Bliss-Shader/shaders/lib/volumetricClouds.glsl
2024-11-16 21:40:25 +01:00

669 lines
23 KiB
GLSL

#ifdef HQ_CLOUDS
int maxIT_clouds = minRayMarchSteps;
int maxIT = maxRayMarchSteps;
const int cloudLoD = cloud_LevelOfDetail;
const int cloudShadowLoD = cloud_ShadowLevelOfDetail;
#else
int maxIT_clouds = minRayMarchStepsLQ;
int maxIT = maxRayMarchStepsLQ;
const int cloudLoD = cloud_LevelOfDetailLQ;
const int cloudShadowLoD = cloud_ShadowLevelOfDetailLQ;
#endif
uniform int worldTime;
#define WEATHERCLOUDS
#include "/lib/climate_settings.glsl"
#if defined Daily_Weather
flat varying vec4 dailyWeatherParams0;
flat varying vec4 dailyWeatherParams1;
#else
vec4 dailyWeatherParams0 = vec4(CloudLayer0_coverage, CloudLayer1_coverage, CloudLayer2_coverage, 0.0);
vec4 dailyWeatherParams1 = vec4(CloudLayer0_density, CloudLayer1_density, CloudLayer2_density, 0.0);
#endif
float LAYER0_width = 100.0;
float LAYER0_minHEIGHT = CloudLayer0_height;
float LAYER0_maxHEIGHT = LAYER0_width + LAYER0_minHEIGHT;
float LAYER1_width = 100.0;
float LAYER1_minHEIGHT = max(CloudLayer1_height, LAYER0_maxHEIGHT);
float LAYER1_maxHEIGHT = LAYER1_width + LAYER1_minHEIGHT;
float LAYER2_HEIGHT = max(CloudLayer2_height, LAYER1_maxHEIGHT);
// float LAYER0_COVERAGE = mix(pow(dailyWeatherParams0.x*2.0,0.2), 0.9, rainStrength);
// float LAYER1_COVERAGE = mix(pow(dailyWeatherParams0.y*2.0,0.2), 0.8, rainStrength);
// float LAYER2_COVERAGE = mix(pow(dailyWeatherParams0.z*2.0,0.2), 1.3, rainStrength);
float LAYER0_COVERAGE = mix(dailyWeatherParams0.x, 0.95, rainStrength);
float LAYER1_COVERAGE = mix(dailyWeatherParams0.y, 0.0, rainStrength);
float LAYER2_COVERAGE = mix(dailyWeatherParams0.z, 1.5, rainStrength);
float LAYER0_DENSITY = mix(dailyWeatherParams1.x,1.0,rainStrength);
float LAYER1_DENSITY = mix(dailyWeatherParams1.y,0.0,rainStrength);
float LAYER2_DENSITY = mix(dailyWeatherParams1.z,0.05,rainStrength);
uniform int worldDay;
float cloud_movement = (worldTime + mod(worldDay,100)*24000.0) / 24.0 * Cloud_Speed;
//3D noise from 2d texture
float densityAtPos(in vec3 pos){
pos /= 18.;
pos.xz *= 0.5;
vec3 p = floor(pos);
vec3 f = fract(pos);
vec2 uv = p.xz + f.xz + p.y * vec2(0.0,193.0);
vec2 coord = uv / 512.0;
//The y channel has an offset to avoid using two textures fetches
vec2 xy = texture2D(noisetex, coord).yx;
return mix(xy.r,xy.g, f.y);
}
float GetAltostratusDensity(vec3 pos){
float large = 1.0 - texture2D(noisetex, (pos.xz + cloud_movement)/100000.).b;
large = max(large + LAYER2_COVERAGE - 0.7, 0.0);
float medium = 1.0 - texture2D(noisetex, (pos.xz - cloud_movement)/7500. + vec2(-large,1.0-large)/5.0).b;
float shape = max(large - medium*0.4 * clamp(1.5-large,0.0,1.0),0.0);
return shape*shape;
}
float cloudCov(int layer, in vec3 pos, vec3 samplePos, float minHeight, float maxHeight){
float FinalCloudCoverage = 0.0;
float coverage = 0.0;
float Topshape = 0.0;
float Baseshape = 0.0;
