Question URP Custom Sprite Shader

I'm expermenting with Unity 2020.1's URP to see if it's worth upgrading my project but so far I have had some difficulties trying to get my custom shader to work with the URP.


This is the shader effect I have, where each unit (2D SpriteRenderers) are colored silhouettes when occluded by objects/3D meshes, colors based on whichever alliance they belong to. The shader itself is a customized version of Unity's Sprite Shader, I wrote an extra pass with custom fields to create the X-Ray effect (with a lot of tinkering around with ZDepth and Stencil to get this to work). The colors are set during the initialization state of the game and can be changed via events.

As far as I know, my shader doesn't work in URP since it uses forward rather than deferred rendering. So my only option was to follow this tutorial by Brackey's:

In order to get this:

But this doesn't really cut it for me as it simply uses a shared shader and renders all occluded parts of a sprite using said shader, which doesn't allow for any customization whatsoever. The only way I could think of to somehow achieve the effect of my custom shader is to somehow have the shader I made for URP take in a variable of the current object being rendered as the alliance color to and render the silhouette with it. But I don't think there is anyway for me to do this.

If anyone has any ideas, it'll be much appreciated.

Here's the custom shader if anyone's interested:

Code (CSharp):

1. Shader "Custom/Sprite(Unit)"
2. {
3.     Properties
4.     {
5.         _MainTex ("Main Texture", 2D) = "white" {}
6.         _Color ("Color", Color) = (1,1,1,1)
7.      
8.         PixelSnap ("Pixel snap", Float) = 0
9.         _AlphaTex ("External Alpha", 2D) = "white" {}
10.         _EnableExternalAlpha ("Enable External Alpha", Float) = 0
11.      
12.         _ZWrite ("Depth Write", Float) = 0.0
13.         _Cutoff ("Depth alpha cutoff", Range(0,1)) = 0.0
14.         _ShadowAlphaCutoff ("Shadow alpha cutoff", Range(0,1)) = 0.3
15.         _CustomRenderQueue ("Custom Render Queue", Float) = 0.0
16.      
17.         _OverlayColor ("Overlay Color", Color) = (0,0,0,0)
18.         _Hue("Hue", Range(-0.5,0.5)) = 0.0
19.         _Saturation("Saturation", Range(0,2)) = 1.0  
20.         _Brightness("Brightness", Range(0,2)) = 1.0  
21.      
22.         _BlendTex ("Blend Texture", 2D) = "white" {}
23.         _BlendAmount ("Blend", Range(0,1)) = 0.0
24.      
25.         _EmissionMap("Emission Map", 2D) = "black" {}
26.         [HDR] _EmissionColor("Emission Color", Color) = (0, 0, 0)
27.  
28.         [HideInInspector] _SrcBlend ("__src", Float) = 1.0
29.         [HideInInspector] _DstBlend ("__dst", Float) = 0.0
30.         [HideInInspector] _RenderQueue ("__queue", Float) = 0.0
31.         [HideInInspector] _Cull ("__cull", Float) = 0.0
32.  
33.         _RenderQueue("Render Queue", Float) = 0.0
34.  
35.         _Matrix1("matrix", vector) = (1,1,1,1)
36.         _Matrix2("matrix", vector) = (1,1,1,1)
37.         _Matrix3("matrix", vector) = (1,1,1,1)
38.  
39.         // Custom
40.         [Toggle] _Frozen ("Frozen Status", Int) = 0
41.  
42.  
43.         _OutlineMode ("Outline Mode", Int) = 0
44.         _AllianceColor ("Alliance Color", Color) = (0, 0, 0, 1)
45.     }
46.  
47.  
48.     SubShader
49.     {
50.         Tags
51.         {
52.             "Queue" = "Transparent"
53.             "RenderType" = "Sprite"
54.             "AlphaDepth" = "False"
55.             "CanUseSpriteAtlas" = "True"
56.             "IgnoreProjector" = "True"
57.         }
58.         LOD 100
59.  
60.         // Main Pass
61.         Pass
62.         {
63.             Blend[_SrcBlend][_DstBlend]
64.             Lighting Off
65.             ZWrite[_ZWrite]
66.             ZTest LEqual
67.             Cull[_Cull]
68.             Lighting Off
69.  
70.             // Write to stencil
71.             Stencil
72.             {
73.                 Ref 4
74.                 Comp always
75.                 Pass replace
76.                 ZFail keep
77.                 Fail replace
78.             }
79.  
80.             CGPROGRAM
81.                 #pragma shader_feature _ _ALPHABLEND_ON _ALPHAPREMULTIPLY_ON _ADDITIVEBLEND _ADDITIVEBLEND_SOFT _MULTIPLYBLEND _MULTIPLYBLEND_X2
82.                 #pragma shader_feature _ALPHA_CLIP
83.                 #pragma shader_feature _TEXTURE_BLEND
84.                 #pragma shader_feature _COLOR_ADJUST
85.                 #pragma shader_feature _FOG
86.  
87.                 #pragma fragmentoption ARB_precision_hint_fastest
88.                 #pragma multi_compile_fog
89.                 #pragma multi_compile_instancing
90.                 #pragma multi_compile _ PIXELSNAP_ON
