderer.setSize(width,height);
document.getElementById('canvas-frame').appendChild(renderer.domElement);
renderer.setClearColor(0xFFFFFF,1.0);
        }

var camera;
function initCamera(){
//透视投影相机THREE.PerspectiveCamera
camera = new THREE.PerspectiveCamera(45,width/height,1,10000);
//正投影相机THREE.OrthographicCamera
            //camera = new THREE.OrthographicCamera( window.innerWidth / - 2, window.innerWidth / 2, window.innerHeight / 2, window.innerHeight / - 2, 10, 1000 );
camera.position.x=0;
camera.position.y = 0;
camera.position.z = 600;
camera.up.x = 0;
camera.up.y = 1;
camera.up.z = 0;
camera.lookAt({
x : 0,
y : 0,
z : 0
});
        }

var scene;
function initScene(){
scene = new THREE.Scene();
        }

var light;
function initLight(){
light=new THREE.AmbientLight(0xFF0000);
light.position.set(100,100,200);
scene.add(light);

light=new THREE.PointLight(0xFF0000);
light.position.set(100,100,200);
scene.add(light);
        }

var cube;
function initObject(){
var geometry=new THREE.CylinderGeometry(70,100,200);
var material = new THREE.MeshLambertMaterial({color:0xFFFFFF});
var mesh = new THREE.Mesh(geometry,material);
mesh.position=new THREE.Vector3(0,0,0);
scene.add(mesh);
        }
function animation(){
changeFov();
renderer.render(scene, camera);
requestAnimationFrame(animation);
        }

function setCameraFov(fov){
camera.fov = fov;
//视角fov：这个最难理解,我的理解是,眼睛睁开的角度,即,视角的大小,如果设置为0,
             //       相当你闭上眼睛了,所以什么也看不到,如果为180,那么可以认为你的视界很广阔,
             //       但是在180度的时候，往往物体很小，因为他在你的整个可视区域中的比例变小了。
camera.updateProjectionMatrix();
        }

function changeFov(){
var txtFov = document.getElementById("txtFov").value;
var val = parseFloat(txtFov);
setCameraFov(val);
        }

function threeStart() {
initThree();
initCamera();
initScene();
initLight();
initObject();
animation();

        }
</script>
</head>
<body onload="threeStart();">
<div></div>
<div id="canvas-frame"></div>
<div>
Fov:<input type="text" value="45" id="txtFov"/>(0到180的值)
<p>
视角fov：这个最难理解,我的理解是,眼睛睁开的角度,即,视角的大小,如果设置为0, <br>
相当你闭上眼睛了,所以什么也看不到,如果为180,那么可以认为你的视界很广阔,<br>
但是在180度的时候，往往物体很小，因为他在你的整个可视区域中的比例变小了。
</p>
</div>
</body>
</html>
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原文地址：https://www.cnblogs.com/Webyangbowen/p/8058890.html