Question

我加载图像以显示精灵。

但似乎代码在图像完全加载之前进行：

但我不知道如何使用Threejs等待图像完全加载。我可以帮忙吗？

可以在此处测试代码：http://www.planetarium2016.com/sprite.html

这是我的代码：

<html>
    <head>
        <title>My first three.js app</title>
        <style>
            body { margin: 0; }
            canvas { width: 100%; height: 100% }
        </style>
    </head>
    <body>
        <script src="https://rawgithub.com/mrdoob/three.js/master/build/three.js"></script>
        <script>
            var scene = new THREE.Scene();
            var camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 500);
            camera.position.set(0, 10, 100);
            camera.lookAt(new THREE.Vector3(0, 0, 0));
            var renderer = new THREE.WebGLRenderer();
            renderer.setSize( window.innerWidth, window.innerHeight );
            document.body.appendChild( renderer.domElement );

            var material = new THREE.LineBasicMaterial({ color: 0x0000ff });
            var geometry = new THREE.Geometry();
            geometry.vertices.push(new THREE.Vector3(-10, 0, 0));
            geometry.vertices.push(new THREE.Vector3(0, 10, 0));
            geometry.vertices.push(new THREE.Vector3(10, 0, 0));
            geometry.vertices.push(new THREE.Vector3(0, 0, -10));

            var line = new THREE.Line(geometry, material);

            scene.add(line);

            var loader = new THREE.TextureLoader();
            var spriteMap = loader.load("https://codefisher.org/static/images/pastel-svg/256/bullet-star.png");

            //+-----------------------------------------------------------+
            //|   I need here to wait for the image to be fully loaded    |
            //|   This cheat is fool: while (spriteMap.image.width == 0); |
            //+-----------------------------------------------------------+

            var spriteMaterial = new THREE.SpriteMaterial( { map: spriteMap, color: 0xffffff } );
            var sprite = new THREE.Sprite( spriteMaterial );
            sprite.scale.set(256, 256, 1);
            sprite.position.set( 0, 0, 10 );
            scene.add( sprite );

            //camera.position.z = 2;

            var render = function () {
                requestAnimationFrame( render );
                renderer.render(scene, camera);
            };
            render();
        </script>
    </body>
</html>

THREE JS TextureLoader有点旧......

Answer 1

解决方案：https://threejs.org/docs/#api/loaders/TextureLoader

这是解决我问题的代码：

        var url = "https://codefisher.org/static/images/pastel-svg/256/bullet-star.png";
        var loader = new THREE.TextureLoader();
        var spriteMaterial;
        loader.load(url,
            function(texture)
                {
                    spriteMaterial = new THREE.SpriteMaterial( { map: texture, color: 0x0000ff } );
                }

            );
        var sprite = new THREE.Sprite( spriteMaterial );

Answer 2

var loader = new THREE.TextureLoader();
loader.load(
    'img/url/img.png',
    function ( map ) {
        // map var is your image                                                                      
    }, 
    function ( xhr ) {                                                                                    
        if ( xhr.lengthComputable ) {                                                                                       
           console.log( 'percent: ' + (xhr.loaded / xhr.total * 100) );                                                                                   
        }
    },
    function ( err ) {                                                                                      
       console.log( 'An error happened' );
    }
);

三点73

Three.js - 如何等待加载图像？

2 个答案: