问ThreeJS -如何将3d对象转换为2d表示

EN

//create someplane to project to
var plane = new THREE.Plane().setFromCoplanarPoints(pointA,pointB,pointC)
//create some geometry to flatten..
var geometry = new THREE.BufferGeometry();
fillGeometry(geometry);

var positionAttr = geometry.getAttribute("position");
for(var i = 0; i < positionAttr.array.length; i+=3)
{
    var point = new THREE.Vector3(positionAttr.array[i],positionAttr.array[i+1],positionAttr.array[i+2]);
    var projectedPoint = plane.projectPoint();
    positionAttr.array[i] = projectedPoint.x;
    positionAttr.array[i+1] = projectedPoint.y;
    positionAttr.array[i+2] = projectedPoint.z;
}
positionAttr.needsUpdate = true;