float LAYER0_minHEIGHT_FOG = CloudLayer0_height;
float LAYER0_maxHEIGHT_FOG = 100 + LAYER0_minHEIGHT_FOG;
LAYER0_minHEIGHT_FOG = LAYER0_minHEIGHT;
LAYER0_maxHEIGHT_FOG = LAYER0_maxHEIGHT;
float LAYER1_minHEIGHT_FOG = max(CloudLayer1_height, LAYER0_maxHEIGHT);
float LAYER1_maxHEIGHT_FOG = 100 + LAYER1_minHEIGHT_FOG;
LAYER1_minHEIGHT_FOG = LAYER1_minHEIGHT;
LAYER1_maxHEIGHT_FOG = LAYER1_maxHEIGHT;
vec2 SampleCoords0 = vec2(0.0); vec2 SampleCoords1 = vec2(0.0);
float CloudSmall = 0.0;
if(layer == 0){
SampleCoords0 = (samplePos.xz + cloud_movement) / 5000 ;
SampleCoords1 = (samplePos.xz - cloud_movement) / 500 ;
CloudSmall = texture2D(noisetex, SampleCoords1 ).r;
}
if(layer == 1){
SampleCoords0 = -( (samplePos.zx + cloud_movement*2) / 10000);
SampleCoords1 = -( (samplePos.zx - cloud_movement*2) / 2500);
CloudSmall = texture2D(noisetex, SampleCoords1 ).b;
}
if(layer == -1){
float otherlayer = max(pos.y - (LAYER0_minHEIGHT_FOG+99.5), 0.0) > 0 ? 0.0 : 1.0;
if(otherlayer > 0.0){
SampleCoords0 = (samplePos.xz + cloud_movement) / 5000 ;
SampleCoords1 = (samplePos.xz - cloud_movement) / 500 ;
CloudSmall = texture2D(noisetex, SampleCoords1 ).r;
}else{
SampleCoords0 = -( (samplePos.zx + cloud_movement*2) / 10000);
SampleCoords1 = -( (samplePos.zx - cloud_movement*2) / 2500);
CloudSmall = texture2D(noisetex, SampleCoords1 ).b;
}
}
float CloudLarge = texture2D(noisetex, SampleCoords0).b;
if(layer == 0){
coverage = abs(CloudLarge*2.0 - 1.2)*0.5 - (1.0-CloudSmall);
float layer0 = min(min(coverage + LAYER0_COVERAGE, clamp(LAYER0_maxHEIGHT_FOG - pos.y,0,1)), 1.0 - clamp(LAYER0_minHEIGHT_FOG - pos.y,0,1));
Topshape = max(pos.y - (LAYER0_maxHEIGHT_FOG - 75),0.0) / 200.0;
Topshape += max(pos.y - (LAYER0_maxHEIGHT_FOG - 10),0.0) / 15.0;
Baseshape = max(LAYER0_minHEIGHT_FOG + 12.5 - pos.y, 0.0) / 50.0;
FinalCloudCoverage = max(layer0 - Topshape - Baseshape * (1.0-rainStrength),0.0);
}
if(layer == 1){
coverage = abs(CloudLarge-0.8) - CloudSmall;
float layer1 = min(min(coverage + LAYER1_COVERAGE - 0.5,clamp(LAYER1_maxHEIGHT_FOG - pos.y,0,1)), 1.0 - clamp(LAYER1_minHEIGHT_FOG - pos.y,0,1));
Topshape = max(pos.y - (LAYER1_maxHEIGHT_FOG - 75),0.0) / 200.0;
Topshape += max(pos.y - (LAYER1_maxHEIGHT_FOG - 10), 0.0) / 15.0;
Baseshape = max(LAYER1_minHEIGHT_FOG + 15.5 - pos.y, 0.0) / 50.0;
FinalCloudCoverage = max(layer1 - Topshape*Topshape - Baseshape * (1.0-rainStrength), 0.0);
}
if(layer == -1){
#ifdef CloudLayer0
float layer0_coverage = abs(CloudLarge*2.0 - 1.2)*0.5 - (1.0-CloudSmall);
float layer0 = min(min(layer0_coverage + LAYER0_COVERAGE, clamp(LAYER0_maxHEIGHT_FOG - pos.y,0,1)), 1.0 - clamp(LAYER0_minHEIGHT_FOG - pos.y,0,1));
Topshape = max(pos.y - (LAYER0_maxHEIGHT_FOG - 75),0.0) / 200.0;
Topshape += max(pos.y - (LAYER0_maxHEIGHT_FOG - 10),0.0) / 15.0;
Baseshape = max(LAYER0_minHEIGHT_FOG + 12.5 - pos.y, 0.0) / 50.0;
FinalCloudCoverage = max(layer0 - Topshape - Baseshape * (1.0-rainStrength),0.0);
