get world coordinates in Cesium

cesiumWorldPosition.glsl

vec4 world() {
    vec4 ndc = vec4(
        2.0 * (gl_FragCoord.xy - czm_viewport.xy) / czm_viewport.zw - 1.0,
        (czm_readDepth(depthTexture, v_textureCoordinates) - czm_viewportTransformation[3][2]) / czm_viewportTransformation[2][2],
        1.0);
    vec4 eye = czm_inverseProjection * ndc;
    return czm_inverseView * eye;
}