/********************************************************************************/ /* */ /* Noble Shaders */ /* Copyright (C) 2026 Belmu */ /* */ /* This program is free software: you can redistribute it and/or modify */ /* it under the terms of the GNU General Public License as published by */ /* the Free Software Foundation, either version 3 of the License, or */ /* (at your option) any later version. */ /* */ /* This program is distributed in the hope that it will be useful, */ /* but WITHOUT ANY WARRANTY; without even the implied warranty of */ /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */ /* GNU General Public License for more details. */ /* */ /* You should have received a copy of the GNU General Public License */ /* along with this program. If not, see . */ /* */ /********************************************************************************/ float dither = temporalBlueNoise(gl_FragCoord.xy); const float aerialPerspectiveMult = 1.0; #if defined WORLD_OVERWORLD const vec3 sandFogExtinctionCoefficients = vec3(0.24, 0.28, 0.36); const vec3 sandFogScatteringCoefficients = vec3(0.80, 0.55, 0.36); vec3 airFogAttenuationCoefficients = mix(vec3(airFogExtinctionCoefficient), sandFogExtinctionCoefficients, biome_may_sandstorm); vec3 airFogScatteringCoefficients = mix(vec3(airFogScatteringCoefficient), sandFogScatteringCoefficients, biome_may_sandstorm); const float fogAltitude = FOG_ALTITUDE; const float fogThickness = FOG_THICKNESS; float fogFrequency = mix(0.7, 1.0, biome_may_sandstorm); vec2 fogShapeFactors = mix(vec2(1.5, 0.4), vec2(2.0, 0.4), biome_may_sandstorm); float densityFactor = wetness; float densityMult = mix(0.1, 0.7, biome_may_sandstorm); #elif defined WORLD_NETHER const vec3 airFogAttenuationCoefficients = vec3(0.02, 0.03, 0.30); const vec3 airFogScatteringCoefficients = vec3(0.20, 0.10, 0.06); const float fogAltitude = max(0.0, FOG_ALTITUDE - 63.0); const float fogThickness = FOG_THICKNESS * 2.0; const float fogFrequency = 0.7; const vec2 fogShapeFactors = vec2(2.0, 0.7); const float densityFactor = 1.0; const float densityMult = 0.03; #elif defined WORLD_END float airFogTransitionFactor = sin(frameTimeCounter * 2.0); vec3 airFogAttenuationCoefficients = mix(vec3(0.30, 0.20, 0.30), vec3(0.10, 0.05, 0.10), airFogTransitionFactor); vec3 airFogScatteringCoefficients = mix(vec3(0.80, 0.70, 0.80), vec3(1.00, 1.00, 1.00), airFogTransitionFactor); const float fogAltitude = max(0.0, FOG_ALTITUDE - 63.0); const float fogThickness = min(200.0, (FOG_THICKNESS + 40.0) * 2.0); const float fogFrequency = 0.7; const vec2 fogShapeFactors = vec2(2.0, 0.7); const float densityFactor = 1.0; const float densityMult = 1.0; #endif float fogDensity = saturate(FOG_DENSITY + densityFactor) * 0.4; uniform ivec2 eyeBrightness; uniform ivec2 eyeBrightnessSmooth; uniform float rcp240; float calculateAirFogPhase(float cosTheta) { float forwardsLobe = henyeyGreensteinPhase(cosTheta, airFogForwardsLobe); float backwardsLobe = henyeyGreensteinPhase(cosTheta,-airFogBackardsLobe); float forwardsPeak = kleinNishinaPhase (cosTheta, airFogForwardsPeak); return mix(mix(forwardsLobe, backwardsLobe, airFogBackScatter), forwardsPeak, airFogPeakWeight); } #if AIR_FOG == 2 void computeAirFogApproximation( out vec3 scatteringOut, out vec3 transmittanceOut, vec3 viewPosition, float farPlane, float VdotL, vec3 directIlluminance, vec3 skyIlluminance, float skylight ) { float airmassFog = quinticStep(0.0, far, length(viewPosition.xz)) * fogDensity * densityMult; vec3 transmittanceFog = exp(-airFogAttenuationCoefficients * airmassFog * 10.0); vec3 scatteringFog = skyIlluminance * isotropicPhase * skylight; scatteringFog += directIlluminance * calculateAirFogPhase(VdotL); scatteringFog *= airFogScatteringCoefficients * ((1.0 - transmittanceFog) / airFogAttenuationCoefficients); vec3 scatteringAerial = vec3(0.0); vec3 transmittanceAerial = vec3(1.0); #if defined WORLD_OVERWORLD && AERIAL_PERSPECTIVE == 1 float airmassAerial = quinticStep(0.0, farPlane, length(viewPosition.xz)) * aerialPerspectiveMult * AERIAL_PERSPECTIVE_DENSITY; vec3 opticalDepthAerial = atmosphereAttenuationCoefficients * vec3(airmassAerial); transmittanceAerial = exp(-opticalDepthAerial); vec2 phaseAerial = vec2(rayleighPhase(VdotL), kleinNishinaPhase(VdotL, mieAnisotropyFactor)); vec3 visibleScatteringAerial = saturate((transmittanceAerial - 1.0) / -opticalDepthAerial); scatteringAerial = atmosphereScatteringCoefficients * vec2(phaseAerial * airmassAerial) * visibleScatteringAerial; scatteringAerial *= directIlluminance * skyIlluminance * eyeBrightness.y * rcp240; #endif scatteringOut = scatteringFog + scatteringAerial; transmittanceOut = transmittanceFog * transmittanceAerial; } #elif AIR_FOG == 1 uniform sampler3D depthtex2; float getAirFogDensity(vec3 position) { if (clamp(position.y, fogAltitude, fogAltitude + fogThickness) != position.y) return 0.0; float altitude = (position.y - fogAltitude) * rcp(fogThickness); float shapeAlter = remap(altitude, 0.0, 0.2, 0.0, 1.0) * remap(altitude, 0.9, 1.0, 1.0, 0.0); #if defined WORLD_END float movementSpeed = frameTimeCounter * 10.0; position.y -= 60.0; position.xz = -position.xz; position = rotate(position, vec3(0.0, 1.0, 0.0), starVector); position = rotate(position, vec3(0.0, 1.0, 0.0), movementSpeed); position.xz = -position.xz; position.y -= movementSpeed; #endif #if defined WORLD_NETHER //fogShapeFactors = mix(vec2(2.5, 0.6), fogShapeFactors, sqrt(quinticStep(0.0, 1.0, min(125.0, position.y) / 125.0))); #endif vec4 shapeTex = texture(depthtex2, position * FOG_SHAPE_SCALE * km_to_m); float shapeNoise = remap(pow(shapeTex.r, 1.4), -(1.0 - (shapeTex.g * 0.625 + shapeTex.b * 0.25 + shapeTex.a * 0.125)), 1.0, 0.0, 1.0); shapeNoise = (shapeNoise * shapeAlter - (2.0 * shapeAlter * altitude * 0.5 + 0.5)) * fogShapeFactors.x - fogShapeFactors.y; #if defined WORLD_OVERWORLD shapeNoise *= exp(-abs(position.y - fogAltitude) * 0.14); #elif defined WORLD_NETHER //fogDensity *= mix(1.2, 1.0, sqrt(quinticStep(0.0, 1.0, min(125.0, position.y) / 125.0))); #elif defined WORLD_END float innerRadius = 30.0; float outerRingStart = 70.0; float outerRingEnd = 160.0; float distanceFromCenter = length(position.xz); float fogFalloff = quinticStep(innerRadius, outerRingStart, distanceFromCenter) * pow2(quinticStep(outerRingEnd, outerRingStart, distanceFromCenter)) * exp(-rcp(distanceFromCenter)); shapeNoise *= fogFalloff; #endif return saturate(shapeNoise) * fogDensity * densityMult; } float getFogTransmittance(vec3 rayOrigin, vec3 lightDir) { const float stepSize = 1.0 / AIR_FOG_TRANSMITTANCE_STEPS; vec3 increment = lightDir * stepSize; vec3 rayPosition = rayOrigin + increment * 0.5; float accumAirmass = 0.0; for (int i = 0; i < AIR_FOG_TRANSMITTANCE_STEPS; i++, rayPosition += increment) { accumAirmass += getAirFogDensity(rayPosition) * stepSize; } return exp(-airFogExtinctionCoefficient * accumAirmass); } void computeVolumetricAirFog( inout vec3 scatteringOut, inout vec3 transmittanceOut, vec3 startPosition, vec3 endPosition, vec3 viewPosition, float