Shadows

Hi,
I'm trying to force my shader to cast shadows, but he is very stubborn
Please let me know what I do wrong.
In frag I multiply finalColor *= tex2D(_ShadowMapTexture, i.shadow).a;
and this is my shadow caster pass :

Code (CSharp):

1. Pass{
2.             Name "ShadowCaster"
3.             Tags {"Queue" = "Opaque" "LightMode" = "ShadowCaster"}
4.             ZWrite On
5.             Cull Off
6.  
7.             CGPROGRAM
8.             #pragma vertex vert
9.             #pragma fragment frag
10.  
11.             struct input {
12.                 float4 pos : POSITION;
13.             };
14.  
15.             struct output {
16.                 float4 pos : SV_POSITION;
17.             };
18.  
19.             output vert(input v) {
20.                 output o;
21.                 o.pos = UnityObjectToClipPos(v.pos);
22.                 return o;
23.             }
24.  
25.             float4 frag(output i) : SV_Target{
26.                 return 0;
27.             }
28.  
29.             ENDCG
30.         }

 

https://docs.unity3d.com/Manual/SL-VertexFragmentShaderExamples.html check out this documentation page, it has a pretty detailed explanation of how to apply built-in shadowcasting and shadowreceiving to your custom shaders

 

EDIT: thought this was a bot as other bots have similar names, but their posting actually seems potentially real :/ confusing!

 

In the article I see some functions probably from UnityCG.cginc, but I want to understand it deeply and do it more manually. I want to use global sampler2D variable for shadows or something like this.

 

If you want to understand it more deeply, just go check out the contents of UnityCG.cginc and see what those macros unroll to. UnityCG can be downloaded from Unity download archive -> built-in shaders. https://unity3d.com/get-unity/download/archive

You can also always check the final GLSL or HLSL shader if you're comfortable with that.

 

Could you explain me what unity_WorldToShadow[] array contains? I googled it but with poor result

 

Most likely it's the transform matrix to that's used to convert world space coordinates to a "shadow space" coordinates. Much like you would do when rendering from a light's point of view. But it should be of different position than the light itself so it covers the whole screen of objects.