fix:代码提初始化

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zhangjiajia
2026-05-08 15:34:53 +08:00
parent af67dcce8c
commit 2540141343
4131 changed files with 1239331 additions and 0 deletions

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@@ -0,0 +1,883 @@
#ifndef PI
#define PI 3.14159265
#endif
#ifndef TWO_PI
#define TWO_PI 6.28318530
#endif
#ifndef INV_PI
#define INV_PI 0.31830989
#endif
uniform Texture3D _Noise;
SamplerState sampler_Noise;
uniform Texture3D _DetailNoise;
SamplerState sampler_DetailNoise;
uniform Texture2D _WeatherMap;
SamplerState sampler_WeatherMap;
uniform Texture2D _CurlNoise;
SamplerState sampler_CurlNoise;
uniform sampler2D _BottomsOffsetNoise;
uniform sampler2D _BlueNoise;
float4 _BlueNoise_TexelSize;
float3 _WorldOffset;
uniform float4x4 _InverseProjection;
uniform float4x4 _InverseRotation;
uniform float4x4 _InverseProjectionRight;
uniform float4x4 _InverseRotationRight;
float4x4 _LeftWorldFromView;
float4x4 _RightWorldFromView;
float4x4 _LeftViewFromScreen;
float4x4 _RightViewFromScreen;
uniform float4 _CloudsParameter;
uniform float4 _CloudsParameter2;
uniform float4 _Steps;
uniform float4 _CloudsLighting;
uniform float4 _CloudsLighting2;
uniform float4 _CloudsLightingExtended;
uniform float4 _CloudsLightingExtended2;
uniform float4 _CloudsMultiScattering;
uniform float4 _CloudsMultiScattering2;
uniform float4 _CloudsErosionIntensity; //x = Base, y = Detail
uniform float4 _CloudsNoiseSettings; //x = Base, y = Detail
uniform float4 _CloudsShape1;
uniform float4 _CloudsShape2;
uniform float4 _CloudDensityScale;
uniform float4 _CloudsCoverageSettings; //x = _GlobalCoverage, y = Bottom Coverage Mod, z = Top coverage mod, w = Clouds Up Morph Intensity
uniform float _GlobalCoverage;
uniform float4 _CloudsAnimation;
uniform float4 _CloudsWindDirection;
uniform float3 _LightDir;
uniform float _stepsInDepth;
uniform float _LODDistance;
uniform float3 _CameraPosition;
uniform float4 _Resolution;
uniform float4 _Randomness;
uniform float _EnviroDepthTest;
uniform float _SolarTime;
////
const float env_inf = 1e10;
struct RaymarchParameters
{
//Lighting
float scatteringCoef;
float silverLiningIntensity;
float silverLiningSpread;
float edgeHighlightStrength;
float directIndirectBalance;
float exposure;
float attenuation;
float lightStep;
float lightAbsorb;
float multiScatterStrength;
float multiScatterFalloff;
float ambientFloor;
//Height
float4 cloudsParameter;
//Density
float density;
float densitySmoothness;
//Erosion
float baseErosion;
float detailErosion;
int minSteps, maxSteps;
float baseNoiseUV;
float detailNoiseUV;
float baseErosionIntensity;
float detailErosionIntensity;
float baseNoiseMultiplier;
float detailNoiseMultiplier;
float bottomShape;
float midShape;
float topShape;
float topLayer;
float rampShape;
float cloudTypeShaping;
};
void InitRaymarchParameters(inout RaymarchParameters parameters)
{
parameters.scatteringCoef = _CloudsLighting.x;
parameters.silverLiningIntensity = _CloudsLighting.y;
parameters.silverLiningSpread = _CloudsLighting.w;
parameters.multiScatterStrength = _CloudsMultiScattering.x;
parameters.multiScatterFalloff = _CloudsMultiScattering.y;
parameters.ambientFloor = _CloudsMultiScattering.z;
parameters.exposure = _CloudsMultiScattering.w;
parameters.directIndirectBalance = _CloudsLightingExtended.x;
parameters.attenuation = _CloudsLightingExtended.y;
parameters.lightStep = _CloudsLightingExtended.z;
parameters.lightAbsorb = _CloudsLightingExtended.w;
