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354 行
15 KiB
354 行
15 KiB
#ifndef FILE_ATMOSPHERICSCATTERING
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#define FILE_ATMOSPHERICSCATTERING
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#define ATMOSPHERICS_DBG_NONE 0
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#define ATMOSPHERICS_DBG_SCATTERING 1
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#define ATMOSPHERICS_DBG_OCCLUSION 2
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#define ATMOSPHERICS_DBG_OCCLUDEDSCATTERING 3
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#define ATMOSPHERICS_DBG_RAYLEIGH 4
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#define ATMOSPHERICS_DBG_MIE 5
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#define ATMOSPHERICS_DBG_HEIGHT 6
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uniform int _AtmosphericsDebugMode;
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uniform float3 _SunDirection;
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uniform float _ShadowBias;
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uniform float _ShadowBiasIndirect;
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uniform float _ShadowBiasClouds;
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uniform float _OcclusionDepthThreshold;
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uniform float4 _OcclusionTexture_TexelSize;
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uniform float4 _DepthTextureScaledTexelSize;
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uniform float _WorldScaleExponent;
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uniform float _WorldNormalDistanceRcp;
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uniform float _WorldNearScatterPush;
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uniform float _WorldRayleighDensity;
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uniform float _WorldMieDensity;
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uniform float3 _RayleighColorM20;
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uniform float3 _RayleighColorM10;
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uniform float3 _RayleighColorO00;
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uniform float3 _RayleighColorP10;
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uniform float3 _RayleighColorP20;
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uniform float3 _RayleighColorP45;
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uniform float3 _MieColorM20;
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uniform float3 _MieColorO00;
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uniform float3 _MieColorP20;
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uniform float3 _MieColorP45;
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uniform float _HeightNormalDistanceRcp;
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uniform float _HeightNearScatterPush;
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uniform float _HeightRayleighDensity;
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uniform float _HeightMieDensity;
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uniform float _HeightSeaLevel;
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uniform float3 _HeightPlaneShift;
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uniform float _HeightDistanceRcp;
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uniform float _RayleighCoeffScale;
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uniform float3 _RayleighSunTintIntensity;
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uniform float2 _RayleighInScatterPct;
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uniform float _MieCoeffScale;
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uniform float3 _MieSunTintIntensity;
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uniform float _MiePhaseAnisotropy;
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uniform float _HeightExtinctionFactor;
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uniform float _RayleighExtinctionFactor;
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uniform float _MieExtinctionFactor;
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uniform float4 _HeightRayleighColor;
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SAMPLER2D(sampler_CameraDepthTexture)
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#define SRL_BilinearSampler sampler_CameraDepthTexture // Used for all textures
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TEXTURE2D(_CameraDepthTexture);
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TEXTURE2D(_OcclusionTexture);
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float HenyeyGreensteinPhase(float g, float cosTheta) {
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float gSqr = g * g;
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float a1 = (1.f - gSqr);
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float a2 = (2.f + gSqr);
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float b1 = 1.f + cosTheta * cosTheta;
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float b2 = pow(abs(1.f + gSqr - 2.f * g * cosTheta), 1.5f);
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return (a1 / a2) * (b1 / b2);
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}
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float RayleighPhase(float cosTheta) {
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const float f = 3.f / (16.f * PI);
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return f + f * cosTheta * cosTheta;
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}
