Alpha Clip Shadow Problem

Unity Engine
, , ,
1

Hi! I have a question about the Shadow problem in Shader.

As I show the screenshot, I made simple dissolve shader.
However, you can see that the shadow maintains the shape of the mesh.
There must be needed some simple codes that changes shadow, but I have no idea for that.
I tried find with this issue, but no solution found.

I would appreciate it if you could help me resolve this issue.

unity_shader_clip_shadow
unity_shader_clip_shadow766×487 60.6 KB

And here are my shader codes :

Shader "Custom/URPCustomDissolve"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _NoiseMap ("NoiseMap", 2D) = "white" {}
        _DissolveAmount ("DissolveAmount", Range(0,1)) = 0.5
    }
    SubShader
    {
        Tags{ "RenderType"="Opaque" "RenderPipeline"="UniversalPipeline"
             }
        LOD 100

        Pass
        {
            //
            Blend SrcAlpha OneMinusSrcAlpha
            //Cull Off
            //ZWrite Off

            HLSLPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            // make fog work
            //#pragma multi_compile_fog
            // Shadow 컴파일
            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS_CASCADE 
            #pragma multi_compile_fragment _ _SHADOWS_SOFT 

            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Lighting.hlsl"

            struct appdata
            {
                float4 vertexOS : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertexCS : SV_POSITION; // SV : System Value 
            };

            TEXTURE2D(_MainTex);
            SAMPLER(sampler_MainTex);
            TEXTURE2D(_NoiseMap);
            SAMPLER(sampler_NoiseMap);

            // SRP Batcher 호환
            CBUFFER_START(UnityPerMaterial)
            float4 _MainTex_ST;
            float4 _NoiseMap_ST;
            float _DissolveAmount;
            CBUFFER_END

            v2f vert (appdata v)
            {
                v2f o;
                o.vertexCS = TransformObjectToHClip(v.vertexOS.xyz);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
            }

            // 픽셀처리
            half4 frag (v2f i) : SV_Target
            {
                // sample the texture
                half4 col = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, TRANSFORM_TEX(i.uv, _MainTex));
                half cutOut = SAMPLE_TEXTURE2D(_NoiseMap, sampler_NoiseMap, TRANSFORM_TEX(i.uv, _NoiseMap)).r;
                clip(cutOut - _DissolveAmount);
                
                // apply fog
                //UNITY_APPLY_FOG(i.fogCoord, col);
                return col;
            }
            //ENDCG
            ENDHLSL
        }

        Pass
        {
            Name "ShadowCaster"
            Tags {"LightMode"="ShadowCaster"}

            ZWrite On
            ZTest LEqual
            ColorMask 0
            Cull Front

            HLSLPROGRAM
            #pragma vertex ShadowPassVertex
            #pragma fragment ShadowPassFragment

            #include "Packages/com.unity.render-pipelines.universal/Shaders/SimpleLitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/ShadowCasterPass.hlsl"

            ENDHLSL
        }
    }
}
2

I Solve it my self!
All I need is same thing on the Shadow!

Here are codes

Pass
        {
            Name "ShadowCaster"
            Tags {"LightMode"="ShadowCaster"}

            ZWrite On
            ZTest LEqual
            ColorMask 0
            Cull Front

            HLSLPROGRAM
            #pragma vertex ShadowPassVertex
            #pragma fragment ShadowPassFragment
            #pragma shader_feature_local _ALPHA_CUTOUT
            //#pragma multi_compile _ _MAIN_LIGHT_SHADOWS _MAIN_LIGHT_SHADOWS_CASCADE _MAIN_LIGHT_SHADOWS_SCREEN

            #include "Packages/com.unity.render-pipelines.universal/Shaders/SimpleLitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/ShadowCasterPass.hlsl"

            // Dissolve 처리용 텍스처와 변수 선언
            // Define Variables for Dissolve
            TEXTURE2D(_NoiseMap);
            SAMPLER(sampler_NoiseMap);

            CBUFFER_START(UnityPerMaterial)
            float4 _NoiseMap_ST;
            float _DissolveAmount;
            CBUFFER_END

            struct appdata
            {
                float4 vertexOS : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertexCS : SV_POSITION;
            };

            v2f ShadowPassVertex(appdata v)
            {
                v2f o;
                o.vertexCS = TransformObjectToHClip(v.vertexOS.xyz);
                o.uv = TRANSFORM_TEX(v.uv, _NoiseMap);
                return o;
            }

             // 그림자에 Dissolve 적용
             // Applying Dissolve on the Shadow
            float4 ShadowPassFragment(v2f i) : SV_Target
            {
                float cutOut = SAMPLE_TEXTURE2D(_NoiseMap, sampler_NoiseMap, i.uv).r;
                clip(cutOut - _DissolveAmount); // Dissolve 처리
                return 0;
            }

            ENDHLSL
        }

Hope to help someone who has same problem with me.