cesiumDemo/Source/Shaders/Builtin/Constants/ellipsoidRadii.glsl

/**
 * The radius of the WGS84 ellipsoid.
 *
 * @name czm_ellipsoidRadii
 * @glslConstant
 */
const vec3 czm_ellipsoidRadii = vec3(6378137.0, 6378137.0, 6356752.314245);