Panoramic textured sky with clouds.
This shader was originally made by drift and posted on shadertoy.
https://www.shadertoy.com/view/4tdSWr
It uses a noise generation function instead of a noise texture. I’ve exposed the variables to make tweaking the properties that much easier.
Shader code
shader_type sky;
render_mode use_half_res_pass;
uniform sampler2D source_panorama : filter_linear, source_color, hint_default_black;
uniform bool add_clouds = true;
uniform bool clouds_below = false;
uniform float cloud_scale : hint_range(0.0, 1.0, 0.01) = 0.25;
uniform float speed : hint_range(0.0, 0.25, 0.001) = 0.002;
uniform float cloud_dark : hint_range(0.0, 1.0, 0.01) = 0.5;
uniform float cloud_light : hint_range(0.0, 1.0, 0.01) = 0.3;
uniform float cloud_cover : hint_range(0.0, 1.0, 0.01) = 0.2;
uniform float cloud_alpha : hint_range(0.0, 10.0, 0.01) = 8.0;
uniform float sky_tint : hint_range(0.0, 1.0, 0.001) = 0.5;
uniform float height_offset : hint_range(0.0, 1.0, 0.001) = 0.2;
uniform float sky_contribution : hint_range(0.0, 1.0, 0.1) = 0.5;
const mat2 m = mat2(vec2( 1.6, 1.2), vec2(-1.2, 1.6));
vec2 hash( vec2 p ) {
p = vec2(dot(p, vec2(127.1, 311.7)), dot(p, vec2(269.5, 183.3)));
return -1.0 + 2.0 * fract(sin(p) * 43758.5453123);
}
float noise( in vec2 p ) {
const float K1 = 0.366025404; // (sqrt(3)-1)/2;
const float K2 = 0.211324865; // (3-sqrt(3))/6;
vec2 i = floor(p + (p.x + p.y)*K1);
vec2 a = p - i + (i.x + i.y) * K2;
vec2 o = (a.x > a.y) ? vec2(1.0, 0.0) : vec2(0.0, 1.0);
vec2 b = a - o + K2;
vec2 c = a - 1.0 + 2.0 * K2;
vec3 h = max(0.5 - vec3(dot(a, a), dot(b, b), dot(c, c)), 0.0 );
vec3 n = h * h * h * h * vec3(dot(a, hash(i + 0.0)), dot(b, hash(i + o)), dot(c, hash(i + 1.0)));
return dot(n, vec3(70.0));
}
float fbm(vec2 n) {
float total = 0.0, amplitude = 0.1;
for (int i = 0; i < 7; i++) {
total += noise(n) * amplitude;
n = m * n;
amplitude *= 0.4;
}
return total;
}
void sky() {
COLOR = texture(source_panorama, SKY_COORDS).rgb;
if(AT_CUBEMAP_PASS){
COLOR *= sky_contribution;
}else if(add_clouds){
vec3 normal = normalize(EYEDIR);
vec3 plane_intersect = normal / (normal.y + height_offset);
if(clouds_below){
plane_intersect = normal / -(normal.y - height_offset);
}
vec2 p = plane_intersect.xz;
p.y *= -1.0;
vec2 uv = p;
float time = TIME * speed;
float q = fbm(uv * cloud_scale * 0.5);
//ridged noise shape
float r = 0.0;
uv *= cloud_scale;
uv -= q - time;
float weight = 0.8;
for(int i = 0; i < 8; i++){
r += abs(weight*noise( uv ));
uv = m*uv + time;
weight *= 0.7;
}
//noise shape
float f = 0.0;
uv = p;
uv *= cloud_scale;
uv -= q - time;
weight = 0.7;
for(int i = 0; i < 8; i++){
f += weight*noise( uv );
uv = m*uv + time;
weight *= 0.6;
}
f *= r + f;
//noise colour
float c = 0.0;
time = TIME * speed * 2.0;
uv = p;
uv *= cloud_scale * 2.0;
uv -= q - time;
weight = 0.4;
for(int i = 0; i < 7; i++){
c += weight*noise( uv );
uv = m*uv + time;
weight *= 0.6;
}
//noise ridge colour
float c1 = 0.0;
time = TIME * speed * 3.0;
uv = p;
uv *= cloud_scale * 3.0;
uv -= q - time;
weight = 0.4;
for (int i = 0; i < 7; i++){
c1 += abs(weight*noise( uv ));
uv = m*uv + time;
weight *= 0.6;
}
c += c1;
vec3 skycolour = COLOR;
vec3 cloudcolour = vec3(1.1, 1.1, 0.9) * clamp((cloud_dark + cloud_light * c), 0.0, 1.0);
float horizon_fall_off = max(normal.y, 0.0);
if(clouds_below){
horizon_fall_off = max(-normal.y, 0.0);
}
f = cloud_cover + cloud_alpha * f * r;
vec3 result = mix(skycolour, clamp(sky_tint * skycolour + cloudcolour, 0.0, 1.0), clamp(f + c, 0.0, 1.0) * horizon_fall_off);
// Convert the color to black and white.
COLOR = vec3((result.r + result.g + result.b) / 3.0);
}
}
Thanks a lot!