fix artifacts (cloud lines, sunset lines, mie weirdness)

src/components/Renderer.svelte

@@ -71,7 +71,7 @@
 
     bloom = new SelectiveBloomEffect(scene, camera, {
       intensity: $bloomIntensity,
-      luminanceThreshold: 1.2, //0.5,
+      luminanceThreshold: 1.5, //0.5,
       luminanceSmoothing: 0.7,
       blendFunction: BlendFunction.ADD,
       radius: .9, //.99,

src/scenes/Space.svelte

@@ -196,9 +196,9 @@
 
   <T.Mesh
     visible={$skyVisible}
-    scale.x={AU}
-    scale.y={AU}
-    scale.z={AU}
+    scale.x={$planetRadius + $atmosphereThickness}
+    scale.y={$planetRadius + $atmosphereThickness}
+    scale.z={$planetRadius + $atmosphereThickness}
     renderOrder={2}
   >
     <T.IcosahedronGeometry args={[1, 32]} />

src/shaders/sky/fragment.glsl

@@ -189,8 +189,8 @@ float miePhase(float mu, float g){
   // phases
   float mumu = mu * mu;
   float gg = g * g;
-  return THREE_OVER_8_PI * (pow(1.0 - gg, 2.)) / (pow(1.0 + gg - 2.0 * mu * g, 1.5));
-  // return THREE_OVER_8_PI * ((1.0 - gg) * (mumu + 1.0)) / (pow(1.0 + gg - 2.0 * mu * g, 1.5) * (2.0 + gg));
+  // return THREE_OVER_8_PI * (pow(1.0 - gg, 2.)) / (pow(1.0 + gg - 2.0 * mu * g, 1.5));
+  return THREE_OVER_8_PI * ((1.0 - gg) * (mumu + 1.0)) / (pow(1.0 + gg - 2.0 * mu * g, 1.5) * (2.0 + gg));
 }
 
 vec2 getPhases(float mu, float g){
@@ -199,8 +199,8 @@ vec2 getPhases(float mu, float g){
   float gg = g * g;
   float rayleighP = THREE_OVER_16_PI + THREE_OVER_16_PI * mumu;
   // alternate mie that may be better
-  float mieP = THREE_OVER_8_PI * (pow(1.0 - gg, 2.)) / (pow(1.0 + gg - 2.0 * mu * g, 1.5));
-  // float mieP = THREE_OVER_8_PI * ((1.0 - gg) * (mumu + 1.0)) / (pow(1.0 + gg - 2.0 * mu * g, 1.5) * (2.0 + gg));
+  // float mieP = THREE_OVER_8_PI * (pow(1.0 - gg, 2.)) / (pow(1.0 + gg - 2.0 * mu * g, 1.5));
+  float mieP = THREE_OVER_8_PI * ((1.0 - gg) * (mumu + 1.0)) / (pow(1.0 + gg - 2.0 * mu * g, 1.5) * (2.0 + gg));
   return vec2(rayleighP, mieP);
 }
 
@@ -422,26 +422,27 @@ vec4 scattering(
     pos += dr;
     vec2 odStep = opticalDensity(length(pos), scaleHeights, planetRadius) * ds;
     primaryDepth += odStep;
-    vec2 intPlanet2 = raySphereIntersection(pos, sSun, planetRadius);
-    // if the ray intersects the planet, no light comes this way
-    if (!intersectsOutside(intPlanet2)) {
-      float u = umbra(pos, rApparentSun, sunPosition, rApparentMoon, moonPosition);
-      // u = intersectsOutside(intPlanet2) ? 0.0 : u;
-
-      vec2 intAtmosphere2 = raySphereIntersection(pos, sSun, atmosphereRadius);
-      vec3 exit = pos + intAtmosphere2.y * sSun;
-
-      vec2 secondaryDepth = opticalDepths(pos, exit, scaleHeights, planetRadius, steps.y);
-      // vec2 secondaryDepth = getOpticalDepths(pos, normalize(exit - pos), scaleHeights, planetRadius, atmosphereRadius);
-      // vec2 secondaryDepth = vec2(0.0);
-      vec2 depth = primaryDepth + secondaryDepth;
-      vec4 alpha = vec4(vec3(depth.x), depth.y) * scatteringCoefficients;
-      vec3 transmittance = exp(- alpha.xyz - alpha.w);
-      vec3 scatter = u * transmittance;
-
-      rayleighT += scatter * odStep.x;
-      mieT += scatter * odStep.y;
-    }
+
+    // if the ray intersects the planet, no light comes this way...but..
+    // I tried doing this and it created lines in the atmosphere
+    // vec2 intPlanet2 = raySphereIntersection(pos, sSun, planetRadius);
+
+    float u = umbra(pos, rApparentSun, sunPosition, rApparentMoon, moonPosition);
+    // u = intersectsOutside(intPlanet2) ? 0.0 : u;
+
+    vec2 intAtmosphere2 = raySphereIntersection(pos, sSun, atmosphereRadius);
+    vec3 exit = pos + intAtmosphere2.y * sSun;
+
+    vec2 secondaryDepth = opticalDepths(pos, exit, scaleHeights, planetRadius, steps.y);
+    // vec2 secondaryDepth = getOpticalDepths(pos, normalize(exit - pos), scaleHeights, planetRadius, atmosphereRadius);
+    // vec2 secondaryDepth = vec2(0.0);
+    vec2 depth = primaryDepth + secondaryDepth;
+    vec4 alpha = vec4(vec3(depth.x), depth.y) * scatteringCoefficients;
+    vec3 transmittance = exp(- alpha.xyz - alpha.w);
+    vec3 scatter = u * transmittance;
+
+    rayleighT += scatter * odStep.x;
+    mieT += scatter * odStep.y;
   }
 