parameters.edgeHighlightStrength = _CloudsLighting.z;
parameters.cloudsParameter = _CloudsParameter;
parameters.density = _CloudDensityScale.x;
parameters.densitySmoothness = _CloudDensityScale.z;
parameters.baseErosion = _CloudsErosionIntensity.x;
parameters.detailErosion = _CloudsErosionIntensity.y;
parameters.baseNoiseMultiplier = _CloudsNoiseSettings.z;
parameters.detailNoiseMultiplier = _CloudsNoiseSettings.w;
parameters.minSteps = _Steps.x;
parameters.maxSteps = _Steps.y;
parameters.baseNoiseUV = _CloudsNoiseSettings.x;
parameters.detailNoiseUV = _CloudsNoiseSettings.y;
parameters.baseErosionIntensity = _CloudsErosionIntensity.x;
parameters.detailErosionIntensity = _CloudsErosionIntensity.y;
parameters.bottomShape = _CloudsShape1.x;
parameters.midShape = _CloudsShape1.y;
parameters.topShape = _CloudsShape1.z;
parameters.topLayer = _CloudsShape1.w;
parameters.rampShape = _CloudsCoverageSettings.w;
parameters.cloudTypeShaping = _CloudsCoverageSettings.z;
}
float HenryGreensteinNorm(float cosTheta, float g)
{
float g2 = g * g;
return (1.0 - g2) / (4.0 * PI * pow(1.0 + g2 - 2.0 * g * cosTheta, 1.5));
}
float RemapEnviro(float org_val, float org_min, float org_max, float new_min, float new_max)
{
return new_min + saturate(((org_val - org_min) / (org_max - org_min))*(new_max - new_min));
}
float4 GetWeather(float3 pos)
{
float2 uv = pos.xz * 0.0000025;
return _WeatherMap.SampleLevel(sampler_WeatherMap,uv, 0);
}
float GetSamplingHeight(float3 pos, float3 center, float4 parameters)
{
return (length(pos - center) - (parameters.w + parameters.x)) * parameters.z;
}
float3 ScreenSpaceDither(float2 vScreenPos, float lum)
{
float d = dot(float2(131.0, 312.0), vScreenPos.xy); //+ _Time TODO
float3 vDither = float3(d, d, d);
vDither.rgb = frac(vDither.rgb / float3(103.0, 71.0, 97.0)) - float3(0.5, 0.5, 0.5);
return (vDither.rgb / 15.0) * 1.0 * lum;
}
float GetRaymarchEndFromSceneDepth(float sceneDepth, float maxRange)
{
float raymarchEnd = 0.0f;
#if ENVIRO_DEPTH_BLENDING
if (sceneDepth >= 0.99f)
{
raymarchEnd = maxRange;
}
else
{
raymarchEnd = sceneDepth * _ProjectionParams.z;
}
#else
if(_EnviroDepthTest > 0 )
{
if (sceneDepth >= 0.99f)
{
raymarchEnd = maxRange;
}
else
{
raymarchEnd = sceneDepth * _ProjectionParams.z;
}
}
else
{
raymarchEnd = maxRange;
}
#endif
return raymarchEnd;
}
float4 GetHeightGradient(float cloudType)
{
// x,y = bottom smoothstep, z,w = top smoothstep
const float4 CloudGradient1 = float4(0.0, 0.07, 0.08, 0.15); // Strato
const float4 CloudGradient2 = float4(0.0, 0.20, 0.42, 0.60); // Cumulus
const float4 CloudGradient3 = float4(0.0, 0.08, 0.75, 0.98); // Nimbus
float a = 1.0 - saturate(cloudType * 2.0); // 0→0.5 strato
float b = 1.0 - abs(cloudType - 0.5) * 2.0; // around 0.5 cumulus
float c = saturate(cloudType - 0.5) * 2.0; // 0.5→1 nimbus
return CloudGradient1 * a + CloudGradient2 * b + CloudGradient3 * c;
}
float GradientStep(float a, float4 g)
{
return smoothstep(g.x, g.y, a) - smoothstep(g.z, g.w, a);
}
// ---------- Final profile with varying bottom ----------
float CloudTypeShaping(float3 worldPos, float cloudType, RaymarchParameters p)
{
float _BottomVariation = 1000; // e.g. 500.0 m of random variation
float _NoiseScale = 0.000025; // e.g. 0.001 for slow world-scale noise
// noise-based base variation
float baseOffset = 0;
#if ENVIRO_VARIABLE_BOTTOM
baseOffset = tex2Dlod(_BottomsOffsetNoise, float4(worldPos.xz * _NoiseScale,0,0)).r * _BottomVariation;