farPlane, float VdotL, vec3 directIlluminance, vec3 skyIlluminance, bool sky ) { #if defined WORLD_NETHER && NETHER_FOG == 0 return; #endif #if defined WORLD_END && END_FOG == 0 return; #endif const float stepSize = 1.0 / AIR_FOG_SCATTERING_STEPS; vec3 increment = (endPosition - startPosition) * stepSize; vec3 rayPosition = startPosition + increment * dither; rayPosition += cameraPosition; vec3 shadowStartPosition = worldToShadowClip(startPosition); vec3 shadowIncrement = (worldToShadowClip(endPosition) - shadowStartPosition) * stepSize; vec3 shadowPosition = shadowStartPosition + shadowIncrement * dither; float rayLength = length(increment); float phaseFog = calculateAirFogPhase(VdotL); vec2 phaseAerial = vec2(rayleighPhase(VdotL), kleinNishinaPhase(VdotL, mieAnisotropyFactor)); float distanceFalloffAerial = linearStep(0.0, farPlane, length(endPosition.xz)); vec3 shadow = vec3(1.0); for (uint i = 0u; i < AIR_FOG_SCATTERING_STEPS; i++, rayPosition += increment, shadowPosition += shadowIncrement) { // Early exit if transmittance is too low if (maxOf(transmittanceOut) < EPS) break; #if defined WORLD_OVERWORLD if ((i & 3u) == 0u) { shadow = getShadowColor(shadowClipToShadowScreen(shadowPosition)); } #if CLOUDS_SHADOWS == 1 && CLOUDS_LAYER0_ENABLED == 1 shadow *= getCloudsShadows(rayPosition); #endif #endif float densityFog = 0.0; if (fogDensity > 1e-2) { float distanceFalloffFog = quinticStep(0.0, 1.0, exp2(-1.0 * length(rayPosition - cameraPosition) / farPlane)); densityFog = getAirFogDensity(rayPosition) * distanceFalloffFog; } vec3 stepScatteringDirect = vec3(0.0); vec3 stepScatteringIndirect = vec3(0.0); vec3 stepTransmittance = vec3(1.0); if (densityFog > 1e-2) { float airmassFog = densityFog * rayLength; vec3 opticalDepthFog = airFogAttenuationCoefficients * airmassFog; vec3 stepTransmittanceFog = exp(-opticalDepthFog); vec3 visibleScatteringFog = transmittanceOut * saturate((stepTransmittanceFog - 1.0) / -opticalDepthFog); stepScatteringDirect += airFogScatteringCoefficients * airmassFog * phaseFog * directIlluminance * visibleScatteringFog * shadow; stepScatteringIndirect += airFogScatteringCoefficients * airmassFog * isotropicPhase * skyIlluminance * visibleScatteringFog; stepTransmittance *= stepTransmittanceFog; } #if defined WORLD_OVERWORLD && AERIAL_PERSPECTIVE == 1 float heightFalloffAerial = exp(-max0(rayPosition.y - cameraPosition.y) * 0.08) * float(!sky); float airmassAerial = rayLength * heightFalloffAerial * distanceFalloffAerial * AERIAL_PERSPECTIVE_DENSITY * 20.0; vec3 opticalDepthAerial = atmosphereAttenuationCoefficients * vec3(airmassAerial); vec3 stepTransmittanceAerial = exp(-opticalDepthAerial); vec3 visibleScatteringAerial = transmittanceOut * saturate((stepTransmittanceAerial - 1.0) / -opticalDepthAerial); stepScatteringDirect += atmosphereScatteringCoefficients * vec2(phaseAerial * airmassAerial) * directIlluminance * visibleScatteringAerial * shadow; stepScatteringIndirect += atmosphereScatteringCoefficients * vec2(isotropicPhase * airmassAerial) * skyIlluminance * visibleScatteringAerial; stepTransmittance *= stepTransmittanceAerial; #endif #if defined WORLD_OVERWORLD stepScatteringIndirect *= eyeBrightness.y * rcp240; #endif scatteringOut += stepScatteringDirect + stepScatteringIndirect; transmittanceOut *= stepTransmittance; } } #endif #if TONEMAP == ACES const vec3 waterAbsorptionCoefficients = (vec3(WATER_ABSORPTION_R, WATER_ABSORPTION_G, WATER_ABSORPTION_B) * 0.01) * SRGB_2_AP1_ALBEDO; const vec3 waterScatteringCoefficients = (vec3(WATER_SCATTERING_R, WATER_SCATTERING_G, WATER_SCATTERING_B) * 0.01) * SRGB_2_AP1_ALBEDO; #else const vec3 waterAbsorptionCoefficients = vec3(WATER_ABSORPTION_R, WATER_ABSORPTION_G, WATER_ABSORPTION_B) * 0.01; const vec3 waterScatteringCoefficients = vec3(WATER_SCATTERING_R, WATER_SCATTERING_G, WATER_SCATTERING_B) * 0.01; #endif vec3 waterExtinctionCoefficients = saturate(waterScatteringCoefficients + waterAbsorptionCoefficients); #if WATER_FOG == 0 void computeWaterFogApproximation( out vec3 scatteringOut, out vec3 transmittanceOut, vec3 startPosition, vec3 endPosition, float VdotL, vec3 directIlluminance, vec3 skyIlluminance, float skylight ) { transmittanceOut = exp(-waterAbsorptionCoefficients * distance(startPosition, endPosition)); scatteringOut = skyIlluminance * isotropicPhase * skylight; scatteringOut += directIlluminance * kleinNishinaPhase(VdotL, 0.5); scatteringOut *= waterScatteringCoefficients * (1.0 - transmittanceOut) / waterAbsorptionCoefficients; } #else void computeVolumetricWaterFog( out vec3 scatteringOut, out vec3 transmittanceOut, vec3 startPosition, vec3 endPosition, float farPlane, float VdotL, vec3 directIlluminance, vec3 skyIlluminance, float skylight, bool sky ) { const float stepSize = 1.0 / WATER_FOG_STEPS; vec3 worldIncrement = (endPosition - startPosition) * stepSize; vec3 worldPosition = startPosition + worldIncrement * dither; worldPosition += cameraPosition; vec3 shadowIncrement = mat3(shadowModelView) * worldIncrement; shadowIncrement = diagonal3(shadowProjection) * shadowIncrement; vec3 shadowPosition = worldToShadowClip(worldPosition - cameraPosition); float rayLength = sky ? farPlane : length(worldIncrement); float eyeSkylight = saturate(eyeBrightnessSmooth.y * rcp240); float phase = henyeyGreensteinPhase(VdotL, 0.5); vec3 stepTransmittance = exp(-waterExtinctionCoefficients * rayLength); vec3 scattering = vec3(0.0); vec3 transmittance = vec3(1.0); vec3 shadow = vec3(1.0); for (uint i = 0u; i < WATER_FOG_STEPS; i++, worldPosition += worldIncrement, shadowPosition += shadowIncrement) { // Early exit if transmittance is too low if (maxOf(transmittanceOut) < EPS) break; vec3 shadowScreenPosition = shadowClipToShadowScreen(shadowPosition); float shadowDepth0 = texture(shadowtex0, shadowScreenPosition.xy).r; if ((i & 3u) == 0u) { shadow = getShadowColor(shadowScreenPosition); } float distanceThroughWater = abs(shadowDepth0 - shadowScreenPosition.z) * -shadowProjectionInverse[2].z / SHADOW_DEPTH_STRETCH; #if CLOUDS_SHADOWS == 1 && CLOUDS_LAYER0_ENABLED == 1 shadow *= getCloudsShadows(worldPosition); #endif vec3 directTransmittance = shadow * exp(-waterExtinctionCoefficients * distanceThroughWater); scattering += transmittance * directIlluminance * phase * directTransmittance; scattering += transmittance * skyIlluminance * isotropicPhase * eyeSkylight; transmittance *= stepTransmittance; } vec3 scatteringAlbedo = saturate(waterScatteringCoefficients / waterExtinctionCoefficients); scattering *= (1.0 - stepTransmittance) * scatteringAlbedo; // Multiple scattering approximation provided by Jessie vec3 multipleScatteringFactor = scatteringAlbedo * 0.84; int phaseSampleCount = 16; float phaseMultiple = 0.0; for (int i = 0; i < phaseSampleCount; i++) { phaseMultiple += cornetteShanksPhase(VdotL, 0.6 * pow(0.5, phaseSampleCount)); } phaseMultiple /= phaseSampleCount; scatteringOut = scattering * phaseMultiple; scatteringOut *= multipleScatteringFactor / (1.0 - multipleScatteringFactor); transmittanceOut = transmittance; } #endif