How do you use UNITY_REQUIRE_ADVANCED_BLEND?

I want to use the SoftLight BlendOp. The documentation here is unclear though. https://docs.unity3d.com/ScriptReference/Rendering.BlendOp.html

(Also there's a typo which writes "ADVANDED")

I type this into my shader after "Shader "SHADERNAME" { " :

UNITY_REQUIRE_ADVANCED_BLEND(SoftLight)

But I get this error "Shader error in 'BG_Layer_Advanced_2D': Parse error: syntax error, unexpected TVAL_ID at line 4"

Followed by a warning:

"Shader warning in 'BG_Layer_Advanced_2D': Shader is not supported on this GPU (none of subshaders/fallbacks are suitable)"

I was kind of guessing my GPU wouldn't support this but I'm not sure if that's a result of me typing the UNITY_REQUIRE wrong or what.

Here's the not working shader:

Code (CSharp):

1.  
2. Shader "Unlit/TranspUnlitADVANCEDSpriteMesh"
3. {
4.     UNITY_REQUIRE_ADVANCED_BLEND(SoftLight)
5.  
6.     Properties
7.     {
8.         _MainTex ("Texture", 2D) = "white" {}
9.         _Transparency ("Transparency", Range(0,1)) = 0
10.         //SourceMode ("SourceMode",float) = 5
11.         //DestinationMode ("DestinationMode",float) = 10
12.         OpMode ("OpMode", float) = 0 //Add by default, set to advanced things in script. Overrides "Blend" if advanced
13.     }
14.     SubShader
15.     {
16.         Tags { "Queue" = "Transparent"}
17.         BlendOp [OpMode]
18.         Blend SrcAlpha OneMinusSrcAlpha // Regular blend by default
19.         Pass
20.         {
21.        
22.             CGPROGRAM
23.             #pragma vertex vert
24.             #pragma fragment frag
25.            
26.             #include "UnityCG.cginc"
27.  
28.             uniform float _Transparency;
29.             struct appdata
30.             {
31.                 float4 vertex : POSITION;
32.                 float2 uv : TEXCOORD0;
33.             };
34.  
35.             struct v2f
36.             {
37.                 float2 uv : TEXCOORD0;
38.                 float4 vertex : SV_POSITION;
39.             };
40.  
41.             sampler2D _MainTex;
42.             float4 _MainTex_ST;
43.            
44.             v2f vert (appdata v)
45.             {
46.                 v2f o;
47.                 o.vertex = UnityObjectToClipPos(v.vertex);
48.                 o.uv = TRANSFORM_TEX(v.uv, _MainTex);
49.                 return o;
50.             }
51.            
52.             fixed4 frag (v2f i) : SV_Target
53.             {
54.                 fixed4 col = tex2D(_MainTex, i.uv);
55.                 col.a = _Transparency;
56.                 return col;
57.             }
58.             ENDCG
59.         }
60.     }
61. }
62.  

 

Hi! I'm having the same problem and moving it inside the CGPROGRAM block isn't fixing it. Did you get it to work eventually? Do i need to install any package or do something else outside the shader?

 

I was never able to get it to work - I ended up having to code the softlight algorithm into the fragment shader:

Code (CSharp):

1. Shader "Unlit/TranspUnlitADVANCEDSpriteMesh"
2. {
3.  
4.     Properties
5.     {
6.         _MainTex ("Texture", 2D) = "white" {}
7.         _Transparency ("Transparency", Range(0,1)) = 0
8.         _OpMode ("OpMode", int) = 0 //Add by default, set to advanced things in script. Overrides "Blend" if advanced
9.     }
10.     SubShader
11.     {
12.         Tags { "Queue" = "Transparent"}
13.        
14.         GrabPass { }
15.  
16.         Blend One Zero
17.         Pass
18.         {
19.        
20.             CGPROGRAM
21.             #pragma vertex vert
22.             #pragma fragment frag
23.            
24.             #include "UnityCG.cginc"
25.  
26.             uniform float _Transparency;
27.             struct appdata
28.             {
29.                 float4 vertex : POSITION;
30.                 float2 uv : TEXCOORD0;
31.             };
32.  
33.             struct v2f
34.             {
35.                 float2 uv : TEXCOORD0;
36.                 float4 vertex : SV_POSITION; // NOT interpolated
37.                 float4 screenPos: TEXCOORD1; // Interpolated!
38.             };
39.  
40.             sampler2D _MainTex;
41.             float4 _MainTex_ST;
42.             sampler2D _GrabTexture;
43.             uniform int _OpMode;
44.  
45.             v2f vert (appdata v)
46.             {
47.                 v2f o;
48.                 o.vertex = UnityObjectToClipPos(v.vertex);
49.                 o.screenPos = o.vertex;
50.                 o.uv = TRANSFORM_TEX(v.uv, _MainTex);
51.                 return o;
52.             }
53.            
54.             // a = bottom, b = top
55.             fixed4 Overlay(fixed4 a, fixed4 b) {
56.                 fixed4 r = a < .5 ? 2.0 * a * b : 1.0 - 2.0 * (1.0 - a) * (1.0 - b);
57.                 return r;
58.             }
59.  
60.             // Pegtop formula
61.             fixed4 SoftLight(fixed4 a, fixed4 b) {
62.                 fixed4 r = (1 - 2*b)*a*a + 2*b*a;
63.                 return r;
64.             }
65.  
66.             fixed4 frag (v2f i) : SV_Target
67.             {
68.                 fixed4 col = tex2D(_MainTex, i.uv);
69.                 // Clip space, -1 to 1
70.                 float2 grabTexcoord = (i.screenPos.xy + 1)/2; // Converts to UV coords from 0 to 1 that will sample from the grab tex2D
71.                 // the conversion works because the clip space coords of stuff fit to the camera view
72.                 #if UNITY_UV_STARTS_AT_TOP
73.                 grabTexcoord.y = 1.0 - grabTexcoord.y;
74.                 #endif
75.                
76.                 fixed4 grabColor = tex2D(_GrabTexture, grabTexcoord);
77.  
78.                
79.                 col.a *= _Transparency;
80.                 if (_OpMode == 29){ // SoftLight
81.                     col *= col.a;
82.                     col = SoftLight(grabColor,col);
83.                 } else if (_OpMode == 23) { // Overlay
84.                     col *= col.a;
85.                     col = Overlay(grabColor,col);
86.                 } else {
87.                     col = col*col.a + grabColor*(1-col.a);
88.                 }
89.                 return col;
90.             }
91.             ENDCG
92.         }
93.  
94.  
95.  
96.     }
97. }
98.  

 

Did you ever file a bug report?

 

I did not.

 

Could you perhaps? That way it's in the pipeline to get fixed, improving the engine for all.

 

Thank you! I guess I'll do the same inlcuding all the blend modes I need

 

I tried copying the shader you posted before trying to do any modification to it and it gives some console errors that I can't figure out how to fix (it's the first time i use a GrabPass so I'm sorry if it's something obvious), I'd appreciate if you could tell me what's wrong
*EDIT* I think it might be cause I'm on the URP pipeline and the GrabPass doesn't work here