#endif
float bottom = p.cloudsParameter.x + baseOffset;
float top = bottom + (p.cloudsParameter.y - p.cloudsParameter.x);
// normalized height
float h = saturate((worldPos.y - bottom) / (top - bottom));
// choose gradient band based on type
float4 gradient = GetHeightGradient(cloudType);
// final vertical profile
return GradientStep(h, gradient);
}
float CloudVerticalShaping(float heightNorm,
float bottomCtrl,
float midCtrl,
float topCtrl,
float ramp)
{
// --- Define segments ---
float2 bottomRange = float2(-0.1, 0.25);
float2 midRange = float2(0.20, 0.45);
float2 topRange = float2(0.40, 0.8); // top segment fades before 1.0
// --- Compute smooth ramps ---
float bottom = smoothstep(bottomRange.x, bottomRange.y, heightNorm) *
(1.0 - smoothstep(bottomRange.x + ramp, bottomRange.y + ramp, heightNorm));
float mid = smoothstep(midRange.x, midRange.y, heightNorm) *
(1.0 - smoothstep(midRange.x + ramp, midRange.y + ramp, heightNorm));
float top = smoothstep(topRange.x, topRange.y, heightNorm) *
(1.0 - smoothstep(topRange.x + ramp, topRange.y + ramp, heightNorm));
// --- Fade top influence out at absolute top ---
//top *= 1.0 - smoothstep(0.95, 1.0, heightNorm);
// --- Normalize weights so controls are balanced ---
float sum = bottom + mid + top + 1e-5;
bottom /= sum;
mid /= sum;
top /= sum;
// --- Apply coverage controls ---
float bias = bottomCtrl * bottom + midCtrl * mid + topCtrl * top;
// --- Map to envelope multiplier ---
// center at 1.0 = no change, limit to avoid full fill
float envelope = 1.0 + bias * 0.5; // adjust scale as needed
//envelope = envelope;
//Bottom Round
float edgeRound = 1.0 - exp(-heightNorm * 8.0);
envelope *= lerp(1.0, edgeRound, 0.9 * bottom);
// --- Subtle round-top modifier ---
float edgeRoundTop = 1.0 - exp(-(1.0 - heightNorm) * 8.0); // only affects highest ~0.81.0
envelope *= lerp(1.0, edgeRoundTop, 1.5 * top);
if(heightNorm > 0.90)
envelope = 0;
return envelope;
}
float CloudTopLayer(float heightNorm, float baseNoise, float topLayerAdd)
{
const float topMin = 0.90;
const float topMax = 0.94;
float verticalFalloff = smoothstep(topMin, topMax, heightNorm) - smoothstep(topMax, 1.0, heightNorm);
float coverage = baseNoise;
return verticalFalloff * coverage * topLayerAdd;
}
// Sample Cloud Density
float CalculateCloudDensity(float3 pos, float3 PlanetCenter, RaymarchParameters parameters, float4 weather, float mip, float lod, bool details)
{
const float baseFreq = 1e-5;
// Get Height fraction
float height = GetSamplingHeight(pos, PlanetCenter, parameters.cloudsParameter);
// wind settings
float cloud_top_offset = 2000.0;
float3 wind_direction = float3(_CloudsWindDirection.x, 0.0, _CloudsWindDirection.y);
// skew in wind direction
pos += height * wind_direction * cloud_top_offset;
float mip1 = mip + lod;
float4 coord = float4(pos * baseFreq * parameters.baseNoiseUV, mip1);
// Animate Wind
coord.xyz += float3(_CloudsWindDirection.z, 0.0f, _CloudsWindDirection.w) * 14;
float4 baseNoise = _Noise.SampleLevel(sampler_Noise, coord.xyz,coord.w) * parameters.baseNoiseMultiplier;
float low_freq_fBm = (baseNoise.g * 0.625) + (baseNoise.b * 0.25) + (baseNoise.a * 0.125);
float base_cloud = RemapEnviro(baseNoise.r, -(1.0 - low_freq_fBm) * (parameters.baseErosionIntensity), 1.0, 0.0, 1.0) ;
float targetShape = CloudVerticalShaping(height,parameters.bottomShape,parameters.midShape,parameters.topShape,parameters.rampShape);
float heightGradient = CloudTypeShaping(pos,saturate(weather.g + 0.1), parameters);