#endif
#ifdef CloudLayer1
float layer1_coverage = abs(CloudLarge-0.8) - CloudSmall;
float layer1 = min(min(layer1_coverage + LAYER1_COVERAGE - 0.5,clamp(LAYER1_maxHEIGHT_FOG - pos.y,0,1)), 1.0 - clamp(LAYER1_minHEIGHT_FOG - pos.y,0,1));
Topshape = max(pos.y - (LAYER1_maxHEIGHT_FOG - 75), 0.0) / 200;
Topshape += max(pos.y - (LAYER1_maxHEIGHT_FOG - 10 ), 0.0) / 50;
Baseshape = max(LAYER1_minHEIGHT_FOG + 12.5 - pos.y, 0.0) / 50.0;
FinalCloudCoverage += max(layer1 - Topshape*Topshape - Baseshape * (1.0-rainStrength), 0.0);
#endif
}
return FinalCloudCoverage;
}
//Erode cloud with 3d Perlin-worley noise, actual cloud value
float cloudVol(int layer, in vec3 pos, in vec3 samplePos, in float cov, in int LoD, float minHeight, float maxHeight){
// float curvature = 1-exp(-25*pow(clamp(1.0 - length(pos - cameraPosition)/(32*80),0.0,1.0),2));
// curvature = clamp(1.0 - length(pos - cameraPosition)/(32*128),0.0,1.0);
float otherlayer = max(pos.y - (CloudLayer0_height+99.5), 0.0) > 0 ? 0.0 : 1.0;
float upperPlane = otherlayer;
float noise = 0.0 ;
float totalWeights = 0.0;
float pw = log(fbmPower1);
float pw2 = log(fbmPower2);
samplePos.xz -= cloud_movement/4;
samplePos.xz += pow( max(pos.y - (minHeight+20), 0.0) / 20.0,1.50) ;
noise += (1.0-densityAtPos(samplePos * mix(100.0,200.0,upperPlane)) ) * sqrt(1.0-cov);
if (LoD > 0){
noise += abs( densityAtPos(samplePos * mix(450.0,600.0,upperPlane) ) - (1.0-clamp(((maxHeight - pos.y) / 100.0),0.0,1.0))) * 0.75 * (1.0-cov);
}
noise = noise*noise;
float cloud = max(cov - noise*noise*fbmAmount,0.0);
return cloud;
}
float GetCumulusDensity(int layer, in vec3 pos, in int LoD, float minHeight, float maxHeight){
vec3 samplePos = pos*vec3(1.0,1./48.,1.0)/4;
float coverageSP = cloudCov(layer, pos,samplePos, minHeight, maxHeight);
// return coverageSP;
if (coverageSP > 0.001) {
if (LoD < 0) return max(coverageSP - 0.27*fbmAmount,0.0);
return cloudVol(layer, pos,samplePos,coverageSP,LoD ,minHeight, maxHeight) ;
} else return 0.0;
}
#ifndef CLOUDSHADOWSONLY
uniform sampler2D colortex4; //Skybox
//Mie phase function
float phaseg(float x, float g){
float gg = g * g;
return (gg * -0.25 + 0.25) * pow(-2.0 * (g * x) + (gg + 1.0), -1.5) / 3.14;
}
vec3 DoCloudLighting(
float density,
vec3 skyLightCol,
float skyScatter,
float sunShadows,
vec3 sunScatter,
vec3 sunMultiScatter,
float distantfog
){
float powder = 1.0 - exp(-10.0 * density);
vec3 directLight = sunScatter * exp(-10.0 * sunShadows) + sunMultiScatter * exp(-3.0 * sunShadows) * powder;
vec3 indirectLight = skyLightCol * mix(1.0, 2.0 * (1.0 - sqrt((skyScatter*skyScatter*skyScatter)*density)) , pow(distantfog,1.0 - rainStrength*0.5));
// return directLight;
// #ifndef TEST
// return indirectLight;
// #endif
return directLight + indirectLight;
}
vec4 renderLayer(
int layer,
in vec3 POSITION,
in vec3 rayProgress,
in vec3 dV_view,
in float mult,