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float MiePhase(float cosTheta, float anisotropy) {
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const float f = 3.f / (8.f * PI);
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return f * HenyeyGreensteinPhase(anisotropy, cosTheta);
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}
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float HeightDensity(float h, float H) {
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return exp(-h/H);
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}
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float3 WorldScale(float3 p) {
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p.xz = sign(p.xz) * pow(abs(p.xz), _WorldScaleExponent);
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return p;
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}
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void VolundTransferScatter(float3 worldPos, out float4 coords1, out float4 coords2, out float4 coords3) {
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const float3 scaledWorldPos = WorldScale(worldPos);
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const float3 worldCamPos = WorldScale(_WorldSpaceCameraPos.xyz);
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const float c_MieScaleHeight = 1200.f;
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const float worldRayleighDensity = 1.f;
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const float worldMieDensity = HeightDensity(scaledWorldPos.y, c_MieScaleHeight);
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const float3 worldVec = scaledWorldPos.xyz - worldCamPos.xyz;
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const float worldVecLen = length(worldVec);
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const float3 worldDir = worldVec / worldVecLen;
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const float3 worldDirUnscaled = normalize(worldPos - _WorldSpaceCameraPos.xyz);
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const float viewSunCos = dot(worldDirUnscaled, _SunDirection);
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const float rayleighPh = min(1.f, RayleighPhase(viewSunCos) * 12.f);
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const float miePh = MiePhase(viewSunCos, _MiePhaseAnisotropy);
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const float angle20 = 0.324f / 1.5f;
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const float angle10 = 0.174f / 1.5f;
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const float angleY = worldDir.y * saturate(worldVecLen / 250.0);
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float3 rayleighColor;
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if(angleY >= angle10) rayleighColor = lerp(_RayleighColorP10, _RayleighColorP20, saturate((angleY - angle10) / (angle20 - angle10)));
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else if(angleY >= 0.f) rayleighColor = lerp(_RayleighColorO00, _RayleighColorP10, angleY / angle10);
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else if(angleY >= -angle10) rayleighColor = lerp(_RayleighColorM10, _RayleighColorO00, (angleY + angle10) / angle10);
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else rayleighColor = lerp(_RayleighColorM20, _RayleighColorM10, saturate((angleY + angle20) / (angle20 - angle10)));
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float3 mieColor;
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if(angleY >= 0.f) mieColor = lerp(_MieColorO00, _MieColorP20, saturate(angleY / angle20));
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else mieColor = lerp(_MieColorM20, _MieColorO00, saturate((angleY + angle20) / angle20));
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const float pushedDistance = max(0.f, worldVecLen + _WorldNearScatterPush);
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const float pushedDensity = /*HeightDensity **/ pushedDistance /** exp(-scaledWorldPos.y / 8000.f)*/;
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const float rayleighScatter = (1.f - exp(_WorldRayleighDensity * pushedDensity)) * rayleighPh;
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#ifdef IS_RENDERING_SKY
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const float mieScatter = (1.f - exp(_WorldMieDensity * pushedDensity));
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#else
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const float mieScatter = (1.f - exp(_WorldMieDensity * pushedDensity)) * miePh;
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#endif
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const float heightShift = dot(worldVec, _HeightPlaneShift);
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const float heightScaledOffset = (scaledWorldPos.y - heightShift - _HeightSeaLevel) * _HeightDistanceRcp;
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const float HeightDensity = exp(-heightScaledOffset);
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const float pushedHeightDistance = max(0.f, worldVecLen + _HeightNearScatterPush);
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const float heightScatter = (1.f - exp(_HeightRayleighDensity * pushedHeightDistance)) * HeightDensity;
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#ifdef IS_RENDERING_SKY
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const float heightMieScatter = (1.f - exp(_HeightMieDensity * pushedHeightDistance)) * HeightDensity;
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#else
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const float heightMieScatter = (1.f - exp(_HeightMieDensity * pushedHeightDistance)) * HeightDensity * miePh;
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#endif