float shapedCloud = base_cloud * targetShape;
shapedCloud *= lerp(1.0, heightGradient, parameters.cloudTypeShaping);
shapedCloud += CloudTopLayer(height, base_cloud, parameters.topLayer);
float cloud_coverage = saturate(1-weather.r);
if(height > 0.90)
cloud_coverage = saturate(1-weather.b);
float cloudDensity = RemapEnviro(shapedCloud, cloud_coverage, 1.0, 0.0, 1.0);
//DETAIL
[branch]
if (details)
{
float mip2 = mip + lod;
coord = float4(pos * baseFreq * parameters.detailNoiseUV, mip2);
//Curl
float distToCam = distance(pos, _WorldSpaceCameraPos);
float curlFade = saturate(1.0 - distToCam / 20000.0f);
float2 curlA = _CurlNoise.SampleLevel(sampler_CurlNoise, coord.xz * 2, 0).rg * 2 - 1;
float2 curlB = _CurlNoise.SampleLevel(sampler_CurlNoise, coord.xy * 3, 0).rg * 2 - 1;
float2 curl = lerp(curlA, curlB, 0.5);
float curlAmp = 0.5 * parameters.attenuation * curlFade;
curl *= curlAmp * saturate(height * 2);
coord.xy += curl;
coord.xz += curl * 0.5;
coord.xyz += float3(_CloudsWindDirection.z * 14, _CloudsAnimation.z, _CloudsWindDirection.w * 14);
float3 detailNoise = _DetailNoise.SampleLevel(sampler_DetailNoise, coord.xyz, coord.w).rgb * parameters.detailNoiseMultiplier;
float high_freq_fBm = (detailNoise.r * 0.625) + (detailNoise.g * 0.25) + (detailNoise.b * 0.125);
float high_freq_noise_modifier = lerp(high_freq_fBm, 1.0f - high_freq_fBm, saturate(height * 8));
cloudDensity = RemapEnviro(cloudDensity, saturate(high_freq_noise_modifier * parameters.detailErosionIntensity), 1.0, 0.0, 1.0);
}
if(height > 0.9)
cloudDensity *= 0.2;
return cloudDensity;
}
static const float shadowSampleDistance[5] = {0.5, 2, 8, 12, 32};
static const float LightingInfluence[5] = {5, 4, 3, 2, 1};
float GetDensityAlongRay(float3 pos,float3 PlanetCenter,RaymarchParameters parameters,float3 LightDirection,float4 weather,float lod)
{
float mipBiasScale = 0.1;
float opticalDepth = 0.0;
float mipOffset = 0.0;
float distanceTraveled = 0.0;
[loop]
for (int i = 0; i < 5; i++)
{
// Base step size from shadowSampleDistance
float baseStep = shadowSampleDistance[i] * (512.0 * _CloudsLightingExtended.z);
distanceTraveled += baseStep;
// Sample cloud density
float3 samplePos = pos + LightDirection * distanceTraveled;
float density = 0;
if(i < 4)
density = CalculateCloudDensity(samplePos, PlanetCenter, parameters, weather, mipOffset, lod, true) * 0.75;
else
density = CalculateCloudDensity(samplePos, PlanetCenter, parameters, weather, mipOffset, lod, false) * 0.75;
opticalDepth += LightingInfluence[i] * density * baseStep;
// Update mip offset proportionally
mipOffset += saturate(baseStep * mipBiasScale);
}
return opticalDepth;
}
float3 _LightningCenter;
float _LightningRadius;
float _LightningStart;
float _LightningDuration;
float _GlobalTime;
float LightningIntensity(float t)
{
if (t < 0 || t > _LightningDuration) return 0;
// ---- Parameters ----
float flickerStrength = 0.25; // 0..1 amplitude of flicker
float flickerCycles = 3; // number of flickers across duration
float endBoost = 2; // 1 = none, 2 = double brightness at end
// ---- Duration-based scaling ----
float riseRate = 1.0 / max(0.15 * _LightningDuration, 0.001);
float decayRate = 1.0 / max(_LightningDuration, 0.001);
float rise = saturate(t * riseRate);
float decay = exp(-t * decayRate * _LightningDuration);
float envelope = rise * decay;
// ---- Flicker ----
float flickerFreq = flickerCycles / max(_LightningDuration, 0.001);
