261 lines
9.6 KiB
Plaintext
261 lines
9.6 KiB
Plaintext
Shader "Unlit/volumeLight"
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{
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Properties {
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_MainTex ("Base (RGB)", 2D) = "white" {}
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}
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SubShader
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{
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Tags { "RenderType"="Opaque" }
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LOD 100
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HLSLINCLUDE
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#pragma multi_compile _ _MAIN_LIGHT_SHADOWS //接受阴影
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#pragma multi_compile _ _MAIN_LIGHT_SHADOWS_CASCADE //产生阴影
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#pragma multi_compile _ _ADDITIONAL_LIGHTS_VERTEX _ADDITIONAL_LIGHTS
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#pragma multi_compile _ _SHADOWS_SOFT //软阴影
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#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
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#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/DeclareDepthTexture.hlsl"
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//#include "Packages/com.unity.render-pipelines.core/Runtime/Utilities/Blit.hlsl"
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#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Lighting.hlsl"
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TEXTURE2D( _MainTex);
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SAMPLER(sampler_MainTex);
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TEXTURE2D( _LightMar); SAMPLER(sampler_LightMar);
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float4 _MainTex_TexelSize;
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float4 _MainTex_ST;
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//步进次数
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int _StepCount;
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//最大步进距离
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float _MaxStepDest;
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static half dither[16] = {
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1.0 / 17.0, 9.0 / 17.0, 3.0 / 17.0, 11.0 / 17.0,
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13.0 / 17.0, 5.0 / 17.0, 15.0 / 17.0, 7.0 / 17.0,
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4.0 / 17.0, 12.0 / 17.0, 2.0 / 17.0, 10.0 / 17.0,
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16.0 / 17.0, 8.0 / 17.0, 14.0 / 17.0, 6.0 / 17.0
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};
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struct Attributes
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{
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float4 positionOS : POSITION;
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float2 uv : TEXCOORD0;
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};
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struct Varyings
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{
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float4 positionCS : SV_POSITION;
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float2 uv : TEXCOORD0;
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};
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float Remap(float x,float inMin,float inMax,float toMin,float toMax)
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{
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return (x-inMin)/(inMax-inMin)*(toMax-toMin)+toMin;
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}
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Varyings vert(Attributes v)
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{
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Varyings o = (Varyings)0;
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o.positionCS = TransformObjectToHClip(v.positionOS.xyz);
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o.uv =v.uv; //TRANSFORM_TEX(v.uv, _MainTex);
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return o;
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}
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float _Strength;
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half4 fragBlend(Varyings i) : SV_Target
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{
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float4 color= SAMPLE_TEXTURE2D(_MainTex,sampler_MainTex, i.uv);
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float4 light= SAMPLE_TEXTURE2D(_LightMar,sampler_LightMar, i.uv);
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color=color*light*2*_Strength+color+light*0.1*_Strength;
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return color;
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}
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float space_sigma;
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float range_sigma ;
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//高斯模糊->双边过滤
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half4 fragBlur(Varyings input) : SV_Target
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{
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float weight_sum = 0;
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float3 color_sum = 0;
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float3 color_origin = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, input.uv);
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float3 color = 0;
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//float space_sigma=2;
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//float range_sigma =5;
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for(int i = -3; i < 3; i++){
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for(int j = -3; j < 3; j++){
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//空域高斯-uv加权
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float2 varible = input.uv + float2(i * _MainTex_TexelSize.x, j * _MainTex_TexelSize.y)*3;
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float space_factor = i * i + j * j;
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space_factor = (-space_factor) / (2 * space_sigma* space_sigma);
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float space_weight = 1/(space_sigma * space_sigma * 2 * PI) * exp(space_factor);
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//值域高斯-颜色加权
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float3 color_neighbor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, varible);
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float3 color_distance = (color_neighbor - color_origin);
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float value_factor = color_distance.r * color_distance.r ;
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value_factor = (-value_factor) / (2 * range_sigma * range_sigma);
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float value_weight = (1 / (2 * PI * range_sigma)) * exp(value_factor);
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weight_sum += space_weight * value_weight;
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color_sum += color_neighbor * space_weight * value_weight;
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}
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}
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color=lerp(color,color_sum / weight_sum,step(0,weight_sum));
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return float4(color,1);
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}
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half4 fragBlurFast(Varyings i) : SV_Target
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{
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float2 size=_MainTex_TexelSize.xy*1;
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float4 result=(SAMPLE_TEXTURE2D(_MainTex,sampler_MainTex, i.uv+int2(1,1)*size)+
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SAMPLE_TEXTURE2D(_MainTex,sampler_MainTex, i.uv+int2(-1,-1)*size)+
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SAMPLE_TEXTURE2D(_MainTex,sampler_MainTex, i.uv+int2(-1,1)*size)+
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SAMPLE_TEXTURE2D(_MainTex,sampler_MainTex, i.uv+int2(1,-1)*size));
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return result*0.25;
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}
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half4 fragBlurFast2(Varyings i) : SV_Target
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{
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float2 size=_MainTex_TexelSize.xy*1;
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float4 result=(SAMPLE_TEXTURE2D(_MainTex,sampler_MainTex, i.uv+int2(0,1)*size)+
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SAMPLE_TEXTURE2D(_MainTex,sampler_MainTex, i.uv+int2(0,-1)*size)+
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SAMPLE_TEXTURE2D(_MainTex,sampler_MainTex, i.uv+int2(-1,0)*size)+
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SAMPLE_TEXTURE2D(_MainTex,sampler_MainTex, i.uv+int2(1,0)*size));
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return result*0.25;
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}
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float Getshadow(float3 posWorld)
