Hi,
I have a vert/frag shader that does not use any surf calls, so should work in LWRP but is not. It also doesn’t throw any errors. How would one recommend investigating it?
Material 
In Scene (should be transparent, but is gray, yet not pink) 
Shader Code
// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'
Shader "QFSW/Blur"
{
Properties
{
_Color("Main Color", Color) = (1,1,1,1)
_MainTex("Tint Color (RGB)", 2D) = "white" {}
_Radius("Radius", Range(0, 20)) = 1
}
Category
{
Tags{ "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Opaque" }
SubShader{
GrabPass{
Tags{ "LightMode" = "Always" }
}
Pass{
Tags{ "LightMode" = "Always" }
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
struct appdata_t
{
float4 vertex : POSITION;
float2 texcoord: TEXCOORD0;
fixed4 color : COLOR;
};
struct v2f
{
float4 vertex : POSITION;
float4 uvgrab : TEXCOORD0;
fixed4 color : COLOR;
};
v2f vert(appdata_t v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
#if UNITY_UV_STARTS_AT_TOP
float scale = -1.0;
#else
float scale = 1.0;
#endif
o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y*scale) + o.vertex.w) * 0.5;
o.uvgrab.zw = o.vertex.zw;
o.color = v.color;
return o;
}
sampler2D _GrabTexture;
float4 _GrabTexture_TexelSize;
uniform float _Radius;
uniform float _BlurMultiplier = 1;
half4 frag(v2f i) : COLOR
{
_Radius *= _BlurMultiplier;
_Radius *= i.color.a;
half4 sum = half4(0,0,0,0);
#define GRABPIXEL(weight, kernelx) tex2Dproj(_GrabTexture, UNITY_PROJ_COORD(float4(i.uvgrab.x + _GrabTexture_TexelSize.x * kernelx * _Radius, i.uvgrab.y, i.uvgrab.z, i.uvgrab.w))) * weight
sum += GRABPIXEL(0.05, -4.0);
sum += GRABPIXEL(0.09, -3.0);
sum += GRABPIXEL(0.12, -2.0);
sum += GRABPIXEL(0.15, -1.0);
sum += GRABPIXEL(0.18, 0.0);
sum += GRABPIXEL(0.15, +1.0);
sum += GRABPIXEL(0.12, +2.0);
sum += GRABPIXEL(0.09, +3.0);
sum += GRABPIXEL(0.05, +4.0);
return sum;
}
ENDCG
}
GrabPass
{
Tags{ "LightMode" = "Always" }
}
Pass{
Tags{ "LightMode" = "Always" }
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
struct appdata_t
{
float4 vertex : POSITION;
float2 texcoord: TEXCOORD0;
fixed4 color : COLOR;
};
struct v2f {
float4 vertex : POSITION;
float4 uvgrab : TEXCOORD0;
fixed4 color : COLOR;
};
v2f vert(appdata_t v) {
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
#if UNITY_UV_STARTS_AT_TOP
float scale = -1.0;
#else
float scale = 1.0;
#endif
o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y*scale) + o.vertex.w) * 0.5;
o.uvgrab.zw = o.vertex.zw;
o.color = v.color;
return o;
}
sampler2D _GrabTexture;
float4 _GrabTexture_TexelSize;
uniform float _Radius;
uniform float _BlurMultiplier = 1;
half4 frag(v2f i) : COLOR{
_Radius *= _BlurMultiplier;
_Radius *= i.color.a;
half4 sum = half4(0,0,0,0);
#define GRABPIXEL(weight,kernely) tex2Dproj( _GrabTexture, UNITY_PROJ_COORD(float4(i.uvgrab.x, i.uvgrab.y + _GrabTexture_TexelSize.y * kernely*_Radius, i.uvgrab.z, i.uvgrab.w))) * weight
sum += GRABPIXEL(0.05, -4.0);
sum += GRABPIXEL(0.09, -3.0);
sum += GRABPIXEL(0.12, -2.0);
sum += GRABPIXEL(0.15, -1.0);
sum += GRABPIXEL(0.18, 0.0);
sum += GRABPIXEL(0.15, +1.0);
sum += GRABPIXEL(0.12, +2.0);
sum += GRABPIXEL(0.09, +3.0);
sum += GRABPIXEL(0.05, +4.0);
return sum;
}
ENDCG
}
GrabPass{
Tags{ "LightMode" = "Always" }
}
Pass{
Tags{ "LightMode" = "Always" }
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
struct appdata_t {
float4 vertex : POSITION;
float2 texcoord: TEXCOORD0;
};
struct v2f
{
float4 vertex : POSITION;
float4 uvgrab : TEXCOORD0;
float2 uvmain : TEXCOORD1;
};
float4 _MainTex_ST;
v2f vert(appdata_t v) {
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
#if UNITY_UV_STARTS_AT_TOP
float scale = -1.0;
#else
float scale = 1.0;
#endif
o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y*scale) + o.vertex.w) * 0.5;
o.uvgrab.zw = o.vertex.zw;
o.uvmain = TRANSFORM_TEX(v.texcoord, _MainTex);
return o;
}
fixed4 _Color;
sampler2D _GrabTexture;
float4 _GrabTexture_TexelSize;
sampler2D _MainTex;
half4 frag(v2f i) : COLOR
{
half4 col = tex2Dproj(_GrabTexture, UNITY_PROJ_COORD(i.uvgrab));
half4 tint = tex2D(_MainTex, i.uvmain) * _Color;
return col * tint;
}
ENDCG
}
}
}
}