in float dither,
int QUALITY,
float minHeight,
float maxHeight,
in vec3 dV_Sun,
float cloudDensity,
in vec3 skyLightCol,
in vec3 sunScatter,
in vec3 sunMultiScatter,
in vec3 indirectScatter,
in float distantfog,
bool notVisible,
vec3 FragPosition,
inout vec3 cloudDepth
){
vec3 COLOR = vec3(0.0);
float TOTAL_EXTINCTION = 1.0;
bool IntersecTerrain = false;
#ifdef CLOUDS_INTERSECT_TERRAIN
// thank you emin for this world intersection thing
#if defined DISTANT_HORIZONS
float maxdist = dhRenderDistance + 16 * 32;
#else
float maxdist = far + 16*5;
#endif
float lViewPosM = length(FragPosition) < maxdist ? length(FragPosition) - 1.0 : 100000000.0;
#endif
if(layer == 2){
#ifdef CLOUDS_INTERSECT_TERRAIN
IntersecTerrain = length(rayProgress - cameraPosition) > lViewPosM;
#endif
if(notVisible || IntersecTerrain) return vec4(COLOR, TOTAL_EXTINCTION);
float signFlip = mix(-1.0, 1.0, clamp(cameraPosition.y - minHeight,0.0,1.0));
if(max(signFlip * normalize(dV_view).y,0.0) <= 0.0){
float altostratus = GetAltostratusDensity(rayProgress);
float AltoWithDensity = altostratus * cloudDensity;
if(altostratus > 1e-5){
float muE = altostratus * cloudDensity;
float directLight = 0.0;
for (int j = 0; j < 2; j++){
// lower the step size as the sun gets higher in the sky
vec3 shadowSamplePos_high = rayProgress + dV_Sun * (1.0 + j * dither) / (pow(abs(dV_Sun.y*0.5),3.0) * 0.995 + 0.005);
// lower density as the sun gets higher in the sky to simulate.... multiscattering or something idk it looks better this way
directLight += GetAltostratusDensity(shadowSamplePos_high) * cloudDensity * (1.0-abs(dV_Sun.y));
}
vec3 lighting = DoCloudLighting(AltoWithDensity, skyLightCol, 0.5, directLight, sunScatter, sunMultiScatter, distantfog);
COLOR += max(lighting - lighting*exp(-mult*muE),0.0) * TOTAL_EXTINCTION;
TOTAL_EXTINCTION *= max(exp(-mult*muE),0.0);
}
}
return vec4(COLOR, TOTAL_EXTINCTION);
}else{
#if defined CloudLayer1 && defined CloudLayer0
float upperLayerOcclusion = layer == 0 ? GetCumulusDensity(1, rayProgress + vec3(0.0,1.0,0.0) * max((LAYER1_minHEIGHT+70*dither) - rayProgress.y,0.0), 0, LAYER1_minHEIGHT, LAYER1_maxHEIGHT) : 0.0;
float skylightOcclusion = mix(1.0, (1.0 - LAYER1_DENSITY)*0.8 + 0.2, (1.0 - exp2(-5.0 * (upperLayerOcclusion*upperLayerOcclusion))) * distantfog);
#else
float skylightOcclusion = 1.0;
#endif
float expFactor = 11.0;
for(int i = 0; i < QUALITY; i++) {
#ifdef CLOUDS_INTERSECT_TERRAIN
IntersecTerrain = length(rayProgress - cameraPosition) > lViewPosM;
#endif
/// avoid overdraw
if(notVisible || IntersecTerrain) break;
// do not sample anything unless within a clouds bounding box
if(clamp(rayProgress.y - maxHeight,0.0,1.0) < 1.0 && clamp(rayProgress.y - minHeight,0.0,1.0) > 0.0){
float cumulus = GetCumulusDensity(layer, rayProgress, 1, minHeight, maxHeight);
float fadedDensity = cloudDensity * pow(clamp((rayProgress.y - minHeight)/25,0.0,1.0),2.0);
