Hi guys, i have some problem with my shader in unity urp, i create an atmosphere like that (cf first picture) then i converted my project into urp and now, i have this things , i show you my shader script :
Shader “Hidden/Atmosphere”
{
Properties
{
_MainTex (“Texture”, 2D) = “white” {}
}
SubShader
{
// No culling or depth
Cull Off ZWrite Off ZTest Always
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include “UnityCG.cginc”
#include “…/Includes/Math.cginc”
//
struct appdata {
float4 vertex : POSITION;
float4 uv : TEXCOORD0;
};
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float3 viewVector : TEXCOORD1;
};
v2f vert (appdata v) {
v2f output;
output.pos = UnityObjectToClipPos(v.vertex);
output.uv = v.uv;
// Camera space matches OpenGL convention where cam forward is -z. In unity forward is positive z.
// (Unity - Scripting API: Camera.cameraToWorldMatrix)
float3 viewVector = mul(unity_CameraInvProjection, float4(v.uv.xy * 2 - 1, 0, -1));
output.viewVector = mul(unity_CameraToWorld, float4(viewVector,0));
return output;
}
float2 squareUV(float2 uv) {
float width = _ScreenParams.x;
float height =_ScreenParams.y;
//float minDim = min(width, height);
float scale = 1000;
float x = uv.x * width;
float y = uv.y * height;
return float2 (x/scale, y/scale);
}
sampler2D _BlueNoise;
sampler2D _MainTex;
sampler2D _BakedOpticalDepth;
//sampler2D _CameraDepthTexture;
UNITY_DECLARE_DEPTH_TEXTURE(_CameraDepthTexture);
float4 params;
float3 dirToSun;
float3 planetCentre;
float atmosphereRadius;
float oceanRadius;
float planetRadius;
// Paramaters
int numInScatteringPoints;
int numOpticalDepthPoints;
float intensity;
float4 scatteringCoefficients;
float ditherStrength;
float ditherScale;
float densityFalloff;
float densityAtPoint(float3 densitySamplePoint) {
float heightAboveSurface = length(densitySamplePoint - planetCentre) - planetRadius;
float height01 = heightAboveSurface / (atmosphereRadius - planetRadius);
float localDensity = exp(-height01 * densityFalloff) * (1 - height01);
return localDensity;
}
float opticalDepth(float3 rayOrigin, float3 rayDir, float rayLength) {
float3 densitySamplePoint = rayOrigin;
float stepSize = rayLength / (numOpticalDepthPoints - 1);
float opticalDepth = 0;
for (int i = 0; i < numOpticalDepthPoints; i ++) {
float localDensity = densityAtPoint(densitySamplePoint);
opticalDepth += localDensity * stepSize;
densitySamplePoint += rayDir * stepSize;
}
return opticalDepth;
}
float opticalDepthBaked(float3 rayOrigin, float3 rayDir) {
float height = length(rayOrigin - planetCentre) - planetRadius;
float height01 = saturate(height / (atmosphereRadius - planetRadius));
float uvX = 1 - (dot(normalize(rayOrigin - planetCentre), rayDir) * .5 + .5);
return tex2Dlod(_BakedOpticalDepth, float4(uvX, height01,0,0));
}
float opticalDepthBaked2(float3 rayOrigin, float3 rayDir, float rayLength) {
float3 endPoint = rayOrigin + rayDir * rayLength;
float d = dot(rayDir, normalize(rayOrigin-planetCentre));
float opticalDepth = 0;
const float blendStrength = 1.5;
float w = saturate(d * blendStrength + .5);
float d1 = opticalDepthBaked(rayOrigin, rayDir) - opticalDepthBaked(endPoint, rayDir);
float d2 = opticalDepthBaked(endPoint, -rayDir) - opticalDepthBaked(rayOrigin, -rayDir);
opticalDepth = lerp(d2, d1, w);
return opticalDepth;
}
float3 calculateLight(float3 rayOrigin, float3 rayDir, float rayLength, float3 originalCol, float2 uv) {
float blueNoise = tex2Dlod(_BlueNoise, float4(squareUV(uv) * ditherScale,0,0));
blueNoise = (blueNoise - 0.5) * ditherStrength;
float3 inScatterPoint = rayOrigin;
float stepSize = rayLength / (numInScatteringPoints - 1);
float3 inScatteredLight = 0;
float viewRayOpticalDepth = 0;
for (int i = 0; i < numInScatteringPoints; i ++) {
float sunRayLength = raySphere(planetCentre, atmosphereRadius, inScatterPoint, dirToSun).y;
float sunRayOpticalDepth = opticalDepthBaked(inScatterPoint + dirToSun * ditherStrength, dirToSun);
float localDensity = densityAtPoint(inScatterPoint);
viewRayOpticalDepth = opticalDepthBaked2(rayOrigin, rayDir, stepSize * i);
float3 transmittance = exp(-(sunRayOpticalDepth + viewRayOpticalDepth) * scatteringCoefficients);
inScatteredLight += localDensity * transmittance;
inScatterPoint += rayDir * stepSize;
}
inScatteredLight *= scatteringCoefficients * intensity * stepSize / planetRadius;
inScatteredLight += blueNoise * 0.01;
// Attenuate brightness of original col (i.e light reflected from planet surfaces)
// This is a hacky mess, TODO: figure out a proper way to do this
const float brightnessAdaptionStrength = 0.15;
const float reflectedLightOutScatterStrength = 3;
float brightnessAdaption = dot (inScatteredLight,1) * brightnessAdaptionStrength;
float brightnessSum = viewRayOpticalDepth * intensity * reflectedLightOutScatterStrength + brightnessAdaption;
float reflectedLightStrength = exp(-brightnessSum);
float hdrStrength = saturate(dot(originalCol,1)/3-1);
reflectedLightStrength = lerp(reflectedLightStrength, 1, hdrStrength);
float3 reflectedLight = originalCol * reflectedLightStrength;
float3 finalCol = reflectedLight + inScatteredLight;
return finalCol;
}
float4 frag (v2f i) : SV_Target
{
float4 originalCol = tex2D(_MainTex, i.uv);
float sceneDepthNonLinear = SAMPLE_DEPTH_TEXTURE(_CameraDepthTexture, i.uv);
float sceneDepth = LinearEyeDepth(sceneDepthNonLinear) * length(i.viewVector);
float3 rayOrigin = _WorldSpaceCameraPos;
float3 rayDir = normalize(i.viewVector);
float dstToOcean = raySphere(planetCentre, oceanRadius, rayOrigin, rayDir);
float dstToSurface = min(sceneDepth, dstToOcean);
float2 hitInfo = raySphere(planetCentre, atmosphereRadius, rayOrigin, rayDir);
float dstToAtmosphere = hitInfo.x;
float dstThroughAtmosphere = min(hitInfo.y, dstToSurface - dstToAtmosphere);
if (dstThroughAtmosphere > 0) {
const float epsilon = 0.0001;
float3 pointInAtmosphere = rayOrigin + rayDir * (dstToAtmosphere + epsilon);
float3 light = calculateLight(pointInAtmosphere, rayDir, dstThroughAtmosphere - epsilon * 2, originalCol, i.uv);
return float4(light, 1);
}
return originalCol;
}
ENDCG
}
}
}
I’m a beginner in unity so i hope you will be able to help me in order to make my atmosphere shader works in urp. Thanks .