91.                 #pragma multi_compile _ ETC1_EXTERNAL_ALPHA
92.  
93.                 #pragma vertex vert
94.                 #pragma fragment frag
95.  
96.                 #include "../Shaders/shaders_includes/SpriteShaders/CGIncludes/SpriteUnlit.cginc"
97.             ENDCG
98.         }
99.          
100.         // Shadow
101.         Pass
102.         {
103.             Name "ShadowCaster"
104.             Tags { "LightMode" = "ShadowCaster" }
105.             Offset 1, 1
106.  
107.             Fog { Mode Off }
108.             ZWrite On
109.             ZTest LEqual
110.             Cull Off
111.             Lighting Off
112.  
113.             CGPROGRAM
114.                 #pragma fragmentoption ARB_precision_hint_fastest
115.                 #pragma multi_compile_shadowcaster
116.                 #pragma multi_compile_instancing
117.                 #pragma multi_compile _ PIXELSNAP_ON
118.                 #pragma multi_compile _ ETC1_EXTERNAL_ALPHA
119.  
120.                 #pragma vertex vert
121.                 #pragma fragment frag
122.  
123.                 #include "../Shaders/shaders_includes/SpriteShaders/CGIncludes/SpriteShadows.cginc"
124.  
125.             ENDCG
126.         }
127.      
128.         // X-Ray Shader Pass
129.         Pass
130.         {
131.             Tags{
132.                  "Queue" = "Transparent"
133.                  "AlphaDepth" = "True"
134.             }
135.  
136.             Cull Off
137.             ZWrite off
138.             ZTest always
139.             Stencil
140.             {
141.                 Ref 4
142.                 Comp notequal
143.                 Pass keep
144.                 Fail keep
145.             }
146.             Blend SrcAlpha OneMinusSrcAlpha
147.          
148.          
149.             CGPROGRAM
150.             #pragma vertex vert
151.             #pragma fragment frag
152.             #include "../Shaders/shaders_includes/SpriteShaders/CGIncludes/ShaderShared.cginc"
153.  
154.             float4 _MainTex_TexelSize;
155.             float4 _AllianceColor;
156.             int _OutlineMode;
157.  
158.             struct v_in {
159.                 float4 vertex : POSITION;
160.                 float4 texcoord : TEXCOORD0;
161.             };
162.  
163.             struct v_out {
164.                 float4 pos : SV_POSITION;
165.                 float2 texcoord : TEXCOORD0;
166.                 fixed4 color : COLOR;
167.             };
168.  
169.             v_out vert(v_in input) {
170.                 v_out output;
171.  
172.                 output.pos = calculateLocalPos(input.vertex);
173.                 output.texcoord = calculateTextureCoord(input.texcoord);
174.  
175.                 return output;
176.             }
177.  
178.             float4 frag(v_out input) : SV_TARGET
179.             {
180.                 // Dead unit, then skips this pass
181.                 if (_OutlineMode == 2)
182.                     discard;
183.  
184.                 fixed4 textureColor = calculateTexturePixel(input.texcoord.xy);
185.                 ALPHA_CLIP_COLOR(texureColor, input.color);
186.  
187.                 if (textureColor.a < 0.1f)
188.                     discard;
189.  
190.                 if (_OutlineMode == 0) {
191.                     if (textureColor.a < 0.2f)
192.                         discard;
193.                     return _AllianceColor;
194.                 }
195.  
196.                 // Outline only
197.                 if (textureColor.a != 0) {
198.                     // Get the neighbouring four pixels.
199.                     fixed4 pixelUp        =    tex2D(_MainTex, input.texcoord.xy + float2(0, _MainTex_TexelSize.y));
200.                     fixed4 pixelDown    =    tex2D(_MainTex, input.texcoord.xy - float2(0, _MainTex_TexelSize.y));
201.                     fixed4 pixelRight    =    tex2D(_MainTex, input.texcoord.xy + float2(_MainTex_TexelSize.x, 0));
202.                     fixed4 pixelLeft    =    tex2D(_MainTex, input.texcoord.xy - float2(_MainTex_TexelSize.x, 0));
203.  
204.                     // If one of the neighbouring pixels is invisible, render outline.
205.                     if (pixelUp.a * pixelDown.a * pixelRight.a * pixelLeft.a == 0) {
206.                         textureColor.rgba = fixed4(1, 1, 1, textureColor.a) * _AllianceColor;
207.                     }
208.                     else {
209.                         discard;
210.                     }
211.                 }
212.  
213.  
214.                 return textureColor;
215.             }
216.  
217.             ENDCG
218.         }
219.     }
220.  
221.     CustomEditor "SpriteShaderGUI"
222. }
223.