float CumulusWithDensity = cloudDensity * cumulus;
if(CumulusWithDensity > 1e-5 ){ // make sure no work is done on pixels with no densities
float muE = cumulus * fadedDensity;
float directLight = 0.0;
for (int j=0; j < 3; j++){
vec3 shadowSamplePos = rayProgress + dV_Sun * (20.0 + j * (20.0 + dither*20.0));
directLight += GetCumulusDensity(layer, shadowSamplePos, 0, minHeight, maxHeight) * cloudDensity;
}
/// shadows cast from one layer to another
/// large cumulus -> small cumulus
#if defined CloudLayer1 && defined CloudLayer0
if(layer == 0) directLight += LAYER1_DENSITY * 2.0 * GetCumulusDensity(1, rayProgress + dV_Sun/abs(dV_Sun.y) * max((LAYER1_minHEIGHT+70*dither) - rayProgress.y,0.0), 0, LAYER1_minHEIGHT, LAYER1_maxHEIGHT);
#endif
// altostratus -> cumulus
#ifdef CloudLayer2
vec3 HighAlt_shadowPos = rayProgress + dV_Sun/abs(dV_Sun.y) * max(LAYER2_HEIGHT - rayProgress.y,0.0);
float HighAlt_shadow = GetAltostratusDensity(HighAlt_shadowPos) * CloudLayer2_density * (1.0-abs(WsunVec.y));
directLight += HighAlt_shadow;
#endif
float skyScatter = clamp(((maxHeight - rayProgress.y) / 100.0),0.0,1.0); // linear gradient from bottom to top of cloud layer
vec3 lighting = DoCloudLighting(CumulusWithDensity, skyLightCol * skylightOcclusion, skyScatter, directLight, sunScatter, sunMultiScatter, distantfog);
COLOR += max(lighting - lighting*exp(-mult*muE),0.0) * TOTAL_EXTINCTION;
TOTAL_EXTINCTION *= max(exp(-mult*muE),0.0);
if (TOTAL_EXTINCTION < 1e-5) break;
}
}
rayProgress += dV_view;
}
return vec4(COLOR, TOTAL_EXTINCTION);
}
}
vec3 layerStartingPosition(
vec3 dV_view,
vec3 cameraPos,
float dither,
float minHeight,
float maxHeight
){
// allow passing through/above/below the plane without limits
float flip = mix(max(cameraPos.y - maxHeight,0.0), max(minHeight - cameraPos.y,0.0), clamp(dV_view.y,0.0,1.0));
// orient the ray to be a flat plane facing up/down
vec3 position = dV_view*dither + cameraPos + (dV_view/abs(dV_view.y)) * flip;
return position;
}
float invLinZ_cloud (float lindepth){
return -((2.0*near/lindepth)-far-near)/(far-near);
}
vec4 renderClouds(
vec3 FragPosition,
vec2 Dither,
vec3 LightColor,
vec3 SkyColor,
inout vec3 cloudDepth
){
vec3 SignedWsunvec = WsunVec;
vec3 WsunVec = WsunVec * (float(sunElevation > 1e-5)*2.0-1.0);
#ifndef VOLUMETRIC_CLOUDS
return vec4(0.0,0.0,0.0,1.0);
#endif
float total_extinction = 1.0;
vec3 color = vec3(0.0);
float heightRelativeToClouds = clamp(1.0 - max(cameraPosition.y - LAYER0_minHEIGHT,0.0) / 100.0 ,0.0,1.0);
//////////////////////////////////////////
////// Raymarching stuff
//////////////////////////////////////////
//project pixel position into projected shadowmap space
vec4 viewPos = normalize(gbufferModelViewInverse * vec4(FragPosition,1.0) );
maxIT_clouds = int(clamp(maxIT_clouds / sqrt(exp2(viewPos.y)),0.0, maxIT));
// maxIT_clouds = 30;
vec3 dV_view = normalize(viewPos.xyz);
// this is the cloud curvature.
