Alpha Fade Surface Shader Example

Hi,

I am trying to create a custom surface shader that generates a shadowcaster with the fade behaviour, however it is not working.

Here is Unity's Standard shader with the rendering mode to fade:



And here is the result of the shader below:



Note that all I have done is create a new Surface Shader in the Assets dialogue, disable the fallback and instead add the shadow and alpha pragmas as per the docs.

I have attempted to set blending modes, queues, etc but these do not make any difference. Note above that both planes are translucent - the mesh itself is rendering correctly in both images, the only difference is it's not casting a translucent shadow in the second.

Code (csharp):

1.  
2. Shader "Custom/NewSurfaceShader"
3. {
4.     Properties
5.     {
6.         _Color ("Color", Color) = (1,1,1,1)
7.         _MainTex ("Albedo (RGB)", 2D) = "white" {}
8.         _Glossiness ("Smoothness", Range(0,1)) = 0.5
9.         _Metallic ("Metallic", Range(0,1)) = 0.0
10.     }
11.     SubShader
12.     {
13.         Tags { "RenderType"="Opaque" }
14.         LOD 200
15.  
16.         CGPROGRAM
17.         // Physically based Standard lighting model, and enable shadows on all light types
18.         #pragma surface surf Standard fullforwardshadows addshadow alpha:fade
19.  
20.         // Use shader model 3.0 target, to get nicer looking lighting
21.         #pragma target 3.0
22.  
23.         sampler2D _MainTex;
24.  
25.         struct Input
26.         {
27.             float2 uv_MainTex;
28.         };
29.  
30.         half _Glossiness;
31.         half _Metallic;
32.         fixed4 _Color;
33.  
34.         // Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
35.         // See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
36.         // #pragma instancing_options assumeuniformscaling
37.         UNITY_INSTANCING_BUFFER_START(Props)
38.             // put more per-instance properties here
39.         UNITY_INSTANCING_BUFFER_END(Props)
40.  
41.         void surf (Input IN, inout SurfaceOutputStandard o)
42.         {
43.             // Albedo comes from a texture tinted by color
44.             fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
45.             o.Albedo = c.rgb;
46.             // Metallic and smoothness come from slider variables
47.             o.Metallic = _Metallic;
48.             o.Smoothness = _Glossiness;
49.             o.Alpha = c.a;
50.         }
51.         ENDCG
52.     }
53.     //FallBack "Diffuse"
54. }
55.  

Where can I find an example for creating the fade behaviour seen in the standard shader?