Hi, I need help with "shader mask" for SkeletonAnimation in Unity bescause I don't know anything about shader 🙁

I have 2 types of plants in my project.
Type 1: is a static object, using the sprite renderer + sprite mask component to show the "white shadow" of the character when standing behind the tree.
Type 2: It is an animated tree, it uses SkeletonAnimation with a Skeleton Mask shader that I edited from Skeleton tint black so it has the same effect as type 1.
To edit the skeleton mask shader, I referred to this link:

esotericsoftware.com/forum/d/16082-animated-maskunity-help/7

and added this line of code as advised:

float4 frag (VertexOutput i) : SV_Target {
    float4 texColor = tex2D(_MainTex, i.uv);
    clip((texColor.a * i.vertexColor.a) - _Cutoff); // add this line

#if defined(_STRAIGHT_ALPHA_INPUT)
texColor.rgb *= texColor.a;
#endif

return (texColor * i.vertexColor);
}

But it seems ineffective. It still has the same problem as in the link I just mentioned, you can see 2 pictures illustrating my 2 types of plants

Tree (SkeletonAnimation) with shader Spine/Skeleton Mask. It is masked throughout the entire image area, even when the pixels are transparent.

Tree (Sprite Renderer) with Sprite Mask. It works fine.

Here is the shader code:

`Shader "Spine/Skeleton Mask" {
Properties{
_Color("Tint Color", Color) = (1,1,1,1)
_Black("Dark Color", Color) = (0,0,0,0)
[NoScaleOffset] MainTex("MainTex", 2D) = "black" {}
[Toggle(STRAIGHT_ALPHA_INPUT)] _StraightAlphaInput("Straight Alpha Texture", Int) = 0
Cutoff("Alpha Cutoff", Range(0.0, 1.0)) = 0.5
[Toggle(DARK_COLOR_ALPHA_ADDITIVE)] _DarkColorAlphaAdditive("Additive DarkColor.A", Int) = 0
[HideInInspector] _StencilRef("Stencil Reference", Float) = 1.0
[HideInInspector][Enum(UnityEngine.Rendering.CompareFunction)] _StencilComp("Stencil Comparison", Float) = 8 // Set to Always as default
}

    SubShader{
        Tags { "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" }
        LOD 100

        Fog { Mode Off }
        Cull Off
        ZWrite Off
        Blend One OneMinusSrcAlpha
        Lighting Off

        Stencil {
            Ref[_StencilRef]
            Comp[_StencilComp]
            Pass Replace
        }

        Pass {
            Name "Normal"

            CGPROGRAM
            #pragma shader_feature _ _STRAIGHT_ALPHA_INPUT
            #pragma shader_feature _ _DARK_COLOR_ALPHA_ADDITIVE
            #define _ALPHA_CLIP                     
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
            sampler2D _MainTex;
            float4 _Color;
            float4 _Black;
            float2 _Cutoff;

            struct VertexInput {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
                float4 vertexColor : COLOR;
                float2 uv1 : TEXCOORD1;
                float2 uv2 : TEXCOORD2;
            };

            struct VertexOutput {
                float4 pos : SV_POSITION;
                float2 uv : TEXCOORD0;
                float4 vertexColor : COLOR;
                float3 darkColor : TEXCOORD1;
            };

            VertexOutput vert(VertexInput v) {
                VertexOutput o;
                o.pos = UnityObjectToClipPos(v.vertex);
                o.uv = v.uv;
                o.vertexColor = v.vertexColor * float4(_Color.rgb * _Color.a, _Color.a);
                o.darkColor = float3(v.uv1.r, v.uv1.g, v.uv2.r);
                return o;
            }
            #include "CGIncludes/Spine-Skeleton-Tint-Common.cginc"
            float4 frag(VertexOutput i) : SV_Target
            {
                float4 texColor = tex2D(_MainTex, i.uv);
                #if defined(_STRAIGHT_ALPHA_INPUT)
                texColor.rgb *= texColor.a;
                #endif
                clip((texColor.a* i.vertexColor.a) - _Cutoff);
                return fragTintedColor(texColor, _Black.rgb + i.darkColor, i.vertexColor, _Color.a, _Black.a);
            }
            ENDCG
        }

        Pass {
            Name "Caster"
            Tags { "LightMode" = "ShadowCaster" }
            Offset 1, 1
            ZWrite On
            ZTest LEqual

            Fog { Mode Off }
            Cull Off
            Lighting Off

            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma multi_compile_shadowcaster
            #pragma fragmentoption ARB_precision_hint_fastest
            #include "UnityCG.cginc"
            sampler2D _MainTex;
            fixed _Cutoff;

            struct VertexOutput {
                V2F_SHADOW_CASTER;
                float4 uvAndAlpha : TEXCOORD1;
            };

            VertexOutput vert(appdata_base v, float4 vertexColor : COLOR) {
                VertexOutput o;
                o.uvAndAlpha = v.texcoord;
                o.uvAndAlpha.a = vertexColor.a;
                TRANSFER_SHADOW_CASTER(o)
                return o;
            }

            float4 frag(VertexOutput i) : SV_Target {
                fixed4 texcol = tex2D(_MainTex, i.uvAndAlpha.xy);
                clip(texcol.a* i.uvAndAlpha.a - _Cutoff);
                SHADOW_CASTER_FRAGMENT(i)
            }
            ENDCG
        }
}
    CustomEditor "SpineShaderWithOutlineGUI"