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rayleighColor = lerp(Luminance(rayleighColor).rrr, rayleighColor, saturate(pushedDistance * _WorldNormalDistanceRcp));
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float3 heightRayleighColor = lerp(Luminance(_HeightRayleighColor.xyz).rrr, _HeightRayleighColor.xyz, saturate(pushedHeightDistance * _HeightNormalDistanceRcp));
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coords1.rgb = rayleighScatter * rayleighColor;
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coords1.a = rayleighScatter;
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coords3.rgb = saturate(heightScatter) * heightRayleighColor;
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coords3.a = heightScatter;
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coords2.rgb = mieScatter * mieColor + saturate(heightMieScatter) * mieColor;
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coords2.a = mieScatter;
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}
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void VolundTransferScatter(float3 scaledWorldPos, out float4 coords1) {
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float4 c1, c2, c3;
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VolundTransferScatter(scaledWorldPos, c1, c2, c3);
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#ifdef IS_RENDERING_SKY
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coords1.rgb = c3.rgb;
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coords1.a = max(0.f, 1.f - c3.a * _HeightExtinctionFactor);
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#else
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coords1.rgb = c1.rgb;
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coords1.rgb += c3.rgb;
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coords1.a = max(0.f, 1.f - c1.a * _RayleighExtinctionFactor - c3.a * _HeightExtinctionFactor);
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#endif
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coords1.rgb += c2.rgb;
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coords1.a *= max(0.f, 1.f - c2.a * _MieExtinctionFactor);
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#ifdef ATMOSPHERICS_DEBUG
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if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_RAYLEIGH)
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coords1.rgb = c1.rgb;
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else if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_MIE)
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coords1.rgb = c2.rgb;
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else if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_HEIGHT)
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coords1.rgb = c3.rgb;
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#endif
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}
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float2 UVFromPos(float2 pos) {
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return pos / _ScreenParams.xy;
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}
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float3 VolundApplyScatter(float4 coords1, float2 pos, float3 color) {
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#ifdef ATMOSPHERICS_DEBUG
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if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_OCCLUSION)
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return 1;
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else if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_SCATTERING || _AtmosphericsDebugMode == ATMOSPHERICS_DBG_OCCLUDEDSCATTERING)
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return coords1.rgb;
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else if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_RAYLEIGH || _AtmosphericsDebugMode == ATMOSPHERICS_DBG_MIE || _AtmosphericsDebugMode == ATMOSPHERICS_DBG_HEIGHT)
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return coords1.rgb;
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#endif
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return color * coords1.a + coords1.rgb;
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}
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float3 VolundApplyScatterAdd(float coords1, float3 color) {
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return color * coords1;
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}
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void VolundTransferScatterOcclusion(float3 scaledWorldPos, out float4 coords1, out float3 coords2) {
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float4 c1, c2, c3;
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VolundTransferScatter(scaledWorldPos, c1, c2, c3);
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coords1.rgb = c1.rgb * _RayleighInScatterPct.x;
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coords1.a = max(0.f, 1.f - c1.a * _RayleighExtinctionFactor - c3.a * _HeightExtinctionFactor);
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coords1.rgb += c2.rgb;
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coords1.a *= max(0.f, 1.f - c2.a * _MieExtinctionFactor);
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coords2.rgb = c3.rgb + c1.rgb * _RayleighInScatterPct.y;
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#ifdef ATMOSPHERICS_DEBUG
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if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_RAYLEIGH)
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coords1.rgb = c1.rgb;
