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Why is Global Fog flipping image upside-down?
I installed the latest version of Unity (5.5.0) and re-imported Global Fog effect from the Standard Assets. It was working just fine before, but after the re-import it is flipping the image upside-down when I build the game (Target Platform: Windows).
The problem is related to the Global Fog shader. I saw this document https://docs.unity3d.com/Manual/SL-PlatformDifferences.html and it says that I have to standardize the the coordinates by manually flipping the image, using the following code sample:
if UNITY_UV_STARTS_AT_TOP
f (_MainTex_TexelSize.y < 0) uv.y = 1-uv.y; #endif
But the shader is already using it. Here it isthe shader script:
Shader "Hidden/GlobalFog" { Properties { _MainTex ("Base (RGB)", 2D) = "black" {} }
CGINCLUDE
#include "UnityCG.cginc"
uniform sampler2D _MainTex;
uniform sampler2D_float _CameraDepthTexture;
// x = fog height
// y = FdotC (CameraY-FogHeight)
// z = k (FdotC > 0.0)
// w = a/2
uniform float4 _HeightParams;
// x = start distance
uniform float4 _DistanceParams;
int4 _SceneFogMode; // x = fog mode, y = use radial flag
float4 _SceneFogParams;
#ifndef UNITY_APPLY_FOG
half4 unity_FogColor;
half4 unity_FogDensity;
#endif
uniform float4 _MainTex_TexelSize;
// for fast world space reconstruction
uniform float4x4 _FrustumCornersWS;
uniform float4 _CameraWS;
struct appdata_fog
{
float4 vertex : POSITION;
half2 texcoord : TEXCOORD0;
};
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float2 uv_depth : TEXCOORD1;
float4 interpolatedRay : TEXCOORD2;
};
v2f vert (appdata_fog v)
{
v2f o;
v.vertex.z = 0.1;
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
o.uv = v.texcoord.xy;
o.uv_depth = v.texcoord.xy;
#if UNITY_UV_STARTS_AT_TOP
if (_MainTex_TexelSize.y < 0)
o.uv.y = 1-o.uv.y;
#endif
int frustumIndex = v.texcoord.x + (2 * o.uv.y);
o.interpolatedRay = _FrustumCornersWS[frustumIndex];
o.interpolatedRay.w = frustumIndex;
return o;
}
// Applies one of standard fog formulas, given fog coordinate (i.e. distance)
half ComputeFogFactor (float coord)
{
float fogFac = 0.0;
if (_SceneFogMode.x == 1) // linear
{
// factor = (end-z)/(end-start) = z * (-1/(end-start)) + (end/(end-start))
fogFac = coord * _SceneFogParams.z + _SceneFogParams.w;
}
if (_SceneFogMode.x == 2) // exp
{
// factor = exp(-density*z)
fogFac = _SceneFogParams.y * coord; fogFac = exp2(-fogFac);
}
if (_SceneFogMode.x == 3) // exp2
{
// factor = exp(-(density*z)^2)
fogFac = _SceneFogParams.x * coord; fogFac = exp2(-fogFac*fogFac);
}
return saturate(fogFac);
}
// Distance-based fog
float ComputeDistance (float3 camDir, float zdepth)
{
float dist;
if (_SceneFogMode.y == 1)
dist = length(camDir);
else
dist = zdepth * _ProjectionParams.z;
// Built-in fog starts at near plane, so match that by
// subtracting the near value. Not a perfect approximation
// if near plane is very large, but good enough.
dist -= _ProjectionParams.y;
return dist;
}
// Linear half-space fog, from https://www.terathon.com/lengyel/Lengyel-UnifiedFog.pdf
float ComputeHalfSpace (float3 wsDir)
{
float3 wpos = _CameraWS + wsDir;
float FH = _HeightParams.x;
float3 C = _CameraWS;
float3 V = wsDir;
float3 P = wpos;
float3 aV = _HeightParams.w * V;
float FdotC = _HeightParams.y;
float k = _HeightParams.z;
float FdotP = P.y-FH;
float FdotV = wsDir.y;
float c1 = k * (FdotP + FdotC);
float c2 = (1-2*k) * FdotP;
float g = min(c2, 0.0);
g = -length(aV) * (c1 - g * g / abs(FdotV+1.0e-5f));
return g;
}
half4 ComputeFog (v2f i, bool distance, bool height) : SV_Target
{
half4 sceneColor = tex2D(_MainTex, UnityStereoTransformScreenSpaceTex(i.uv));
// Reconstruct world space position & direction
// towards this screen pixel.
float rawDepth = SAMPLE_DEPTH_TEXTURE(_CameraDepthTexture, UnityStereoTransformScreenSpaceTex(i.uv_depth));
float dpth = Linear01Depth(rawDepth);
float4 wsDir = dpth * i.interpolatedRay;
float4 wsPos = _CameraWS + wsDir;
// Compute fog distance
float g = _DistanceParams.x;
if (distance)
g += ComputeDistance (wsDir, dpth);
if (height)
g += ComputeHalfSpace (wsDir);
// Compute fog amount
half fogFac = ComputeFogFactor (max(0.0,g));
// Do not fog skybox
if (dpth == _DistanceParams.y)
fogFac = 1.0;
//return fogFac; // for debugging
// Lerp between fog color & original scene color
// by fog amount
return lerp (unity_FogColor, sceneColor, fogFac);
}
ENDCG
SubShader { ZTest Always Cull Off ZWrite Off Fog { Mode Off }
// 0: distance + height
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
half4 frag (v2f i) : SV_Target { return ComputeFog (i, true, true); }
ENDCG
}
// 1: distance
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
half4 frag (v2f i) : SV_Target { return ComputeFog (i, true, false); }
ENDCG
}
// 2: height
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
half4 frag (v2f i) : SV_Target { return ComputeFog (i, false, true); }
ENDCG
}
}
Fallback off
}
What should I do to fix this issue? Please Help! Thank You!
Answer by kornica3d · Feb 26, 2017 at 06:28 PM
Hey there. Its a known bug. There is a thread where they have a solution - you just have to replace your GlobalFog file with earlier one, or you can update your unity to latest version...
Answer by Eimantas1 · Jun 13, 2017 at 07:00 PM
Although the fog in 5.4 is very crappy and does not even affect my grass :/
Your answer
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