veloren/assets/voxygen/shaders/include/cloud/regular.glsl
2020-04-23 18:19:40 +01:00

79 lines
2.4 KiB
GLSL

uniform sampler2D t_noise;
const float CLOUD_AVG_HEIGHT = 1025.0;
const float CLOUD_HEIGHT_MIN = CLOUD_AVG_HEIGHT - 30.0;
const float CLOUD_HEIGHT_MAX = CLOUD_AVG_HEIGHT + 30.0;
const float CLOUD_THRESHOLD = 0.27;
const float CLOUD_SCALE = 5.0;
const float CLOUD_DENSITY = 100.0;
float vsum(vec3 v) {
return v.x + v.y + v.z;
}
vec2 cloud_at(vec3 pos) {
vec2 scaled_pos = pos.xy / CLOUD_SCALE;
float tick_offs = 0.0
+ texture(t_noise, scaled_pos * 0.0005 - time_of_day.x * 0.00001).x * 0.5
+ texture(t_noise, scaled_pos * 0.0015).x * 0.15;
float value = (
0.0
+ texture(t_noise, scaled_pos * 0.0003 + tick_offs).x
+ texture(t_noise, scaled_pos * 0.0015 - tick_offs * 2.0).x * 0.5
) / 3.0;
value += (0.0
+ texture(t_noise, scaled_pos * 0.008 + time_of_day.x * 0.0002).x * 0.25
+ texture(t_noise, scaled_pos * 0.02 + tick_offs + time_of_day.x * 0.0002).x * 0.15
) * value;
float density = max((value - CLOUD_THRESHOLD) - abs(pos.z - CLOUD_AVG_HEIGHT) / 200.0, 0.0) * CLOUD_DENSITY;
const float SHADE_GRADIENT = 1.5 / (CLOUD_AVG_HEIGHT - CLOUD_HEIGHT_MIN);
float shade = ((pos.z - CLOUD_AVG_HEIGHT) / (CLOUD_HEIGHT_MAX - CLOUD_HEIGHT_MIN)) * 2.5 + 0.7;
return vec2(shade, density / (1.0 + vsum(abs(pos - cam_pos.xyz)) / 5000));
}
vec4 get_cloud_color(vec3 dir, vec3 origin, float time_of_day, float max_dist, float quality) {
const int ITERS = 12;
const float INCR = 1.0 / ITERS;
float mind = (CLOUD_HEIGHT_MIN - origin.z) / dir.z;
float maxd = (CLOUD_HEIGHT_MAX - origin.z) / dir.z;
float start = max(min(mind, maxd), 0.0);
float delta = min(abs(mind - maxd), max_dist);
float fuzz = sin(texture(t_noise, dir.xz * 100000.0 + tick.x).x * 100.0) * INCR * delta * pow(abs(maxd - mind), 0.3) * 2.0;
float cloud_shade = 1.0;
float passthrough = 1.0;
if ((mind > 0.0 || maxd > 0.0) && start < max_dist) {
float dist = start;
for (int i = 0; i < ITERS; i ++) {
dist += fuzz * 0.01 * min(pow(dist * 0.005, 2.0), 1.0);
vec3 pos = origin + dir * min(dist, max_dist);
vec2 sample = cloud_at(pos);
float integral = sample.y * INCR;
passthrough *= 1.0 - integral;
cloud_shade = mix(cloud_shade, sample.x, passthrough * integral);
dist += INCR * delta;
if (passthrough < 0.1) {
break;
}
}
}
float total_density = 1.0 - passthrough / (1.0 + delta * 0.0001);
total_density = max(total_density - 1.0 / pow(max_dist, 0.25), 0.0); // Hack
return vec4(vec3(cloud_shade), total_density);
}