法线外扩

Pass
    {
        Name"OutLine"
        Cull Front
        ZWrite On
        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag
        #include "UnityCG.cginc"

        struct appdata
        {
            float4 vertex : POSITION;
            float3 normal : NORMAL;
        };

        struct v2f
        {
            float4 PositionClip : SV_POSITION;
        };

        float _EdgeWidth;
        float4 _EdgeColor;


        v2f vert (appdata v)
        {
            v2f o;
            float3 PositionView= UnityObjectToViewPos(v.vertex);
            float3 NormalWS=UnityObjectToWorldNormal(v.normal);
            float3 NormalView =normalize(mul((float3x3)UNITY_MATRIX_V, NormalWS));//相机空间法线
            PositionView += NormalView * _EdgeWidth*0.001;
            o.PositionClip=mul(UNITY_MATRIX_P,float4(PositionView,1.0));
            return o;
        }

        half4 frag (v2f i) : SV_Target
        {

            return _EdgeColor;
        }
        ENDCG
    }

基于模版测试的法线外扩

//Base Pass中确认模版值
Stencil
{
    Ref 1
    Comp Always
    Pass Replace
}
//OutLine Pass
Pass
    {
        Stencil
        {
            Ref 1
            Comp NotEqual
        }

        CGPROGRAM

        #pragma vertex vert
        #pragma fragment frag

        float _EdgeWidth;
        fixed4 _EdgeColor;

        struct a2v 
        {
            float4 vertex : POSITION;
            float3 normal : NORMAL;
        }; 

        struct v2f 
        {
            float4 pos : SV_POSITION;
        };

        v2f vert (a2v v) 
        {
            v2f o;

            float4 pos = mul(UNITY_MATRIX_MV, v.vertex); 
            float3 normal = mul((float3x3)UNITY_MATRIX_IT_MV, v.normal);  
            normal.z = -0.5;
            pos = pos + float4(normalize(normal), 0) * _EdgeWidth*0.01;
            o.pos = mul(UNITY_MATRIX_P, pos);

            return o;
        }

        float4 frag(v2f i) : SV_Target 
        { 
                return float4(_EdgeColor.rgb, 1);               
        }
        ENDCG
    }