Mainly because CubeMapToSphericalPolynomialTools.ConvertCubeMapTextureToSphericalPolynomial
took 28s, almost all of which are calling CubeMapToSphericalPolynomialTools.ConvertCubeMapToSphericalPolynomial
This is my code
const cubeTexture = new CubeTexture(
"/static/skyboxes/cloudless/TropicalSunnyDay",
this._scene
);
this._skyboxMesh = this._scene.createDefaultSkybox(
cubeTexture,
true,
SKYBOX_SIZE
);