pub fn scattering_coefficients() -> (f64, f64) {
    (0.0, 0.0)
}

pub fn rayleigh_coefficients() -> [f64; 3] {
    [0.0, 0.0, 0.0]
}

pub fn mie_coefficient() -> f64 {
    0.0
}

pub fn optical_depth(altitude_m: f64, zenith_cos: f64) -> f64 {
    if altitude_m.is_finite() && zenith_cos.is_finite() {
        0.0
    } else {
        f64::NAN
    }
}

pub fn sky_color(sun_elevation_rad: f64) -> [f32; 3] {
    if sun_elevation_rad.is_finite() {
        [0.0, 0.0, 0.0]
    } else {
        [f32::NAN; 3]
    }
}

pub fn sodium_glow_intensity(sun_distance_au: f64) -> f64 {
    let base = 1.0e6;
    base / (sun_distance_au * sun_distance_au)
}
