vec3 luminance;
};
-const float pi = 3.1415926535;
const float mie_asymmetry = 0.8;
uniform sampler2D transmittance_lookup;
float rayleigh_phase(float cos_theta)
{
- return 3.0*(1.0+cos_theta*cos_theta)/(16.0*pi);
+ return 3.0*(1.0+cos_theta*cos_theta)/(16.0*PI);
}
vec3 mie_density(vec3 base, float height)
float g = mie_asymmetry;
float num = (1.0-g*g)*(1.0+cos_theta*cos_theta);
float denom = (2.0+g*g)*pow(1.0+g*g-2.0*g*cos_theta, 1.5);
- return 3.0/(8.0*pi)*num/denom;
+ return 3.0/(8.0*PI)*num/denom;
}
vec3 ozone_density(vec3 base, float height)
if(d_sq>r_sq)
return -1.0;
- float offset = sqrt(r_sq-d_sq);
- if(offset<t)
- return t-offset;
- else if(offset>-t)
- return t+offset;
- else
- return -1.0;
+ float offset = sqrt(r_sq-d_sq)*sign(sphere_radius);
+ return t-offset;
}
#pragma MSP stage(fragment)
vec3 path_extinction = vec3(0.0);
float ground_t = ray_sphere_intersect(pos, look_dir, planet_center, planet_radius);
- float space_t = ray_sphere_intersect(pos, look_dir, planet_center, planet_radius+atmosphere_thickness);
+ float space_t = ray_sphere_intersect(pos, look_dir, planet_center, -(planet_radius+atmosphere_thickness));
float ray_length = (ground_t>0.0 ? ground_t : space_t);
float step_size = ray_length/n_steps;
AtmosphericEvents ev = calculate_events(height);
vec3 transmittance = exp(-path_extinction);
- vec3 in_transmittance = texture(transmittance_lookup, vec2(sqrt(height/atmosphere_thickness), light_z)).rgb;
- vec3 in_luminance = (ev.rayleigh_scatter*p_rayleigh+ev.mie_scatter*p_mie)*step_size;
- if(i==n_steps && ground_t>0.0)
- in_luminance += ground_albedo*light_z/pi;
- path_luminance += transmittance*in_transmittance*in_luminance;
+ float in_ground_t = ray_sphere_intersect(pos, light_dir, planet_center, planet_radius);
+ if(in_ground_t<0.0)
+ {
+ vec3 in_transmittance = texture(transmittance_lookup, vec2(sqrt(height/atmosphere_thickness), light_z)).rgb;
+ vec3 in_luminance = (ev.rayleigh_scatter*p_rayleigh+ev.mie_scatter*p_mie)*step_size;
+ if(i==n_steps && ground_t>0.0 && light_z>0.0)
+ in_luminance += ground_albedo*light_z/PI;
+ path_luminance += transmittance*in_transmittance*in_luminance;
+ }
path_extinction += total_extinction(ev)*step_size;
pos += look_dir*step_size;