float flicker = 1.0 + flickerStrength * sin(t * flickerFreq * 6.2831853);
// ---- Late-time boost ----
// Progress through flash (0 → 1)
float progress = saturate(t / _LightningDuration);
// Stronger near the end (ease-in curve)
float lateBoost = 1.0 + (endBoost - 1.0) * pow(progress, 3.0);
return envelope * flicker * lateBoost;
}
float SampleEnergy(
float3 pos, float cosTheta, float3 center,
RaymarchParameters p, float3 LightDirection,
float height, float ds_lod, float step_size,
float4 weather, float lod, float gradApprox)
{
//--------------------------------
// 1. Optical depth along light
//--------------------------------
float tau = GetDensityAlongRay(pos, center, p, LightDirection, weather, lod);
float sigma_t = max(p.lightAbsorb, 0.0005);
float opticalD = sigma_t * tau;
//--------------------------------
// 2. Direct scattering (HG + edge highlight coupled)
//--------------------------------
float T = exp(-opticalD);
float g = 0.85 - p.silverLiningSpread;
float hgForward = HenryGreensteinNorm(cosTheta, g);
float hgIso = 0.25 * INV_PI * p.edgeHighlightStrength;
float phase = hgIso + hgForward;
float direct = T * phase * p.scatteringCoef * 20.0 * max(_SolarTime,0.25) * p.silverLiningIntensity;
//--------------------------------
// 3. Multi-scattering (indirect)
//--------------------------------
float msEnergy = p.multiScatterStrength * (1.0 - T) * exp(-opticalD * p.multiScatterFalloff);
float phaseMS = 0.25 * INV_PI;
float indirect = msEnergy * phaseMS * p.scatteringCoef * 20.0;
//--------------------------------
// 3a Distance Clouds Tweaks
//--------------------------------
float distToCam = length(pos - _WorldSpaceCameraPos);
float distFactor = saturate(distToCam / 7000);
// Push balance toward indirect at distance
float indirectBoost = lerp(1.0, 1.5, distFactor); // 1.0 near, 1.5 far
float directFade = lerp(1.0, 0.7, distFactor); // keep direct a bit weaker far
direct *= directFade;
indirect *= indirectBoost;
//--------------------------------
// 4. Ambient floor
//--------------------------------
float ambientFloor = p.ambientFloor * (1.0 - exp(-opticalD * 0.1));
//--------------------------------
// 5. Lightning
//--------------------------------
float lightning = 0.0;
#if ENVIRO_LIGHTNING
float dist = length(pos - _LightningCenter);
float softness = 0.5;
float falloff = exp(-pow(dist / _LightningRadius, 2.0) * softness);
float flash = LightningIntensity(_Time.y - _LightningStart);
float densityAtten = exp(-tau * 0.004);
lightning = flash * falloff * densityAtten * 100.0 * (10 * saturate(1 - _SolarTime));
#endif
//--------------------------------
// 6. Combine total energy
//--------------------------------
float energy = direct + indirect + ambientFloor + lightning;
return max(energy * p.exposure, 0.0);
}
float2 squareUV(float2 uv)
{
float width = _Resolution.x;
float height = _Resolution.y;
float scale = 400;
float x = uv.x * width;
float y = uv.y * height;
return float2 (x/scale, y/scale);
}
bool ray_trace_sphere(float3 center, float3 rd, float3 offset, float radius, out float t1, out float t2) {
float3 p = center - offset;
float b = dot(p, rd);
float c = dot(p, p) - (radius * radius);
float f = b * b - c;
if (f >= 0.0) {
float dem = sqrt(f);
t1 = -b - dem;
t2 = -b + dem;
return true;
}
return false;
}
bool resolve_ray_start_end(float3 ws_origin, float3 ws_ray, float3 center, RaymarchParameters parameter, out float start, out float end)
{
start = 0;
end = 0;
//case includes on ground, inside atm, above atm.