   float mu = dot(rayDir, sSun);
@@ -462,19 +463,20 @@ vec4 scattering(
     vec2 cloudInt = raySphereIntersection(rayOrigin, rayDir, planetRadius + cloudHeight);
     if (intersectsInsideOnly(cloudInt)){
       float cloudPhase = miePhase(mu, cloudMie);
-      vec3 cloudLayer = cloudSize * 900. * (rayDir * (cloudInt.y + 0.2 * atmosphereThickness * noise(vUv))) / atmosphereRadius;
+      vec3 cloudLayer = cloudSize * 900. * (rayDir * (cloudInt.y + 0.2 * atmosphereThickness)) / atmosphereRadius;
       cloudAmount = cloudThickness * smoothstep(0., 1.0, fbm(cloudLayer + windSpeed * time) - cloudThreshold);
       // float cloudAmount = 2. * getPhases(rayDir, sSun, 0.5 + 0.4 * fbm(cloudLayer * 20.)).y;
-      cloud = 1e-6 * I0 * cloudAmount * cloudPhase * rayleighT;
       cloudAbsorptionAmount = cloudAbsorption * cloudAmount;
+      cloud = 1e-6 * I0 * cloudAmount * cloudPhase * rayleighT;
     }
   }
 
   // final scattering
-  vec3 scatter = I0 * rayleighT * phases.x * scatteringCoefficients.xyz + I0 * mieT * phases.y * scatteringCoefficients.w;
+  vec3 scatter = I0 * rayleighT * phases.x * scatteringCoefficients.xyz + I0 * mieT * (phases.y * scatteringCoefficients.w - cloudAbsorption * 1e-6);
+  scatter = clamp(scatter, 0.0, I0);
   // opacity of the atmosphere
   float opacity = dot(primaryDepth, vec2(0.2 * length(rayleighCoefficients), mieCoefficient)) + cloudAbsorptionAmount;
-  return vec4((1. - cloudAbsorptionAmount) * (scatter + sunDiskColor) + cloud, clamp(opacity, 0.0, 1.0));
+  return vec4((1. - cloudAbsorptionAmount) * (scatter + sunDiskColor + cloud), clamp(opacity, 0.0, 1.0));
 }
 
 void main() {

src/store/environment.js

@@ -89,20 +89,24 @@ export const moonPosition = derived(
       .applyAxisAngle($moonAxis, $moonRightAscention)
 )
 
-const getMie = (n, k) => {
+const getScatteringScale = (n, k) => {
   return k * 1e26 * 8 * Math.pow(Math.PI, 3) * Math.pow((n * n - 1), 2) / 3 / 2.547e+25
 }
 
+const getMie = (n, k) => {
+  const a = getScatteringScale(n, k)
+  return 0.01 * a
+}
+
 const getRayleigh = (n, k) => {
   const rgb = [680, 510, 440]
   const corr = 1e10
-  const a = getMie(n, k)
+  const a = getScatteringScale(n, k)
   const r = new Vector3(
     corr * a * Math.pow(1 / rgb[0], 4),
     corr * a * Math.pow(1 / rgb[1], 4),
     corr * a * Math.pow(1 / rgb[2], 4)
   )
-  console.log(r, a)
   return r
 }
 
@@ -112,22 +116,28 @@ const print = (val, ...args) => {
 }
 
 export const sunIntensity = writable(25)
-export const overrideRayleigh = writable(false)
-// 5.5e-6, 13.0e-6, 22.4e-6
-export const rayleighRed = writable(5.5)
-export const rayleighGreen = writable(13)
-export const rayleighBlue = writable(22.4)
-export const rayleighScaleHeight = writable(8e3)
-export const mieCoefficient = writable(4.4e-6)
-export const mieScaleHeight = writable(1.2e3)
-export const mieDirectional = writable(-0.758)
 export const airIndexRefraction = writable(1.0003)
 export const airSurfacePressure = writable(101.3e3)
 export const airSurfaceTemperature = writable(288)
 export const airDensityFactor = derived(
   [airSurfacePressure, airSurfaceTemperature],
   ([$P, $T]) => print((288 / 101.3e3) * ($P / $T), $P, $T)
 )
+export const overrideRayleigh = writable(false)
+// 5.5e-6, 13.0e-6, 22.4e-6
+export const rayleighRed = writable(5.5)
+export const rayleighGreen = writable(13)
+export const rayleighBlue = writable(22.4)
+export const rayleighScaleHeight = writable(8e3)
+export const mieCoefficient = derived(
+  [airIndexRefraction, airDensityFactor],
+  ([$n, $air]) => {
+    const m = getMie($n, $air)
+    return m //new Vector3(m, m, m)
+  }
+)
+export const mieScaleHeight = writable(1.2e3)
+export const mieDirectional = writable(0.758)
 export const rayleighCoefficient = derived(
   [airIndexRefraction, airDensityFactor, overrideRayleigh, rayleighRed, rayleighGreen, rayleighBlue],
   ([$n, $air, $overrideRayleigh, $rayleighRed, $rayleighGreen, $rayleighBlue]) => {