#ifdef OVERWORLD
vec3 GetSkyColor(vec3 viewPos, bool isReflection) {
    vec3 nViewPos = normalize(viewPos);

    float VoU = clamp(dot(nViewPos,  upVec), -1.0, 1.0);
    float VoL = clamp(dot(nViewPos, sunVec), -1.0, 1.0);

    float density = 0.4;
    float nightDensity = 0.65;
    float weatherDensity = 1.5;
    float groundDensity = 0.08 * (4.0 - 3.0 * sunVisibility) *
                          (10.0 * rainStrengthS * rainStrengthS + 1.0);
    
    float exposure = exp2(timeBrightness * 0.75 - 0.75);
    float nightExposure = exp2(-3.5);

    float baseGradient = exp(-(1.0 - pow(1.0 - max(VoU, 0.0), 1.5 - 0.5 * VoL)) / density);

    #if SKY_GROUND > 0
    float groundVoU = clamp(-VoU * 1.015 - 0.015, 0.0, 1.0);
    float ground = 1.0 - exp(-groundDensity * OVERWORLD_FOG_DENSITY / groundVoU);
    #if SKY_GROUND == 1
    if (!isReflection) ground = 1.0;
    #endif
    #else
    float ground = 1.0;
    #endif

    vec3 sky = skyCol * baseGradient / (SKY_I * SKY_I);
    #ifdef SKY_VANILLA
    sky = mix(sky, fogCol * baseGradient, pow(1.0 - max(VoU, 0.0), 4.0));
    #endif
    sky = sky / sqrt(sky * sky + 1.0) * exposure * sunVisibility;

    float sunMix = (VoL * 0.5 + 0.5) * pow(clamp(1.0 - VoU, 0.0, 1.0), 2.0 - sunVisibility) *
                   pow(1.0 - timeBrightness * 0.7, 3.0);
    float horizonMix = pow(1.0 - abs(VoU), 2.5) * 0.125 * (1.0 - timeBrightness * 0.5);
    float lightMix = (1.0 - (1.0 - sunMix) * (1.0 - horizonMix));

    vec3 lightSky = pow(lightSun, vec3(4.0 - sunVisibility)) * baseGradient;
    lightSky = lightSky / (1.0 + lightSky * rainStrength);

    sky = mix(
        sqrt(sky * (1.0 - lightMix)), 
        sqrt(lightSky), 
        lightMix
    );
    sky *= sky;

    float nightGradient = exp(-max(VoU, 0.0) / nightDensity);
    vec3 nightSky = lightNight * lightNight * nightGradient * nightExposure;
    sky = mix(nightSky, sky, sunVisibility * sunVisibility);

    float rainGradient = exp(-max(VoU, 0.0) / weatherDensity);
    vec3 weatherSky = weatherCol.rgb * weatherCol.rgb;
    weatherSky *= GetLuminance(ambientCol / (weatherSky)) * (0.2 * sunVisibility + 0.2);
    sky = mix(sky, weatherSky * rainGradient, rainStrengthS);

    sky *= ground;

    if (cameraPosition.y < 1.0) sky *= exp(2.0 * cameraPosition.y - 2.0);

    return sky;
}

#endif