Question problem with my shader: no shadows through alphatest

hi all

see this pic:


Shadows do not appear between the 2 green lines....


Here's the shader code:

Code (CSharp):

1. Shader "My_shaders/MyStd"
2. {
3.     Properties {
4.         [NoScaleOffset] _MainTex ("Diffuse Texture", 2D) = "white" {}
5.       [NoScaleOffset] _DirtLMTex ("Dirt/AO-LM (RGB-A)", 2D) = "(RGBA: .98,.98,.98,1)" {} // bidouille: presque 1 pour eviter les effets de bord....
6.       _NightLightColor ("Lightmap color", Color) = (1,1,1,1)
7.         [NoScaleOffset] _BumpMap ("Normal Texture", 2D) = "bump" {}
8.  
9.     }
10.     SubShader {
11.         Pass{
12.             Tags { "LightMode" = "ForwardBase" }
13.             CGPROGRAM
14.  
15.          // my variants....
16.          #pragma multi_compile_local ___ WITH_CITY_NIGHTLIGHTS
17.  
18.             #pragma vertex vertex_program
19.             #pragma fragment fragment_program
20.  
21.          #pragma multi_compile_fog
22.  
23.          #pragma multi_compile_fwdbase nolightmap nodirlightmap nodynlightmap novertexlight
24.  
25.  
26.  
27.  
28.  
29.          #include "Lighting.cginc"
30.          #include "AutoLight.cginc"
31.          
32.             // My vars
33.             sampler2D _MainTex;
34.             sampler2D _BumpMap;
35.             sampler2D _DirtLMTex;
36.          static const half _BumpDistFade=20;
37.          static const half _BumpLengthFade=5;
38.      
39. #if defined(WITH_CITY_NIGHTLIGHTS)
40.          fixed4 _NightLightColor;
41. #endif
42.  
43.  
44.             // Base Input Structs
45.             struct APP2V {
46.                 float4 vertex: POSITION;
47.                 half3 normal: NORMAL;
48.                 half4 UV0: TEXCOORD0;
49.                 half4 UV1: TEXCOORD1;
50.                 half4 UVdissolve: TEXCOORD2;
51.                 half4 tangent: TANGENT;
52.             };
53.      
54.             struct V2F {
55.                 float4 pos: SV_POSITION;
56.                 half4 UV0: TEXCOORD0;
57.                 half4 UV1: TEXCOORD1;
58.                 half4 posWorld: TEXCOORD2;
59.                 half3 normalWorld: TEXCOORD3;
60.                 half3 tangentWorld: TEXCOORD4;
61.                 half3 binormalWorld: TEXCOORD5;
62.             SHADOW_COORDS(6) // shadows data into TEXCOORD6
63.             UNITY_FOG_COORDS(7) // fog in 7    
64.             };
65.  
66.  
67.          //========================================================================
68.          
69.             // Vertex program
70.             V2F vertex_program( APP2V v )
71.          {
72.                 V2F o;
73.              
74.                 o.normalWorld = normalize( mul( float4( v.normal, 0.0 ), unity_WorldToObject ).xyz );    
75.                 o.tangentWorld = normalize( mul( unity_ObjectToWorld, v.tangent ).xyz );
76.                 o.binormalWorld = normalize( cross( o.normalWorld, o.tangentWorld )* v.tangent.w);
77.                      
78.                 o.posWorld = mul( unity_ObjectToWorld, v.vertex );
79.                 o.pos = UnityObjectToClipPos( v.vertex );
80.                 o.UV0 = v.UV0;
81.                 o.UV1 = v.UV1;
82.  
83.             TRANSFER_SHADOW(o)
84.             UNITY_TRANSFER_FOG(o,o.pos);
85.              
86.                 return o;
87.             }
88.          
89.             // Fragment program
90.             float4 fragment_program( V2F i ): SV_Target
91.          {
92.             half3 pixel_in_cam = _WorldSpaceCameraPos.xyz - i.posWorld.xyz;
93.             half pixel_dist = length(pixel_in_cam);
94.  
95.                 half3 lightDirection = normalize( _WorldSpaceLightPos0.xyz );
96.  
97.                 // Texture Maps
98.             //--------------
99.             // diffuse
100.                 fixed4 diffuse = tex2D( _MainTex, i.UV0);
101.  
102.             // if diffuse texture have some alpha then clip under 0.5
103.             clip(diffuse.a-0.5);
104.  
105.      
106.             // dirt-AO
107.                 fixed4 dirt = tex2D( _DirtLMTex, i.UV1);// dirt and AO texture
108.          
109.             fixed3 diff = diffuse * dirt.rgb * 1.5; // *1.5 for less dark walls
110.  
111.             fixed3 normalDirection;
112.          
113.          
114.             // fading bumps with distance ( far walls do not need bumpmaps )
115.             //---------------------------------------------------------------
116.             if(pixel_dist < _BumpDistFade)