dV_view.y += 0.025 * heightRelativeToClouds;
vec3 dV_view_Alto = dV_view;
dV_view_Alto *= 5.0/abs(dV_view_Alto.y);
float mult_alto = length(dV_view_Alto);
// dV_view *= (LAYER0_maxHEIGHT - LAYER0_minHEIGHT)/abs(dV_view.y)/maxIT_clouds;
vec3 dV_viewTEST = dV_view * (90.0/abs(dV_view.y)/maxIT_clouds);
float mult = length(dV_viewTEST);
//////////////////////////////////////////
////// lighting stuff
//////////////////////////////////////////
vec3 dV_Sun = WsunVec;
#ifdef EXCLUDE_WRITE_TO_LUT
dV_Sun *= lightCol.a;
#endif
float SdotV = dot(WsunVec, normalize(mat3(gbufferModelViewInverse)*FragPosition + gbufferModelViewInverse[3].xyz));
float mieDay = phaseg(SdotV, 0.85) + phaseg(SdotV, 0.75);
float mieDayMulti = (phaseg(SdotV, 0.35) + phaseg(-SdotV, 0.35) * 0.5) ;
vec3 directScattering = LightColor * mieDay * 3.14 ;
vec3 directMultiScattering = LightColor * mieDayMulti * 3.14 * 2.0;
vec3 sunIndirectScattering = LightColor;// * phaseg(dot(mat3(gbufferModelView)*vec3(0,1,0),normalize(FragPosition)), 0.5) * 3.14;
// use this to blend into the atmosphere's ground.
vec3 approxdistance = normalize(dV_viewTEST);
#ifdef SKY_GROUND
float distantfog = mix(1.0, max(1.0 - clamp(exp2(pow(abs(approxdistance.y),mix(1.5, 4.0, rainStrength)) * -mix(100.0, 35.0, rainStrength)),0.0,1.0),0.0), heightRelativeToClouds);
#else
float distantfog = 1.0;
float distantfog2 = mix(1.0, max(1.0 - clamp(exp(pow(abs(approxdistance.y),1.5) * -35.0),0.0,1.0),0.0), heightRelativeToClouds);
#endif
// terrible fake rayleigh scattering
vec3 rC = vec3(sky_coefficientRayleighR*1e-6, sky_coefficientRayleighG*1e-5, sky_coefficientRayleighB*1e-5)*3.0;
float atmosphere = exp(abs(approxdistance.y) * -5.0);
vec3 scatter = distantfog * exp(-10000.0 * rC * atmosphere);
directScattering *= scatter;
directMultiScattering *= scatter;
SkyColor *= mix(1.0* Sky_Brightness, 1.0-pow(1.0-clamp(SignedWsunvec.y,0.0,1.0),5.0) * 0.75 + 0.25, distantfog);
//////////////////////////////////////////
////// render Cloud layers and do blending orders
//////////////////////////////////////////
// first cloud layer
float MinHeight = LAYER0_minHEIGHT;
float MaxHeight = LAYER0_maxHEIGHT;
float MinHeight1 = LAYER1_minHEIGHT;
float MaxHeight1 = LAYER1_maxHEIGHT;
float Height2 = LAYER2_HEIGHT;
// int above_Layer0 = int(clamp(cameraPosition.y - MaxHeight,0.0,1.0));
int below_Layer0 = int(clamp(MaxHeight - cameraPosition.y,0.0,1.0));
int above_Layer1 = int(clamp(MaxHeight1 - cameraPosition.y,0.0,1.0));
bool below_Layer1 = clamp(cameraPosition.y - MinHeight1,0.0,1.0) < 1.0;
bool below_Layer2 = clamp(cameraPosition.y - Height2,0.0,1.0) < 1.0;
// bool layer1_below_layer0 = MinHeight1 < MinHeight;
bool altoNotVisible = false;
#ifdef CloudLayer0
vec3 layer0_dV_view = dV_view * (LAYER0_width/abs(dV_view.y)/maxIT_clouds);
vec3 layer0_start = layerStartingPosition(layer0_dV_view, cameraPosition, Dither.y, MinHeight, MaxHeight);
