three.js：如何让多个材质适用于一个网格

Question

I have a big problem with three.js:

I want a simple cube with a different color on each face. I have tried this way:

// set the scene size
    var WIDTH = jQuery('#showcase').width() - 20, HEIGHT = jQuery('#showcase').height();

    // set some camera attributes
    var VIEW_ANGLE = 45, ASPECT = WIDTH / HEIGHT, NEAR = 0.1, FAR = 10000000;

    this.container = jQuery('#showcase');

    this.renderer = new THREE.WebGLRenderer();
    this.camera = new THREE.PerspectiveCamera(VIEW_ANGLE, ASPECT, NEAR, FAR);
    this.scene = new THREE.Scene();
    this.scene.add(this.camera);

    // camera start position
    this.camera.position.z = this.model.radius;
    this.camera.position.y = this.model.cameraY;
    this.camera.position.x = 0;
    this.camera.lookAt(this.scene.position);

    this.renderer.setSize(WIDTH, HEIGHT);
    this.container.append(this.renderer.domElement);

    //Multiple Colors
    var materials = [new THREE.MeshBasicMaterial({
        color : 0xFF0000
    }), new THREE.MeshBasicMaterial({
        color : 0x00FF00
    }), new THREE.MeshBasicMaterial({
        color : 0x0000FF
    }), new THREE.MeshBasicMaterial({
        color : 0xAA0000
    }), new THREE.MeshBasicMaterial({
        color : 0x00AA00
    }), new THREE.MeshBasicMaterial({
        color : 0x0000AA
    })];

    this.geometry = new THREE.CubeGeometry(100, 100, 100, materials);

    this.mesh = new THREE.Mesh(this.geometry,  new THREE.MeshFaceMaterial());

    this.scene.add(this.mesh);

    // create a point light
    this.pointLight = new THREE.PointLight(0xFFFFFF);
    this.pointLight.position = this.scene.position;
    this.scene.add(this.pointLight);

    this.renderer.render(this.scene, this.camera);

But I get this error message: "Uncaught TypeError: Cannot read property 'map' of undefined" from line 19152 in three.js.

To me it seems to be a problem of the webgl renderer. In most topics I have found here and somewhere else, they were using the canvas renderer. But I want to stay with the webgl renderer.

Does anyone know something about this problem? Thanks a lot:-)

Answer 1

Try this

this.geometry = new THREE.CubeGeometry(100, 100, 100);
this.mesh = new THREE.Mesh(this.geometry, new THREE.MeshFaceMaterial(materials));

Answer 2

maybe try to work with an array.

With three.js 49 (dont of if it works with 57) i used this code for a skybox with different materials:

var axes = new THREE.AxisHelper();
scene.add( axes );

var materialArray = [];
    materialArray.push(new THREE.MeshBasicMaterial( { map: THREE.ImageUtils.loadTexture( 'textures/himmel.jpg' ) }));
    materialArray.push(new THREE.MeshBasicMaterial( { map: THREE.ImageUtils.loadTexture( 'textures/himmel.jpg' ) }));
    materialArray.push(new THREE.MeshBasicMaterial( { map: THREE.ImageUtils.loadTexture( 'textures/himmel.jpg' ) }));
    materialArray.push(new THREE.MeshBasicMaterial( { map: THREE.ImageUtils.loadTexture( 'textures/himmel.jpg' ) }));
    materialArray.push(new THREE.MeshBasicMaterial( { map: THREE.ImageUtils.loadTexture( 'textures/himmel.jpg' ) }));
    materialArray.push(new THREE.MeshBasicMaterial( { map: THREE.ImageUtils.loadTexture( 'textures/himmel.jpg' ) }));
    var skyboxGeom = new THREE.CubeGeometry( 5000, 5000, 5000, 1, 1, 1, materialArray );
    var skybox = new THREE.Mesh( skyboxGeom, new THREE.MeshFaceMaterial() );
    skybox.flipSided = true;
    scene.add( skybox );

Answer 3

Try this also, applying the vertexcolors.

var geom = new THREE.BoxGeometry(20, 20, 20);
var faceIndices = ['a', 'b', 'c'];
var vertexIndex, point;
mat = new THREE.MeshBasicMaterial({
vertexColors: THREE.VertexColors
});
mesh = new THREE.Mesh(geom, mat);
scene.add(mesh);
geom.faces.forEach(function (face) { // loop through faces
for (var i = 0; i < 3; i++) {
vertexIndex = face[ faceIndices]; 
point = geom.vertices[vertexIndex]; 
color = new THREE.Color(
point.x + 0.5, 
point.y + 0.5,
point.z + 0.5
);
face.vertexColors[ i ] = [![the output will be as in the attached picture][1]][1]color; 
}
});