卡通渲染 描边 outline 部分shader

顶点着色器

float4 viewPos = mul(UNITY_MATRIX_V, mul(unity_ObjectToWorld, v.vertex));
viewPos = viewPos / viewPos.w;

// float3 N = UnityObjectToViewPos(v.normal);
float3 N = mul((float3x3)UNITY_MATRIX_IT_MV, v.normal);
N.z = 0.0099999998;
N = normalize(N);
// 这段话是为了使得描边在放大缩小时不会改变大小
float S = -viewPos.z / unity_CameraProjection[1].y;
S = pow((S / _Scale), 0.5);
float tmp12 = _Outline * _Scale * v.color.w * S;
viewPos.xyz = viewPos.xyz + normalize(viewPos.xyz) * _MaxOutLineZOffset * _Scale * (v.color.z - 0.5);  
viewPos.xy = viewPos.xy + N.xy * tmp12; 

o.vertex = mul(UNITY_MATRIX_P, viewPos);