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{
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float4 shadowCoord = TransformWorldToShadowCoord(posWorld);
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float shadow = MainLightRealtimeShadow(shadowCoord);
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return shadow;
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}
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//AABB包围盒,一个射线可以得到，打到以某一点为中心的xyz平面上的新射线点
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float2 rayBoxDst(float3 boundsMin,float3 boundsMax,float3 rayOrigin ,float3 rayDir)
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{
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//t是分正负方向的
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float3 t0 = (boundsMin - rayOrigin) / rayDir;
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float3 t1 = (boundsMax - rayOrigin) / rayDir;
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float3 tmin = min(t0, t1);
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float3 tmax = max(t0, t1);
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//左右上下的面因取最小值得到的都是负值，必然取到正面的值
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float dstA = max(max(tmin.x, tmin.y), tmin.z);
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float dstB = min(tmax.x, min(tmax.y, tmax.z));
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float dstToBox = max(0, dstA);
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float dstInsideBox = max(0, dstB - dstToBox);
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//返回摄像机到包围盒的距离，穿过包围盒内部的距离
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return float2(dstToBox, dstInsideBox);
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}
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float RandomRange(float2 Seed, float Min, float Max)
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{
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float randomno = frac(sin(dot(Seed, float2(12.9898, 78.233)))*43758.5453);
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float Out = lerp(Min, Max, randomno);
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return Out;
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}
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float3 _BoundMin;
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float3 _BoundMax;
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float _J;
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half4 frag (Varyings i) : SV_Target
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{
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_J=24;
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float depth=SampleSceneDepth(i.uv);
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float3 wpos=ComputeWorldSpacePosition(i.uv, depth,UNITY_MATRIX_I_VP);
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//世界空间下从当前点指向摄像机的方向
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float3 dir= normalize(_WorldSpaceCameraPos-wpos);
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float l1=length(_WorldSpaceCameraPos-wpos);
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float2 result=rayBoxDst(_BoundMin,_BoundMax,_WorldSpaceCameraPos.xyz,-dir);
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float dstToBox=result.x;
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float dstInSideBox=result.y;
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//主要dir的方向不然得到的点是错的
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float3 startPos=_WorldSpaceCameraPos.xyz-dir*dstToBox-dir*dstInSideBox;
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//float3 endPos=_WorldSpaceCameraPos.xyz-dir*dstToBox.x;
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float l2=dstToBox+dstInSideBox;
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uint index = (uint(i.uv.x*_ScreenSize.x) % 4) * 4 + uint(i.uv.y*_ScreenSize.y) % 4;
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float jitter =Remap( dither[index],0,1,0.5,1);//*RandomRange(i.uv,0.96,1.04)
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//在AABB包围盒中就使用固定间隔步进,按固定次数步进（视觉效果比按固定距离步进性能更好）
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float d=0;
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float3 currpos=0;
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int Count=24;
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if(l1>l2)
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{
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d=dstInSideBox/_J*RandomRange(i.uv,0.97,1.03);//*RandomRange(i.uv,0.96,1.04);
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Count=dstInSideBox/d;
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currpos=startPos;
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}
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else
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{
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float l=l1-dstToBox;
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d=l/_J*RandomRange(i.uv,0.97,1.03);//*RandomRange(i.uv,0.96,1.04);
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Count=l/d;
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currpos=wpos;
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}
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//穿过AABB包围盒的距离为0时说明光线没有穿过体积光区域，不需要进行后续计算
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if( dstToBox>l1 || dstInSideBox==0) return 0;
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float total=0;
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UNITY_LOOP
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for(int j=0;j<Count;j++)
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{
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//if(length(currpos-_WorldSpaceCameraPos)<0.01 || total>1) break;
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float shadow=Getshadow(currpos);
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total+=shadow*1/Count;
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//添加抖动
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uint index = (uint(i.uv.x*_ScreenSize.x) % 4) * 4 + uint(i.uv.y*_ScreenSize.y) % 4;
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float jitter = Remap( dither[index],0,1,0.5,1);//dither[index];
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currpos+=dir*d;//*jitter;
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}
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//total=saturate(total)*pow(min(dstInSideBox*0.3,2),1);
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total=(total/5*Count*d);
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total=min(total,4);
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return total.xxxx;
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}
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ENDHLSL
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//光线步进
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Pass
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{
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HLSLPROGRAM
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#pragma vertex vert
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#pragma fragment frag
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ENDHLSL
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}
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//高斯模糊-双边过滤
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Pass
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{
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HLSLPROGRAM
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#pragma vertex vert
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#pragma fragment fragBlur
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ENDHLSL
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}
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//合并
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Pass
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{
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HLSLPROGRAM
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#pragma vertex vert
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#pragma fragment fragBlend
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ENDHLSL
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}
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//快速模糊
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Pass
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{
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HLSLPROGRAM
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#pragma vertex vert
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#pragma fragment fragBlurFast
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ENDHLSL
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}
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//快速模糊
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Pass
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{
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HLSLPROGRAM
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#pragma vertex vert
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#pragma fragment fragBlurFast2
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ENDHLSL
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}
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}
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}
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