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else if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_MIE)
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coords1.rgb = c2.rgb;
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else if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_HEIGHT)
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coords1.rgb = c3.rgb;
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#endif
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}
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float VolundSampleScatterOcclusion(float2 pos) {
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#if defined(ATMOSPHERICS_OCCLUSION)
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float2 uv = UVFromPos(pos);
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#if defined(ATMOSPHERICS_OCCLUSION_EDGE_FIXUP)
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float4 baseUV = float4(uv.x, uv.y, 0.f, 0.f);
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float cDepth = SAMPLE_TEXTURE2D_LOD(_CameraDepthTexture, SRL_BilinearSampler, baseUV, 0.f).r;
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cDepth = LinearEyeDepth(cDepth);
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float4 xDepth;
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baseUV.xy = uv + _DepthTextureScaledTexelSize.zy; xDepth.x = SAMPLE_TEXTURE2D_LOD(_CameraDepthTexture, SRL_BilinearSampler, baseUV);
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baseUV.xy = uv + _DepthTextureScaledTexelSize.xy; xDepth.y = SAMPLE_TEXTURE2D_LOD(_CameraDepthTexture, SRL_BilinearSampler, baseUV);
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baseUV.xy = uv + _DepthTextureScaledTexelSize.xw; xDepth.z = SAMPLE_TEXTURE2D_LOD(_CameraDepthTexture, SRL_BilinearSampler, baseUV);
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baseUV.xy = uv + _DepthTextureScaledTexelSize.zw; xDepth.w = SAMPLE_TEXTURE2D_LOD(_CameraDepthTexture, SRL_BilinearSampler, baseUV);
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xDepth.x = LinearEyeDepth4(xDepth.x);
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xDepth.y = LinearEyeDepth4(xDepth.y);
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xDepth.z = LinearEyeDepth4(xDepth.z);
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xDepth.w = LinearEyeDepth4(xDepth.w);
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float4 diffDepth = xDepth - cDepth.rrrr;
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float4 maskDepth = abs(diffDepth) < _OcclusionDepthThreshold;
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float maskWeight = dot(maskDepth, maskDepth);
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UNITY_BRANCH
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if(maskWeight == 4.f || maskWeight == 0.f) {
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return SAMPLE_TEXTURE2D_LOD(_OcclusionTexture, SRL_BilinearSampler, uv, 0.f).r;
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} else {
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float4 occ = GATHER_TEXTURE2D(_OcclusionTexture, SRL_BilinearSampler, uv);
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float4 fWeights;
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fWeights.xy = frac(uv * _OcclusionTexture_TexelSize.zw - 0.5f);
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fWeights.zw = float2(1.f, 1.f) - fWeights.xy;
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float4 mfWeights = float4(fWeights.z * fWeights.y, fWeights.x * fWeights.y, fWeights.x * fWeights.w, fWeights.z * fWeights.w);
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return dot(occ, mfWeights * maskDepth) / dot(mfWeights, maskDepth);
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}
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#endif //defined(ATMOSPHERICS_OCCLUSION_EDGE_FIXUP)
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#else //defined(ATMOSPHERICS_OCCLUSION)
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return 1.f;
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#endif //defined(ATMOSPHERICS_OCCLUSION)
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}
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float3 VolundApplyScatterOcclusion(float4 coords1, float3 coords2, float2 pos, float3 color) {
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float occlusion = VolundSampleScatterOcclusion(pos);
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#ifdef ATMOSPHERICS_DEBUG
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if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_SCATTERING)
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return coords1.rgb + coords2.rgb;
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else if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_OCCLUSION)
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return occlusion;
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else if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_OCCLUDEDSCATTERING)
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return coords1.rgb * min(1.f, occlusion + _ShadowBias) + coords2.rgb * min(1.f, occlusion + _ShadowBiasIndirect);
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else if(_AtmosphericsDebugMode == ATMOSPHERICS_DBG_RAYLEIGH || _AtmosphericsDebugMode == ATMOSPHERICS_DBG_MIE || _AtmosphericsDebugMode == ATMOSPHERICS_DBG_HEIGHT)
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return coords1.rgb;
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#endif
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return
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color * coords1.a