float ot1, ot2, it1, it2;
bool outIntersected = ray_trace_sphere(ws_origin, ws_ray, center, parameter.cloudsParameter.w + parameter.cloudsParameter.y, ot1, ot2);
if (!outIntersected || ot2 < 0.0f)
return false; //you see nothing.
bool inIntersected = ray_trace_sphere(ws_origin, ws_ray, center, parameter.cloudsParameter.w + parameter.cloudsParameter.x, it1, it2);
if (inIntersected)
{
if (it1 * it2 < 0)
{
//we're on ground.
start = max(it2, 0);
end = ot2;
}
else
{
start = 0.0f;
//we're inside atm, or above atm.
if (ot1 * ot2 < 0.0)
{
//Inside atm.
if (it2 > 0.0)
{
//Look down.
end = it1;
}
else
{
//Look up.
end = ot2;
}
start = 0.0f;
}
else
{ //Outside atm
if (ot1 < 0.0)
{
return false;
}
else
{
start = ot1;
end = it1;
}
}
}
}
else
{
end = ot2;
start = max(ot1, 0);
}
return true;
}
int inside = 0;
float2 ResolveRay(float3 pos, float3 ray, float3 center, float raymarchEnd, RaymarchParameters parameter)
{
float sampleStart = 0;
float sampleEnd = 0;
if (!resolve_ray_start_end(pos, ray,center, parameter, sampleStart, sampleEnd))
{
return float2(0,0);
}
float3 sampleStartPos = pos + (ray * sampleStart);
if (sampleEnd <= sampleStart)
{
return float2(0,0);
}
float ch = length(pos - center) - parameter.cloudsParameter.w;
//float height = RemapEnviro(pos.y, parameter.cloudsParameter.x, parameter.cloudsParameter.y * 0.75, 0, 1);
//float end = lerp(_CloudsCoverageSettings.y * 0.85,_CloudsCoverageSettings.y * 1.25,height);
raymarchEnd = min(raymarchEnd, _CloudsCoverageSettings.y);
if (ch < parameter.cloudsParameter.x)
{
sampleEnd = min(raymarchEnd, sampleEnd);
inside = 0;
if(ray.y < 0)
return float2(0,0);
}
else if (ch > parameter.cloudsParameter.y)
{
sampleEnd = min(raymarchEnd, sampleEnd);
inside = 0;
}
else
{
sampleEnd = min(raymarchEnd, sampleEnd);
inside = 0;
}
return float2(max(0.0f,sampleStart), min(raymarchEnd, sampleEnd));
}
float CalculateLodMips(float distanceToCamera)
{
return lerp(0.0, lerp(5.0,0.0,_LODDistance), saturate((distanceToCamera - 3000.0) / (100000.0 - 3000.0)));
}
float3 Raymarch (float3 cameraPos, float3 ray, float2 hitDistance, float3 center, RaymarchParameters parameters, float offset)
{
float cloud_test = 0.0;
int zero_density_sample_count = 0;
float sampled_density_previous = -1.0;
float alpha = 1.0;
float intensity = 0.0;
float depth = 0.0;
float depthWeightSum = 0.000001;
float trans = 1.0f;
int steps = (int)lerp(parameters.minSteps, parameters.maxSteps, ray.y);
//int steps = parameters.maxSteps;
float rayStepLength = (hitDistance.y - hitDistance.x) / steps;
float3 rayStep = ray * rayStepLength;
float3 pos = (cameraPos + (hitDistance.x) * ray);
pos += (offset * rayStepLength) * ray;
//pos += rayStep;
pos += rayStep;
float3 sampleEndPos = cameraPos + ray * hitDistance.y;
float eyeToEnd = distance(cameraPos, sampleEndPos);
float cosTheta = dot(ray, normalize(_LightDir));
[loop]
for (int i = 0; i < steps; i++)
{
//Calculate projection height
float height = GetSamplingHeight(pos, center, parameters.cloudsParameter);
//Get out of expensive raymarching
if (alpha <= 0.01 || height > 1.0 || height < 0.0 || _CloudsCoverageSettings.x <= -0.9)
break;
// Get Weather Data
float4 weather = GetWeather(pos);
float distanceToCamera = length(pos - cameraPos);
float lod = CalculateLodMips(distanceToCamera);
if (cloud_test > 0.0)
{
float sampled_density = CalculateCloudDensity(pos, center, parameters, weather, 0, lod, true);
