veloren/assets/voxygen/shaders/include/cloud/regular.glsl

76 lines
2.3 KiB
GLSL

uniform sampler2D t_noise;
const float CLOUD_AVG_HEIGHT = 1025.0;
const float CLOUD_HEIGHT_MIN = CLOUD_AVG_HEIGHT - 50.0;
const float CLOUD_HEIGHT_MAX = CLOUD_AVG_HEIGHT + 50.0;
const float CLOUD_THRESHOLD = 0.3;
const float CLOUD_SCALE = 5.0;
const float CLOUD_DENSITY = 50.0;
float vsum(vec3 v) {
return v.x + v.y + v.z;
}
vec2 cloud_at(vec3 pos) {
float tick_offs = 0.0
+ texture(t_noise, pos.xy * 0.0001 - tick.x * 0.001).x * 0.5
+ texture(t_noise, pos.xy * 0.000003).x * 5.0;
float value = (
0.0
+ texture(t_noise, pos.xy / CLOUD_SCALE * 0.0003 + tick_offs).x
+ texture(t_noise, pos.xy / CLOUD_SCALE * 0.0009 - tick_offs).x * 0.5
+ texture(t_noise, pos.xy / CLOUD_SCALE * 0.0025 - tick.x * 0.01).x * 0.25
+ texture(t_noise, pos.xy / CLOUD_SCALE * 0.008 + tick.x * 0.02).x * 0.15
+ texture(t_noise, pos.xy / CLOUD_SCALE * 0.02 + tick_offs + tick.x * 0.02).x * 0.1
) / 3.0;
float density = max((value - CLOUD_THRESHOLD) - abs(pos.z - CLOUD_AVG_HEIGHT) / 400.0, 0.0) * CLOUD_DENSITY;
float shade = ((pos.z - CLOUD_AVG_HEIGHT) * 1.8 / (CLOUD_AVG_HEIGHT - CLOUD_HEIGHT_MIN) + 0.5);
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 float INCR = 0.1;
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);
bool do_cast = true;
if (mind < 0.0 && maxd < 0.0) {
do_cast = false;
}
float incr = INCR;
float fuzz = sin(texture(t_noise, dir.xz * 100000.0 + tick.x).x * 100.0) * incr * delta;
float cloud_shade = 1.0;
float passthrough = 1.0;
if (do_cast) {
for (float d = 0.0; d < 1.0; d += incr) {
float dist = start + d * delta;
dist += fuzz * pow(maxd - mind, 0.5) * 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 *= max(1.0 - integral, 0.0);
cloud_shade = mix(cloud_shade, sample.x, passthrough * integral);
}
}
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);
}