三js画布渲染器,带有Blender JSON文件的Objectloader,对象重叠的透明度?

不管我用的是哪种搅拌器;我选择并导出了其他Blender文件,无论设置如何,它们都会产生这种效果。

下面是我用来放置对象和材质的代码。

var loader = new THREE.ObjectLoader();
            loader.load("../js/lights.json", function(object) {

                   var material = new THREE.MeshToonMaterial( { color: 0x3f3f3f, alphaTest: 0.5 } );
                   object.traverse( function ( child ) {
                    if ( child instanceof THREE.Mesh ) {
                        child.material = material;
                        child.drawMode = THREE.TrianglesDrawMode;
                    };  
                   });
                   object.scale.set(3, 3, 3);
                   object.position.x = 1;
                   object.position.y = 1;
                   object.position.z = 1;
                   object.rotation.set( 25, 25, 25 );
                   scene.add( object );
                }   
            );

var loader = new THREE.ObjectLoader();
            loader.load("../js/lights.json", function(object) {

                   var material = new THREE.MeshBasicMaterial( { color: 0x333333 } );
                   object.traverse( function ( child ) {
                    if ( child instanceof THREE.Mesh ) {
                        child.material = material;
                        child.geometry.computeFaceNormals();
                        child.material.overdraw = 0.5
                    };  
                   });
                   object.scale.set(3, 3, 3);
                   object.position.x = 1;
                   object.position.y = 1;
                   object.position.z = 1;
                   object.rotation.set( 25, 25, 25 );
                   scene.add( object );
                }   
            );