Question Liquid in Bottle Shader Giving Error in URP

Hello everyone, first of all, I apologize for any mistakes as this is my first post on this forum. I want to use a water shader that I saw on YouTube in my own URP project. However, I'm getting an error message saying: "Shader properties can't be added to this global property sheet. Trying to add _GrabTexture_HDR". I tried options like converting to URP from the Edit tab, but I couldn't get any results. Where exactly is the problem?

Code (CSharp):

1. Shader "TNTC/LiquidInBottle"{
2.     Properties{
3.         _MainTex ("Texture", 2D) = "white" {}
4.         _Color ("Color", Color) = (1,1,1,1)
5.         _Glossiness("Smoothness", Range(0,1)) = 0.5
6.         _Metallic ("Metallic", Range(0,1)) = 0.0
7.  
8.         _BumpMap ("Top Normal Map", 2D) = "bump" {}
9.         _BumpStrenght("Top Normal Strenght", float) = 1
10.         _BumpMapInner ("Inner Normal Map", 2D) = "bump" {}
11.         _BumpStrenghtInner("Inner Normal Strenght", float) = 1
12.         _TopColor("Top Section Color", Color) = (1,1,1,1)
13.  
14.         _Ruffle("Ruffle", float) = 10
15.         _PlanePosition("PlanePosition", Vector) = (0,0,0,1)
16.         _PlaneNormal("PlaneNormal", Vector) = (0,1,0,0)
17.  
18.  
19.         [IntRange] _StencilValue ("Stencil Value", Range(0,255)) = 255
20.     }
21.  
22.     SubShader {
23.         Tags {"Queue"="Geometry"}
24.  
25.         CGINCLUDE
26.  
27.         float3 _PlaneNormal;
28.         float3 _PlanePosition;
29.         float3 _Inertia;
30.         float _Ruffle;
31.  
32.         bool checkVisibility(float3 worldPos){
33.             float dotProd = dot(worldPos - _PlanePosition, _PlaneNormal);
34.             float activityX = clamp(_Inertia.x, 0, 1);
35.             float activityZ = clamp(_Inertia.z, 0, 1);
36.             dotProd += (.5/_Ruffle * sin(activityX * _Ruffle * (worldPos.x + _Time.x)));
37.             dotProd += (.5/_Ruffle * cos(activityZ * _Ruffle * (worldPos.z + _Time.x)));
38.             return dotProd > 0;
39.         }
40.  
41.         ENDCG
42.  
43.         GrabPass{
44.             "_GrabTexture"
45.         }
46.  
47.         Stencil{
48.             Ref [_StencilValue]
49.             CompBack Always
50.             PassBack Replace
51.  
52.             CompFront Always
53.             PassFront Zero
54.         }
55.  
56.      
57.         Cull Front
58.         CGPROGRAM
59.         #pragma surface surf Standard addshadow
60.         #pragma vertex vert
61.         #pragma target 3.0
62.  
63.         struct Input {
64.             half2 uv_MainTex;
65.             float3 worldPos;
66.             float4 screenPos;
67.             float3 normal;
68.             float3 viewDir;
69.             float3 worldNormal;
70.             float4 grabUV;
71.             INTERNAL_DATA
72.         };
73.  
74.         sampler2D _MainTex;
75.         sampler2D _BumpMap;
76.         sampler2D _GrabTexture;
77.         fixed4 _Color;
78.         fixed4 _TopColor;
79.         float _BumpStrenght;
80.         half _Glossiness;
81.         half _Metallic;
82.         float _RotationSpeed;
83.  
84.         void vert (inout appdata_full v, out Input o) {
85.             UNITY_INITIALIZE_OUTPUT(Input,o);
86.             float4 hpos = UnityObjectToClipPos (v.vertex);
87.             o.grabUV = ComputeGrabScreenPos(hpos);
88.         }
89.  
90.         void surf(Input IN, inout SurfaceOutputStandard o){
91.             if (checkVisibility(IN.worldPos))discard;
92.          
93.             float2 screenUV = IN.screenPos.xy / IN.screenPos.w;
94.             screenUV *= float2(8,6);
95.  
96.             float4 background = tex2Dproj( _GrabTexture, IN.grabUV) * _TopColor;
97.             o.Albedo = lerp(background.rgb, _TopColor.rgb, _TopColor.a);
98.  
99.             half3 worldT = WorldNormalVector(IN, half3(1,0,0));
100.             half3 worldB = WorldNormalVector(IN, half3(0,1,0));
101.             half3 worldN = WorldNormalVector(IN, half3(0,0,1));
102.             half3x3 world2Tangent = half3x3(worldT, worldB, worldN);
103.      
104.             float3 n = UnpackScaleNormal(tex2D (_BumpMap, screenUV), _BumpStrenght);
105.             n = mul(world2Tangent, n);
106.             o.Normal = mul(world2Tangent, _PlaneNormal) + n;
107.             o.Metallic = _Metallic;
108.             o.Smoothness = _Glossiness;
109.         }
110.         ENDCG
111.      
112.         Cull Back
113.  
114.         CGPROGRAM
115.         #pragma surface surf Standard addshadow
116.         #pragma vertex vert
117.         #pragma target 3.0
118.  
119.         sampler2D _MainTex;
120.         sampler2D _BumpMapInner;
121.         sampler2D _GrabTexture;
122.         float _BumpStrenghtInner;
123.  
124.         struct Input {
125.             float2 uv_MainTex;
126.             float2 uv_BumpMapInner;
127.             float3 worldPos;
128.             float4 screenPos;
129.             float4 grabUV;
130.         };
131.  
132.         half _Glossiness;
133.         half _Metallic;
134.         fixed4 _Color;
135.         fixed4 _TopColor;
136.  
137.         void vert (inout appdata_full v, out Input o) {
138.             UNITY_INITIALIZE_OUTPUT(Input,o);
139.             float4 hpos = UnityObjectToClipPos (v.vertex);
140.             o.grabUV = ComputeGrabScreenPos(hpos);
141.         }
142.  
143.  
144.         void surf(Input IN, inout SurfaceOutputStandard o) {
145.             if (checkVisibility(IN.worldPos)){
146.                 discard;
147.             }
148.  
149.             float4 background = tex2Dproj( _GrabTexture, IN.grabUV) * _Color;
150.             o.Albedo = lerp(background.rgb, _Color.rgb, _Color.a);
151.          
152.             o.Metallic = _Metallic;
153.             o.Smoothness = _Glossiness;
154.             o.Normal = UnpackScaleNormal (tex2D (_BumpMapInner, IN.uv_BumpMapInner), _BumpStrenghtInner);
155.         }
156.         ENDCG
157.  
158.     }
159. }
160.  
161.  

 

I noticed that this is a surface shader (see #pragma surface) which isn't compatible with URP.
I'm not directly sure what the error message is, but you might have better luck rebuilding the shader manually in the Shader Graph.

 

I can’t rebuild manually in shader graph,
do you have any other advice?

 

Grap pass isn't in URP. Opaque texture is. Not sure how to implement it in text shaders

 

Since the shader queue is set to geometry (2000), I think you can replace the grab pass texture with URP's opaque texture.

URP opaque texture can be sampled with scene color node in shader graph or a global texture named "_CameraOpaqueTexture" after opaque rendering, so the material should be set to transparent if you'd like to sample it.

There two passes in the original shader. If you'd like to recreate it in shader graph, you'll need to assign two materials to the mesh. For text shaders, you can use

Tags { "LightMode" = "UniversalForwardOnly" }

for the first pass, and

Tags { "LightMode" = "SRPDefaultUnlit" }

for the second.