Shadow on a transparent object

Hi
Does anyone know if it's possible to get a shadow on a completely transparent object?
Need to cast a shadow from the 3d character on the sidewalk

 

That should be possible. It would be called a matte shadow and there are various topics on this on the forum.
https://forum.unity3d.com/threads/matte-shadow.14438/

 

It does not work in Unity 5

 

UP

 

This one works for me:

Code (CSharp):

1. Shader "Shadow Collector" {
2.     Properties
3.     {
4.         _Color("Main Color", Color) = (1,1,1,.5)
5.         _ShadowIntensity("Shadow Intensity", Range(0, 1)) = 0.6
6.     }
7.     SubShader
8.     {
9.         Tags{ "Queue" = "AlphaTest" }
10.    
11.         Pass
12.         {
13.             Tags{ "LightMode" = "ForwardBase" }
14.             Cull Back
15.             Blend SrcAlpha OneMinusSrcAlpha
16.             CGPROGRAM
17.             #pragma vertex vert
18.             #pragma fragment frag
19.             #pragma multi_compile_fwdbase
20.             #include "UnityCG.cginc"
21.             #include "AutoLight.cginc"
22.             uniform fixed4  _Color;
23.             uniform float _ShadowIntensity;
24.             struct v2f
25.             {
26.                 float4 pos : SV_POSITION;
27.                 LIGHTING_COORDS(1,2)
28.             };
29.             v2f vert(appdata_base v)
30.             {
31.                 v2f o;
32.                 o.pos = UnityObjectToClipPos(v.vertex);
33.                 TRANSFER_VERTEX_TO_FRAGMENT(o);
34.                 return o;
35.             }
36.  
37.             fixed4 frag(v2f i) : COLOR
38.             {
39.                 float attenuation = LIGHT_ATTENUATION(i);
40.                 return fixed4(0,0,0,(1 - attenuation)*_ShadowIntensity) * _Color;
41.             }
42.            
43.             ENDCG
44.         }
45.     }
46.    
47.     Fallback "VertexLit"
48. }