grk/cw 6/shaders/shader_pbr.frag

@@ -19,6 +19,11 @@ uniform vec3 lightColor;
 
 uniform bool atmosphereCheck;
 
+uniform float u_time;
+uniform float cloudLight;
+uniform float cloudIntensity; 
+uniform float cloudSpeed; 
+
 in vec3 vecNormal;
 in vec3 worldPos;
 in vec2 vtc;
@@ -103,8 +108,69 @@ vec3 toneMapping(vec3 color)
 	return mapped;
 }
 
-void main()
-{
+float random (in vec2 st) {
+    return fract(sin(dot(st.xy,
+                         vec2(12.9898,78.233)))*
+        43758.5453123);
+}
+
+float noise (in vec2 st) {
+    vec2 i = floor(st);
+    vec2 f = fract(st);
+
+    // Four corners in 2D of a tile
+    float a = random(i);
+    float b = random(i + vec2(1.0, 0.0));
+    float c = random(i + vec2(0.0, 1.0));
+    float d = random(i + vec2(1.0, 1.0));
+
+    vec2 u = f * f * (3.0 - 2.0 * f);
+
+    return mix(a, b, u.x) +
+            (c - a)* u.y * (1.0 - u.x) +
+            (d - b) * u.x * u.y;
+}
+
+#define OCTAVES 6
+float fbm (in vec2 st) {
+    // Initial values
+    float value = 0.0;
+    float amplitude = .5;
+    float frequency = 0.;
+    //
+    // Loop of octaves
+    for (int i = 0; i < OCTAVES; i++) {
+        value += amplitude * noise(st);
+        st *= 2.;
+        amplitude *= .5;
+    }
+    return value;
+}
+
+vec4 noiseColor() {
+    vec2 st = vtc.xy;
+    vec2 mirroredSt = vec2(1.0 - st.x, st.y);
+    
+    float timeOffset = u_time * cloudSpeed;
+    st.x -= timeOffset;
+    mirroredSt.x += timeOffset; // Inverse direction for mirrored effect
+
+    st.x = fract(st.x);
+    mirroredSt.x = fract(mirroredSt.x);
+
+    vec3 color = vec3(fbm(st * cloudIntensity));
+    vec3 mirroredColor = vec3(fbm(mirroredSt * cloudIntensity));
+
+    float blend = smoothstep(0.45, 0.55, st.x); 
+
+    vec3 finalColor = mix(color, mirroredColor, blend);
+
+    vec4 noiseColor = vec4(finalColor, 1.0);
+
+    return noiseColor;
+}
+
+void main() {
     vec3 normal = normalize(vecNormal);
     vec3 viewDir = normalize(cameraPos - worldPos);
 	vec3 lightDir = normalize(lightPos - worldPos);
@@ -132,5 +198,9 @@ void main()
 
     vec3 pbrColor = vec3(1.0) - exp(-illumination * exposition);
 
-    outColor = vec4(pbrColor, 1);
+    vec4 noiseColor = noiseColor() * min(1, AMBIENT + diffuse) * vec4(lightColor, 0.0) / cloudLight;
+
+    vec3 mixedColor = mix(pbrColor.rgb, noiseColor.rgb, noiseColor.r);
+
+    outColor = vec4(mixedColor, 1.0);
 }

grk/cw 6/shaders/shader_pbr.vert

@@ -11,6 +11,7 @@ uniform mat4 modelMatrix;
 
 out vec3 vecNormal;
 out vec3 worldPos;
+
 out vec2 vtc;
 
 uniform vec3 lightPos;
@@ -25,6 +26,7 @@ void main()
 {
 	worldPos = (modelMatrix * vec4(vertexPosition, 1)).xyz;
 	vecNormal = (modelMatrix * vec4(vertexNormal, 0)).xyz;
+
 	gl_Position = transformation * vec4(vertexPosition, 1.0);
 	
 	vtc = vec2(vertexTexCoord.x, 1.0 - vertexTexCoord.y);

grk/cw 6/src/Planet.hpp

@@ -74,6 +74,10 @@ int HDR_HEIGHT = 1024;
 float lightPower = 8.f;
 glm::vec3 lightColor = glm::vec3(lightPower, lightPower, lightPower);
 
+float cloudLight = 20.f;
+float cloudIntensity = 15.f;
+float cloudSpeed = 0.07f;
+
 glm::mat4 createCameraMatrix() {
 	glm::vec3 cameraSide = glm::normalize(glm::cross(cameraDir, glm::vec3(0.f, 1.f, 0.f)));
 	glm::vec3 cameraUp = glm::normalize(glm::cross(cameraSide, cameraDir));
@@ -191,6 +195,12 @@ void drawPlanetPbr(Core::RenderContext& context, glm::mat4 modelMatrix, GLuint t
 	glUniform3f(glGetUniformLocation(programPbr, "lightPos"), sunPos.x, sunPos.y, sunPos.z);
 	glUniform3f(glGetUniformLocation(programPbr, "lightColor"), lightColor.x, lightColor.y, lightColor.z);
 
+	float time = glfwGetTime();
+	glUniform1f(glGetUniformLocation(programPbr, "u_time"), time);
+	glUniform1f(glGetUniformLocation(programPbr, "cloudLight"), cloudLight);
+	glUniform1f(glGetUniformLocation(programPbr, "cloudIntensity"), cloudIntensity);
+	glUniform1f(glGetUniformLocation(programPbr, "cloudSpeed"), cloudSpeed);
+
 	glUniform1i(glGetUniformLocation(programPbr, "atmosphereCheck"), atmosphereCheck);
 
 	Core::DrawContext(context);