Question Standard to URP Surface Shader Conversion

Hi Everyone,

I have a basic Standard Pipeline shader that does not work in URP. It's very basic from what I can tell, but since I am so new to shaders, I have no idea where to even start with trying to get this working in URP. Hoping someone here can give me some pointers.

This shader came from an asset I bought a while back. It gets applied to materials used for graffiti, wall stains, dirt transfers, etc. From what I can tell, it uses another texture to "blend" each fragment color and sets the alpha.

I'm hoping someone can point me in the right direction...

Code (CSharp):

1. Shader "Decals/PBRDecals" {
2.     Properties {
3.         _Color("Main Color", Color) = (1,1,1,1)
4.         _MainTex("Base (RGB) Trans (A)", 2D) = "white" {}
5.         _BumpMap("Normalmap", 2D) = "bump" {}
6.         _BumpScale("Normalmap strength", Range(0.0, 10.0)) = 1.0
7.         _Glossiness("Glossiness", 2D) = "white" {}
8.         _Gloss("Gloss", Range(0.0, 1.0)) = 1.0
9.         _Metallic("Metallic", Range(0.0, 1.0)) = 0.0
10.     }
11.     SubShader {
12.         Tags { "RenderType"="Transparent" "IgnoreProjector" = "True" "Queue" = "AlphaTest" }
13.         LOD 200
14.        
15.         //Blend SrcAlpha OneMinusSrcAlpha
16.  
17.         CGPROGRAM
18.         // Physically based Standard lighting model, and enable shadows on all light types
19.         #pragma surface surf Standard fullforwardshadows decal:blend//alpha:blend
20.  
21.         // Use shader model 3.0 target, to get nicer looking lighting
22.         #pragma target 3.0
23.  
24.         sampler2D _MainTex;
25.         sampler2D _BumpMap;
26.         sampler2D _Glossiness;
27.         float _Gloss, _Metallic, _BumpScale;
28.         fixed4 _Color;
29.  
30.         struct Input {
31.             float2 uv_MainTex;
32.             float2 uv_BumpMap;
33.             float4 color: Color;
34.         };
35.  
36.         void surf (Input IN, inout SurfaceOutputStandard o) {
37.             fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color  * IN.color;
38.             o.Albedo = c.rgb;
39.             o.Alpha = c.a;
40.             o.Normal = UnpackScaleNormal(tex2D(_BumpMap, IN.uv_BumpMap), _BumpScale);
41.             half4 glossMap = tex2D(_Glossiness, IN.uv_MainTex);
42.             o.Metallic = _Metallic;
43.             o.Smoothness = glossMap.r * _Gloss;
44.         }
45.         ENDCG
46.     }
47.     FallBack "Decal/Transparent Diffuse"
48. }