我有一个函数,我可以在其中生成一颗恒星,我们开始:
function CreateStar( radius, thickness, isWireframe, starColor) {
// material
var starMaterial = new THREE.MeshLambertMaterial({
color: starColor,
wireframe: isWireframe,
shading: THREE.FlatShading
});
// array for vertices
var vertices = [];
// set "zero" vertex for thickness
vertices.push( new THREE.Vector3(0, 0, thickness) );
// calculate a vertex and a pit for a half of a ray... 5 times for each 72 degrees
var deg = Math.PI / 180; // for me it's easier to work with degrees rather than radians
var maxR, minR;
maxR = radius; // radius for a vertex
var x4Rad = maxR * Math.cos( - 72 * deg );
minR = x4Rad/Math.cos( - 36 * deg ); // radius for a pit
var firstVertex;
for ( var i = 0; i < 5; i++ ){
// vertex
var vertX = maxR * Math.cos( (90 + (72 * i)) * deg );
var vertY = maxR * Math.sin( (90 + (72 * i)) * deg );
if ( i == 0 ) firstVertex = new THREE.Vector3( vertX, vertY, 0 );
vertices.push( new THREE.Vector3( vertX, vertY, 0 ));
// pit
var pitX = minR * Math.cos( (126 + (72 * i)) * deg );
var pitY = minR * Math.sin( (126 + (72 * i)) * deg );
vertices.push( new THREE.Vector3( pitX, pitY, 0 ));
}
vertices.push( firstVertex ); // add the first vertex again to close the contour of the star
var holes = []; // no holes in our contour
var triangles, star;
var geometry = new THREE.Geometry();
geometry.vertices = vertices;
triangles = THREE.Shape.Utils.triangulateShape( vertices, holes ); // triangulation
for ( var j = 0; j < triangles.length; j++ ){
geometry.faces.push( new THREE.Face3( triangles[j][0], triangles[j][1], triangles[j][2] ));
}
star = new THREE.Mesh( geometry, starMaterial );
//star = new THREE.Mesh( new THREE.CubeGeometry(200,200,200), starMaterial);
return star;
}
我的问题是,当我从这个函数返回一个立方体(在这个代码中注释)并添加到场景中时,我会得到一个具有正确阴影的立方体,这取决于定向光源的位置,但是,当我返回一颗恒星并将其添加到场景时,我得到。。。嗯。只是一颗没有颜色的黑色恒星(它是黑色的),没有阴影。。。没有什么那么,为什么我可以将材料应用于立方体,而不能将其应用于恒星呢?
有人能向我解释一下我做错了什么吗?
Three.js r68
也许您只需要重新计算法线。尝试:
geometry.computeFaceNormals();
geometry.computeVertexNormals();
star = new THREE.Mesh( geometry, starMaterial );