3

我正在尝试将天空盒分配给玩家相机。当相机移动（天空盒也随之移动）时，纹理会被拉伸。如何摆脱这个？

代码：

var textureCube = THREE.ImageUtils.loadTextureCube( urls );
textureCube.format = THREE.RGBFormat;
var shader = THREE.ShaderUtils.lib[ "cube" ];
shader.uniforms[ "tCube" ].value = textureCube;

cubematerial = new THREE.ShaderMaterial({
    fragmentShader: shader.fragmentShader,
    vertexShader: shader.vertexShader,
    uniforms: shader.uniforms,
    depthWrite: false,
    side: THREE.BackSide
});
skyBox = new THREE.Mesh(new THREE.CubeGeometry(1000,1000,1000), cubematerial);
camera.add(skyBox);
4

2 回答 2

2

因此，在深入研究 Three.js 示例之后，我找到了一种方法。http://learningthreejs.com/blog/2011/08/15/lets-do-a-sky/已经过时了。示例中使用的一种方法是将天空盒添加到具有固定摄像机的第二个场景中，并渲染两个场景。查看 webgl_materials_cars.html 示例。

另外因为我使用分配给角色的第三人称相机，我必须从角色相机到天空盒相机进行世界旋转。这可以通过以下方式在渲染时完成：

function render(){
<...>
    skyboxCamera.rotation.setEulerFromRotationMatrix( new THREE.Matrix4().extractRotation( camera.matrixWorld ), skyboxCamera.eulerOrder );
    renderer.render(skyboxScene, skyboxCamera);
    renderer.render(scene, camera);
<...>
}
于 2012-11-25T00:00:19.817 回答
1

我知道这是一个封闭的问题，但我想为未来的寻求者提供一个不需要额外场景的替代方案：

  1. 首先阅读并遵循本教程： http: //learningthreejs.com/blog/2011/08/15/lets-do-a-sky/

  2. 现在创建以下着色器（我将其添加到了three.js ShaderLib，但如果您不想使用three'源代码将其添加到外部）：

    'skybox': {

uniforms: { "tCube": { type: "t", value: null },
            "tFlip": { type: "f", value: -1 } },

vertexShader: [

    "varying vec3 vWorldPosition;",

    THREE.ShaderChunk[ "logdepthbuf_pars_vertex" ],

    "void main() {",

    "   vec4 worldPosition = modelMatrix * vec4( position, 1.0 );",
    "   vWorldPosition = worldPosition.xyz;",

    "   gl_Position = projectionMatrix * modelViewMatrix * vec4( position + cameraPosition, 1.0 );",

        THREE.ShaderChunk[ "logdepthbuf_vertex" ],

    "}"

].join("\n"),

fragmentShader: [

    "uniform samplerCube tCube;",
    "uniform float tFlip;",

    "varying vec3 vWorldPosition;",

    THREE.ShaderChunk[ "logdepthbuf_pars_fragment" ],

    "void main() {",

    "   gl_FragColor = textureCube( tCube, vec3( tFlip * vWorldPosition.x, vWorldPosition.yz ) );",

        THREE.ShaderChunk[ "logdepthbuf_fragment" ],

    "}"

].join("\n")

    },

  3. 像这样创建你的天空盒：

        // urls is a list of textures to use
var cubemap = THREE.ImageUtils.loadTextureCube(urls); 
cubemap.format = THREE.RGBFormat; 

var shader = THREE.ShaderLib['skybox']; // init the skybox shader we created above
shader.uniforms['tCube'].value = cubemap; // apply textures to shader

// create shader material
var skyBoxMaterial = new THREE.ShaderMaterial( {
  fragmentShader: shader.fragmentShader,
  vertexShader: shader.vertexShader,
  uniforms: shader.uniforms,
  depthWrite: false,
  side: THREE.BackSide
});

// create skybox mesh
var skybox = new THREE.Mesh(
  new THREE.CubeGeometry(1000, 1000, 1000),
  skyBoxMaterial
);

        // THIS IS IMPORTANT! or the skybox will get culled after you move the camera too far..
skybox.frustumCulled = false;
于 2014-05-26T13:47:55.390 回答