117.             {
118.                // bump
119.                fixed3 bump =  UnpackNormal (tex2D (_BumpMap,  i.UV0));
120.            
121.                // a revoir sur un vecteur plutot que sur des valeurs X et Y independantes
122.                fixed delta=saturate((pixel_dist-(_BumpDistFade-_BumpLengthFade))/_BumpLengthFade);
123.            
124.                // small interpolation to make bump coming less visible...
125.                bump = fixed3(lerp(bump.x,0,delta),lerp(bump.y,0,delta),1);
126.  
127.                // Normal Transpose Matrix ( i still do not get why this is here 8*(  )
128.                half3x3 local2WorldTranspose = half3x3(
129.                   i.tangentWorld,
130.                   i.binormalWorld,
131.                   i.normalWorld
132.                );
133.            
134.                // Calculate Normal Direction from normal and bumpies
135.                normalDirection = normalize( mul( bump, local2WorldTranspose ) );
136.             }
137.             else
138.             {
139.                normalDirection = i.normalWorld; // with no bumps
140.             }
141.            
142.            
143.             fixed3 outputColor;
144.            
145.            
146. #if defined(WITH_CITY_NIGHTLIGHTS)
147.             // Night lightmap and its color and its intensity
148.             fixed lm =  dirt.a;
149.             fixed3 emiss = lm * _NightLightColor.rgb;// * _NightLightFactor;
150.          
151.             // night city wall lightings with less dirt/AO....
152.             outputColor = diff * UNITY_LIGHTMODEL_AMBIENT.rgb + diffuse*(1-(dirt.rgb*lm-(lm-1)))*emiss*2;
153. #else
154.             // Lighting
155.             fixed3 diffuseReflection = _LightColor0.rgb * saturate( dot( normalDirection, lightDirection ) );
156.          
157.                 outputColor = diff * (diffuseReflection * SHADOW_ATTENUATION(i) + UNITY_LIGHTMODEL_AMBIENT.rgb);
158.              
159. #endif            
160.  
161.             UNITY_APPLY_FOG(i.fogCoord,outputColor);
162.          
163.                 return half4(outputColor, 1.0);
164.          
165.             // show grey normals+bumps
166. //                return half4(saturate( dot( normalDirection, lightDirection )),saturate( dot( normalDirection, lightDirection )),saturate( dot( normalDirection, lightDirection )), 1.0);
167.          
168.             }
169.          
170.             ENDCG
171.         }
172.    
173.       // shadow caster rendering pass, implemented manually
174.       // using macros from UnityCG.cginc
175.       Pass
176.       {
177.          Tags {"LightMode"="ShadowCaster"}
178.  
179.          CGPROGRAM
180.          #pragma vertex vert
181.          #pragma fragment frag
182.          #pragma multi_compile_shadowcaster
183.          #include "UnityCG.cginc"
184.  
185.          struct v2f {
186.              V2F_SHADOW_CASTER;
187.          };
188.  
189.          v2f vert(appdata_base v)
190.          {
191.              v2f o;
192.              TRANSFER_SHADOW_CASTER_NORMALOFFSET(o)
193.              return o;
194.          }
195.  
196.          float4 frag(v2f i) : SV_Target
197.          {
198.              SHADOW_CASTER_FRAGMENT(i)
199.          }
200.          ENDCG
201.       }
202.    }
203. }

I tried various things including deleting my shadow caster and calling for a tranp/cutout fallback, but nothing works....

Does anyone have an idea of what am doing wrong please ?

Note that i clip early in my shader code.....

Thanks and happy unitying !

 

Your shader caster pass also needs to sample the

_MainTex

and

clip()

.

The shadow caster pass is used both for shadow casting, and rendering the camera depth texture. The later of which Unity actually casts the directional shadows on to generate a screen space shadow texture. So if the shadow caster pass doesn't use alpha testing that matches the main forward pass directional shadows will appear to be casting on & from the un-clipped geometry.

 

Thanks @bgolus for your answer

This all makes sense but why it still did not work when i replace the shadow caster with an transparent/cutout/diffuse fallback ?

 

Cutout/Diffuse uses a

_Cutoff

property to set the

clip()

threshold. If your shader doesn't have that as a property it'll default to 0.0, which means no cutoff.

Add this line to your shader's properties.

[HideInInspector] _Cutoff ("Alpha cutoff", Range(0,1)) = 0.5[/code]