#endif
#ifdef CloudLayer1
vec3 layer1_dV_view = dV_view * (LAYER1_width/abs(dV_view.y)/maxIT_clouds);
vec3 layer1_start = layerStartingPosition(layer1_dV_view, cameraPosition, Dither.y, MinHeight1, MaxHeight1);
#endif
#ifdef CloudLayer2
vec3 layer2_start = layerStartingPosition(dV_view_Alto, cameraPosition, Dither.y, Height2, Height2);
#endif
#ifdef CloudLayer0
vec4 layer0 = renderLayer(0,dV_view, layer0_start, layer0_dV_view, mult, Dither.x, maxIT_clouds, MinHeight, MaxHeight, dV_Sun, LAYER0_DENSITY, SkyColor, directScattering, directMultiScattering, sunIndirectScattering, distantfog, false, FragPosition, cloudDepth);
total_extinction *= layer0.a;
// stop overdraw.
bool notVisible = layer0.a < 1e-5 && below_Layer1;
altoNotVisible = notVisible;
#else
// stop overdraw.
bool notVisible = false;
#endif
#ifdef CloudLayer1
vec4 layer1 = renderLayer(1,dV_view, layer1_start, layer1_dV_view, mult, Dither.x, maxIT_clouds, MinHeight1, MaxHeight1, dV_Sun, LAYER1_DENSITY, SkyColor, directScattering, directMultiScattering, sunIndirectScattering, distantfog, notVisible, FragPosition, cloudDepth);
total_extinction *= layer1.a;
// stop overdraw.
altoNotVisible = (layer1.a < 1e-5 || notVisible) && below_Layer1;
#endif
#ifdef CloudLayer2
vec4 layer2 = renderLayer(2,dV_view,layer2_start, dV_view_Alto, mult_alto, Dither.x, maxIT_clouds, Height2, Height2, dV_Sun, LAYER2_DENSITY, SkyColor, directScattering * (1.0 + rainStrength*3), directMultiScattering* (1.0 + rainStrength*3), sunIndirectScattering, distantfog, altoNotVisible, FragPosition, cloudDepth);
total_extinction *= layer2.a;
#endif
/// i know this looks confusing
/// it is changing blending order based on the players position relative to the clouds.
/// to keep it simple for myself, it all revolves around layer0, the lowest cloud layer.
/// for layer1, swap between back to front and front to back blending if you are above or below layer0
/// for layer2, swap between back to front and front to back blending if you are above or below layer1
/// blend the altostratus clouds first, so it is BEHIND all the cumulus clouds, if the player postion is below the cumulus clouds.
/// handle the case if one of the cloud layers is disabled.
#if !defined CloudLayer1 && defined CloudLayer2
if(below_Layer2) color = color * layer2.a + layer2.rgb;
#endif
#if defined CloudLayer1 && defined CloudLayer2
if(below_Layer2) layer1.rgb = layer2.rgb * layer1.a + layer1.rgb;
#endif
/// blend the cumulus clouds together. swap the blending order from (BACK TO FRONT -> FRONT TO BACK) depending on the player position relative to the lowest cloud layer.
#if defined CloudLayer0 && defined CloudLayer1
color = mix(layer0.rgb, layer1.rgb, float(below_Layer0));
color = mix(color * layer1.a + layer1.rgb, color * layer0.a + layer0.rgb, float(below_Layer0));
#endif
/// handle the case of one of the cloud layers being disabled.