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+ coords1.rgb * min(1.f, occlusion + _ShadowBias) + coords2.rgb * min(1.f, occlusion + _ShadowBiasIndirect);
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;
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}
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float VolundCloudOcclusion(float2 pos) {
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#if defined(ATMOSPHERICS_OCCLUSION)
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return min(1.f, VolundSampleScatterOcclusion(pos) + _ShadowBiasClouds);
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#else
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return 1.f;
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#endif
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}
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float4 VolundApplyCloudScatter(float4 coords1, float4 color) {
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#if defined(DBG_ATMOSPHERICS_SCATTERING) || defined(DBG_ATMOSPHERICS_OCCLUDEDSCATTERING)
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return float4(coords1.rgb, color.a);
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#elif defined(DBG_ATMOSPHERICS_OCCLUSION)
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return 1;
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#endif
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color.rgb = color.rgb * coords1.a + coords1.rgb;
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return color;
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}
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float4 VolundApplyCloudScatterOcclusion(float4 coords1, float3 coords2, float2 pos, float4 color) {
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float occlusion = VolundSampleScatterOcclusion(pos);
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#ifdef ATMOSPHERICS_OCCLUSION_DEBUG2
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color.rgb = coords1.rgb * min(1.f, occlusion + _ShadowBias) + coords2.rgb * min(1.f, occlusion + _ShadowBiasIndirect);
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return color;
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#endif
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#ifdef ATMOSPHERICS_OCCLUSION_DEBUG
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return occlusion;
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#endif
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color.rgb = color.rgb * coords1.a + coords1.rgb * min(1.f, occlusion + _ShadowBias) + coords2.rgb * min(1.f, occlusion + _ShadowBiasIndirect);
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float cloudOcclusion = min(1.f, occlusion + _ShadowBiasClouds);
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color.a *= cloudOcclusion;
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return color;
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}
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// Original vert/frag macros
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#if defined(ATMOSPHERICS_OCCLUSION)
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#define VOLUND_SCATTER_COORDS(idx1, idx2) float4 scatterCoords1 : TEXCOORD##idx1; float3 scatterCoords2 : TEXCOORD##idx2;
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#define VOLUND_TRANSFER_SCATTER(pos, o) o.scatterCoords1 = pos.xyzz; o.scatterCoords2 = pos.xyz;
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#define VOLUND_APPLY_SCATTER(i, color) VolundTransferScatterOcclusion(i.scatterCoords1.xyz, i.scatterCoords1, i.scatterCoords2); color = VolundApplyScatterOcclusion(i.scatterCoords1, i.scatterCoords2, i.pos.xy, color)
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#define VOLUND_CLOUD_SCATTER(i, color) VolundTransferScatterOcclusion(i.scatterCoords1.xyz, i.scatterCoords1, i.scatterCoords2); color = VolundApplyCloudScatterOcclusion(i.scatterCoords1, i.scatterCoords2, i.pos.xy, color)
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#else
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#define VOLUND_SCATTER_COORDS(idx1, idx2) float4 scatterCoords1 : TEXCOORD##idx1;
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#define VOLUND_TRANSFER_SCATTER(pos, o) o.scatterCoords1 = pos.xyzz;
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#define VOLUND_APPLY_SCATTER(i, color) VolundTransferScatter(i.scatterCoords1.xyz, i.scatterCoords1); color = VolundApplyScatter(i.scatterCoords1, i.pos.xy, color);
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#define VOLUND_CLOUD_SCATTER(i, color) VolundTransferScatter(i.scatterCoords1.xyz, i.scatterCoords1); color = VolundApplyCloudScatter(i.scatterCoords1, color);
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#endif
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#if !defined(SURFACE_SCATTER_COORDS)
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/* surface shader analysis currently forces us to include stuff even when unused */
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/* we also have to convince the analyzer to not optimize out stuff we need */
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#define SURFACE_SCATTER_COORDS float3 scaledWorldPos; float4 scatterCoords1; float3 scatterCoords2;
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#define SURFACE_SCATTER_TRANSFER(pos, o) o.scatterCoords1.r = o.scatterCoords2.r = pos.x;
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#define SURFACE_SCATTER_APPLY(i, color) color += (i.scaledWorldPos + i.scatterCoords1.xyz + i.scatterCoords2.xyz) * 0.000001f
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#endif
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#endif //FILE_ATMOSPHERICSCATTERING
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