if (sampled_density == 0.0 && sampled_density_previous == 0.0)
{
zero_density_sample_count++;
}
if (zero_density_sample_count < 8 && sampled_density != 0.0)
{
float extinction = pow(max(parameters.density * sampled_density,0.001),parameters.densitySmoothness);
float clampedExtinction = max(extinction, 1e-7);
float transmittance = exp(-extinction * rayStepLength);
float gradApprox = abs(sampled_density - sampled_density_previous);
// edge-sensitive ds_lod
float ds_lod_local = sampled_density * (1.0 + lod * 0.8);
float luminance = SampleEnergy(pos, cosTheta, center, parameters, _LightDir, height, sampled_density, rayStepLength,weather,lod,gradApprox);
float integScatt = (luminance - luminance * transmittance);
float depthWeight = trans;
depth += depthWeight * distanceToCamera;
depthWeightSum += depthWeight;
intensity += trans * integScatt;
trans *= transmittance;
alpha *= max(transmittance, 0.0);
if (alpha <= 0.01)
alpha = 0.0;
}
// if not, then set cloud_test to zero so that we go back to the cheap sample case
else if(zero_density_sample_count >= 8)
{
cloud_test = 0.0;
zero_density_sample_count = 0;
}
sampled_density_previous = sampled_density;
pos += rayStep;
}
else
{
// sample density the cheap way, only using the low frequency noise
cloud_test = CalculateCloudDensity(pos, center, parameters, weather, 0, lod, (bool)inside);
if (cloud_test == 0.0)
{
pos += rayStep * 2;
}
else //take a step back and capture area we skipped.
{
pos -= rayStep;
}
}
}
float distance = depth / depthWeightSum;
if (distance <= 0.0)
{
distance = length(sampleEndPos - cameraPos);
}
alpha = saturate(1.0f - alpha);
return float3(intensity,distance,alpha);
}
float3 CalculateWorldPosition (float2 uv, float depth)
{
float4x4 proj, eyeToWorld;
if (unity_StereoEyeIndex == 0)
{
proj = _LeftViewFromScreen;
eyeToWorld = _LeftWorldFromView;
}
else
{
proj = _RightViewFromScreen;
eyeToWorld = _RightWorldFromView;
}
//bit of matrix math to take the screen space coord (u,v,depth) and transform to world space
float2 uvClip = uv * 2.0 - 1.0;
float clipDepth = depth; // Fix for OpenGl Core thanks to Lars Bertram
clipDepth = (UNITY_NEAR_CLIP_VALUE < 0) ? clipDepth * 2 - 1 : clipDepth;
float4 clipPos = float4(uvClip, clipDepth, 1.0);
float4 viewPos = mul(proj, clipPos); // inverse projection by clip position
viewPos /= viewPos.w; // perspective division
return float3(mul(eyeToWorld, viewPos).xyz);
}
float RaymarchShadows (float3 cameraPos, float3 worldPos,float3 ray,float3 center, RaymarchParameters parameters, float offset,float depth)
{
if(depth == 0.0f)
return 0.0;
int steps = 16;
float worldDotLight = saturate(dot(float3(0, 1, 0), _LightDir));
float bottomDist = max(0, parameters.cloudsParameter.x ) / worldDotLight;
float topDist = max(0, parameters.cloudsParameter.y ) / worldDotLight;
float rayStepLength = (topDist - bottomDist) / steps;
float3 rayStep = _LightDir * rayStepLength;
float3 pos = worldPos + bottomDist * _LightDir;
float4 weather = GetWeather(pos);
float intensity = 0.05;
float shadowIntensity = 0.0;
float _Softness = 2.0f;
[unroll]
for (int i = 0; i < steps; i++)
{
float3 samplePos = rayStepLength * i * _LightDir + pos;
float sampleResult = CalculateCloudDensity(samplePos, center, parameters, weather, 0, 0, true) * intensity;
float result = sampleResult * (rayStepLength / (i + 1));
shadowIntensity += result;
// if (shadowIntensity > 0.99)
// break;
}
return (shadowIntensity);
}