Hi hi folks! I was looking at a shader that used GrabPass to render the scene behind a “transparent” rainy window. It looks like GrabPass is obsolete (it’s been depreciated for awhile it looks like) and my code doesn’t work anymore. Any workarounds on this? Photos of what it should look like vs what it looks like are attached below. Thanks in advance.
Shader "Unlit/Window"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
_Size ("Size", float) = 1
_T("Time", float) = 1
_Distortion("Distortion", range(-5, 5)) = 1
_Blur("Blur", range(0,1)) = 1
}
SubShader
{
Tags { "RenderType"="Opaque" "Queue"="Transparent"}
LOD 100
GrabPass {"_GrabTexture"} //render the scene and call it "_GrabTexture"
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
// make fog work
#pragma multi_compile_fog
#define S(a, b, t) smoothstep(a, b, t) //before it compiles "s" replace with "smoothstep"
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
float4 grabUv : TEXCOORD1;
UNITY_FOG_COORDS(1)
float4 vertex : SV_POSITION;
};
sampler2D _MainTex, _GrabTexture;
float4 _MainTex_ST;
float _Size, _T, _Distortion, _Blur;
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
o.grabUv = UNITY_PROJ_COORD(ComputeGrabScreenPos(o.vertex));
UNITY_TRANSFER_FOG(o,o.vertex);
return o;
}
float N21(float2 p)
{
p = frac(p*float2(123.34, 345.45));
p += dot(p, p + 34.345);
return frac(p.x*p.y);
}
float3 Layer(float2 UV,float t)
{
float2 aspect =float2(2, 1);
float2 uv = UV*_Size*aspect;
uv.y += t *.25;
float2 gv = frac(uv)-.5;
float2 id = floor(uv);
float n = N21(id);
t += n*6.2831; //time by boxes can at most differ by 2pi
float w = UV.y * 10;
float x = (n - .5)*.8;
x += (.4-abs(x))*sin(3 * w)*pow(sin(w), 6)*.45; //stops wiggle if the rain particle is close to edge
float y = -sin(t+sin(t+sin(t)*.5))*.45;
y -= (gv.x-x)*(gv.x-x);
float2 dropPos = (gv - float2(x, y)) / aspect;
float drop = S(.05, .03, length(dropPos));
float2 trailPos = (gv - float2(x, t *.25)) / aspect;
trailPos.y = (frac(trailPos.y * 8)-.5)/8;
float trail = S(.03, .01, length(trailPos)); //dictates size
float fogTrail = S(-.05, .05, dropPos.y);
fogTrail *= S(.5,y,gv.y);
trail *= fogTrail;
fogTrail *= S(.05, .04, abs(dropPos.x));
float2 offs = drop*dropPos + trail*trailPos;
return float3(offs, fogTrail);
}
fixed4 frag (v2f i) : SV_Target
{
float t = fmod(_Time.y + _T, 7200); //reset every two hours
float4 col = 0;
//float rand = i.uv*1.23 + 7.54;
float3 drops = Layer(i.uv, t);
drops += Layer(i.uv*1.23 + 7.54, t);
drops += Layer(i.uv*1.45 + 2.15, t); //add more drops for more rain
float fade = 1-saturate(fwidth(i.uv)*50);
float blur = _Blur * 7 * (1 - drops.z*fade);
col = tex2Dlod(_MainTex, float4(i.uv + drops.xy*_Distortion, 0, blur)); //Takes material from shader
float2 projUv = i.grabUv.xy / i.grabUv.w;
projUv += drops.xy * _Distortion * fade;
blur *= .1;
/*const float numSamples = 4;
float a = N21(i.uv)*6.2831;
for (float i = 0; i < numSamples; i++)
{
float2 offs = float2(sin(a), cos(a)) * blur;
float d = frac(sin((i+1)*546.)*5424.);
d = sqrt(d);
offs *= d;
col = tex2D(_MainTex, projUv+offs);
a++;
}
col /= numSamples;*/
//col *= 0; col+= fade;
return col*.9;
}
ENDCG
}
}
}
