1e66c4104a
- Terrain and clouds and now rendered on the envmap, with correct aerial perspective. - Each face is rendered on a separate frame to help with performance. - All faces are updated every 1.5 minutes. This can be changed through a property.
44 lines
1.4 KiB
GLSL
44 lines
1.4 KiB
GLSL
#version 330 core
|
|
|
|
uniform sampler2D transmittance_tex;
|
|
|
|
uniform float fg_EarthRadius;
|
|
uniform vec3 fg_SunDirectionWorld;
|
|
uniform float fg_CameraDistanceToEarthCenter;
|
|
uniform float fg_SunZenithCosTheta;
|
|
|
|
const float ATMOSPHERE_RADIUS = 6471e3;
|
|
|
|
// atmos_spectral.glsl
|
|
vec4 get_sun_spectral_irradiance();
|
|
vec3 linear_srgb_from_spectral_samples(vec4 L);
|
|
|
|
/*
|
|
* Get the Sun radiance at a point 'p' in world space.
|
|
* We cannot use the Sun extraterrestial irradiance directly because it will be
|
|
* attenuated by the transmittance of the atmospheric medium.
|
|
*/
|
|
vec3 get_sun_radiance(vec3 p)
|
|
{
|
|
float distance_to_earth_center = length(p);
|
|
float normalized_altitude = (distance_to_earth_center - fg_EarthRadius)
|
|
/ (ATMOSPHERE_RADIUS - fg_EarthRadius);
|
|
|
|
vec3 zenith_dir = p / distance_to_earth_center;
|
|
float sun_cos_theta = dot(zenith_dir, fg_SunDirectionWorld);
|
|
|
|
float u = sun_cos_theta * 0.5 + 0.5;
|
|
float v = clamp(normalized_altitude, 0.0, 1.0);
|
|
vec4 transmittance = texture(transmittance_tex, vec2(u, v));
|
|
|
|
vec4 L = get_sun_spectral_irradiance() * transmittance;
|
|
return linear_srgb_from_spectral_samples(L);
|
|
}
|
|
|
|
vec3 get_sun_radiance_sea_level()
|
|
{
|
|
vec2 uv = vec2(fg_SunZenithCosTheta * 0.5 + 0.5, 0.0);
|
|
vec4 transmittance = texture(transmittance_tex, uv);
|
|
vec4 L = get_sun_spectral_irradiance() * transmittance;
|
|
return linear_srgb_from_spectral_samples(L);
|
|
}
|