带有着色材料的接收器上的奇怪阴影

Question

我尝试在shadowMap的接收器上使用ShaderMaterial。 我已经读过，如果正确添加ShaderChunks，就可以完成。

是的，我加入了应有的位置。

THREE.UniformsLib['shadowmap'],
THREE.ShaderChunk[ "shadowmap_pars_vertex" ],
THREE.ShaderChunk[ "shadowmap_vertex" ],
THREE.ShaderChunk[ "shadowmap_pars_fragment" ],
THREE.ShaderChunk[ "shadowmap_fragment" ]

不知何故，我需要添加＆＃39; worldPosition＆＃39;在顶点着色器中（我做了） 然后，出现了一些阴影，但不是我所期望的（来自torusKnot）。

有人可以查看代码并告诉我原因吗？

小提琴：https://jsfiddle.net/jmcjc5u/9jz3se0d/5/

var shaderMaterial = new THREE.ShaderMaterial ({   

uniforms: THREE.UniformsUtils.merge([
 THREE.UniformsLib['common'], 
 THREE.UniformsLib['lights'],
 THREE.UniformsLib['shadowmap'],
]),

vertexShader: [
THREE.ShaderChunk[ "shadowmap_pars_vertex" ],
"void main() {",
"  gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);",
"  vec4 worldPosition = modelMatrix * vec4(position, 1.0);",
THREE.ShaderChunk[ "shadowmap_vertex" ],
"}",
].join('\n'),    
fragmentShader: [
  THREE.ShaderChunk[ "shadowmap_pars_fragment" ],
    "void main() {",
  "  gl_FragColor = vec4 (0.5,0.5,0.5,1.0);",
  THREE.ShaderChunk[ "shadowmap_fragment" ],
  "}",
].join('\n'),               
});