#if defined CloudLayer0 && !defined CloudLayer1
color = color * layer0.a + layer0.rgb;
#endif
#if !defined CloudLayer0 && defined CloudLayer1
color = color * layer1.a + layer1.rgb;
#endif
/// blend the altostratus clouds last, so it is IN FRONT of all the cumulus clouds when the player position is above them.
#ifdef CloudLayer2
if(!below_Layer2) color = color * layer2.a + layer2.rgb;
#endif
#ifndef SKY_GROUND
// return mix(fogcolor, vec4(color, total_extinction), clamp(distantfog2,0.0,1.0));
return mix(vec4(vec3(0.0),1.0), vec4(color, total_extinction), clamp(distantfog2,0.0,1.0));
#else
return vec4(color, total_extinction);
#endif
}
#endif
float GetCloudShadow(vec3 feetPlayerPos){
#ifdef CLOUDS_SHADOWS
vec3 playerPos = feetPlayerPos + cameraPosition;
float shadow = 0.0;
// assume a flat layer of cloud, and stretch the sampled density along the sunvector, starting from some vertical layer in the cloud.
#ifdef CloudLayer0
vec3 lowShadowStart = playerPos + (WsunVec / max(abs(WsunVec.y),0.0)) * max((CloudLayer0_height + 30) - playerPos.y,0.0) ;
shadow += GetCumulusDensity(0, lowShadowStart, 0, CloudLayer0_height, CloudLayer0_height+100)*LAYER0_DENSITY;
#endif
#ifdef CloudLayer1
vec3 higherShadowStart = playerPos + (WsunVec / max(abs(WsunVec.y),0.0)) * max((CloudLayer1_height + 50) - playerPos.y,0.0) ;
shadow += GetCumulusDensity(1, higherShadowStart, 0, CloudLayer1_height, CloudLayer1_height+100)*LAYER1_DENSITY;
#endif
#ifdef CloudLayer2
vec3 highShadowStart = playerPos + (WsunVec / max(abs(WsunVec.y),0.0)) * max(CloudLayer2_height - playerPos.y,0.0);
shadow += GetAltostratusDensity(highShadowStart) * CloudLayer2_density * (1.0-abs(WsunVec.y));
#endif
shadow = clamp(shadow,0.0,1.0);
shadow = exp2((shadow*shadow) * -100.0);
return mix(1.0, shadow, CLOUD_SHADOW_STRENGTH);
#else
return 1.0;
#endif
}
float GetCloudShadow_VLFOG(vec3 WorldPos, vec3 WorldSpace_sunVec){
#ifdef CLOUDS_SHADOWS
float shadow = 0.0;
#ifdef CloudLayer0
vec3 lowShadowStart = WorldPos + (WorldSpace_sunVec / max(abs(WorldSpace_sunVec.y),0.0)) * max((CloudLayer0_height + 30) - WorldPos.y,0.0) ;
shadow += max(GetCumulusDensity(0, lowShadowStart, 0, CloudLayer0_height, CloudLayer0_height+100),0.0)*LAYER0_DENSITY;
#endif
#ifdef CloudLayer1
vec3 higherShadowStart = WorldPos + (WorldSpace_sunVec / max(abs(WorldSpace_sunVec.y),0.0)) * max((CloudLayer1_height + 30) - WorldPos.y,0.0) ;
shadow += max(GetCumulusDensity(1,higherShadowStart, 0, CloudLayer1_height,CloudLayer1_height+100) ,0.0)*LAYER1_DENSITY;
#endif
#ifdef CloudLayer2
vec3 highShadowStart = WorldPos + (WorldSpace_sunVec / max(abs(WorldSpace_sunVec.y),0.0)) * max(CloudLayer2_height - WorldPos.y,0.0);
shadow += GetAltostratusDensity(highShadowStart)*LAYER2_DENSITY * (1.0-abs(WorldSpace_sunVec.y));
#endif
shadow = clamp(shadow,0.0,1.0);
shadow = exp((shadow*shadow) * -100.0);
return mix(1.0, shadow, CLOUD_SHADOW_STRENGTH);
#else
return 1.0;
#endif
}