feat: apply wind settings to clouds

Changes in the cloud shader were necessary; texture reads are multiplied with a wind-direction

Refs: #312

World/Environment/WorldEnvironment.gd

@@ -58,6 +58,8 @@ func apply_wind_direction(new_wind_direction):
 func apply_wind():
 	var rotated_vector = Vector2.UP.rotated(deg_to_rad(wind_direction))
 
+	environment.sky.get_material().set_shader_parameter("_time_scale", remap(wind_speed, 0, 50, 0, 20))
+	environment.sky.get_material().set_shader_parameter("wind_direction", -rotated_vector)
 	$Rain.wind_direction = Vector3(rotated_vector.x, -1, rotated_vector.y)
 	$Rain.wind_speed = wind_speed
 

World/Environment/WorldEnvironment.tscn

@@ -10,10 +10,10 @@
 
 [sub_resource type="ShaderMaterial" id="ShaderMaterial_ywyjs"]
 shader = ExtResource("1_p31xn")
-shader_parameter/wind_direction = Vector2(1, 0)
-shader_parameter/_density = 0.137
-shader_parameter/cloud_coverage = 0.461
-shader_parameter/_time_scale = 1.0
+shader_parameter/wind_direction = Vector2(1, 1)
+shader_parameter/_density = 0.2
+shader_parameter/cloud_coverage = 0.32
+shader_parameter/_time_scale = 20.0
 shader_parameter/_time_offset = 0.0
 shader_parameter/rayleigh = 2.0
 shader_parameter/rayleigh_color = Color(0.26, 0.41, 0.58, 1)

addons/clouds/clouds.gdshader

@@ -7,7 +7,8 @@ uniform sampler3D worlnoise : filter_linear_mipmap, repeat_enable;
 uniform sampler3D perlworlnoise : filter_linear_mipmap, repeat_enable;
 uniform sampler2D weathermap : filter_linear_mipmap, repeat_enable;
 
-uniform float _density : hint_range(0.01, 0.2) = 0.05;
+uniform vec2 wind_direction = vec2(1, 0);
+uniform float _density : hint_range(0.05, 0.2) = 0.05;
 uniform float cloud_coverage :hint_range(0.1, 1.0) = 0.25;
 uniform float _time_scale :hint_range(0.0, 20.0) = 1.0;
 uniform float _time_offset : hint_range(0.0, 1000.0, 0.5) = 0.0;
@@ -141,16 +142,15 @@ float intersectSphere(vec3 pos, vec3 dir,float r) {
 float density(vec3 pip, vec3 weather, float mip) {
 	float time = TIME * _time_scale;
 	vec3 p = pip;
-	p.x += time * 10.0 + _time_offset;
 	float height_fraction = GetHeightFractionForPoint(length(p));
+	p.xz += time * 20.0 * normalize(wind_direction) * 0.6;
 	vec4 n = textureLod(perlworlnoise, p.xyz*0.00008, mip-2.0);
 	float fbm = n.g*0.625+n.b*0.25+n.a*0.125;
 	float g = densityHeightGradient(height_fraction, weather.r);
 	float base_cloud = remap(n.r, -(1.0-fbm), 1.0, 0.0, 1.0);
 	float weather_coverage = cloud_coverage*weather.b;
 	base_cloud = remap(base_cloud*g, 1.0-(weather_coverage), 1.0, 0.0, 1.0);
 	base_cloud *= weather_coverage;
-	p.xy -= time * 20.0;
 	vec3 hn = textureLod(worlnoise, p*0.001, mip).rgb;
 	float hfbm = hn.r*0.625+hn.g*0.25+hn.b*0.125;
 	hfbm = mix(hfbm, 1.0-hfbm, clamp(height_fraction*4.0, 0.0, 1.0));
@@ -181,8 +181,8 @@ vec4 march(vec3 pos,  vec3 end, vec3 dir, int depth) {
 	vec3 atmosphere_ground = atmosphere(normalize(vec3(1.0, -1.0, 0.0)));
 
 	const float weather_scale = 0.00006;
-	float time = TIME * 0.003 * _time_scale + 0.005*_time_offset;
-	vec2 weather_pos = vec2(time * 0.9, time);
+	float time = TIME * 0.001 * _time_scale + 0.005 * _time_offset;
+	vec2 weather_pos = time * normalize(wind_direction);
 
 	for (int i = 0; i < depth; i++) {
 		p += dir * ss;