参考资料： https://www.wenjiangs.com/wp-content/uploads/three.js/examples/#webgl_framebuffer_texture https://www.wenjiangs.com/wp-content/uploads/three.js/examples/#webgl_lines_fat 利用`renderer.setScissor`方法实现，renderer是WebGLRenderer的实例
参考资料：
https://www.wenjiangs.com/wp-content/uploads/three.js/examples/#webgl_framebuffer_texture
https://www.wenjiangs.com/wp-content/uploads/three.js/examples/#webgl_lines_fat
利用
renderer.setScissor方法实现，renderer是WebGLRenderer的实例