text: //This file is automatically rebuilt by the Cesium build process.
  export default "vec3 customShaderStage(vec3 position) {\n\
    #ifdef COMPUTE_POSITION_WC\n\
    // needed so the fragment shader can set fsInput.positionWC\n\
    // Note that this is a 32-bit position which may result in jitter on small\n\
    // scales.\n\
    v_positionWC = (czm_model * vec4(position, 1.0)).xyz;\n\
    #endif\n\
  \n\
    #ifdef HAS_CUSTOM_VERTEX_SHADER  \n\
    // VertexInput and initializeInputStruct() are dynamically generated in JS, \n\
    // see CustomShaderStage.js\n\
    VertexInput vsInput;\n\
    initializeInputStruct(vsInput);\n\
    vertexMain(vsInput, position);\n\
    #endif\n\
  \n\
    return position;\n\
  }\n\
  ";
  