如果代码中有什么不清楚请查看以下基础知识
Shader基础知识
unity3d 中 七种坐标知识详解
穿透描边着色器
就是物体被遮挡后,轮廓会显示出来。一般用于解决游戏中因视角问题重要目标被遮挡的问题,例如人物和宝箱。
大致就是这么个效果:
代码
Shader "Custom/Catoon" {
Properties{
_MainTex("Base (RGB)", 2D) = "white" {}
_OutlineColor("Outline Color", Color) = (1,1,0,1) //描边颜色
_Outline("Outline width", Range(0.0, 0.5)) = 0.03 // 描边宽度
}
CGINCLUDE
#include "UnityCG.cginc"
//获取顶点、法线、纹理坐标
struct appdata_t {
float4 vertex : POSITION;
float2 texcoord : TEXCOORD0;
float3 normal : NORMAL;
};
//
struct v2f {
float4 vertex : SV_POSITION;
half2 texcoord : TEXCOORD0;
};
sampler2D _MainTex;
float4 _MainTex_ST;
float _Outline;
float4 _OutlineColor;
v2f vert(appdata_t v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.texcoord = TRANSFORM_TEX(v.texcoord, _MainTex);
return o;
}
v2f vert_outline(appdata_t v)
{
v2f o;
// 方式一,观察空间 下往法线偏移顶点
float4 viewPos = mul(UNITY_MATRIX_MV, v.vertex);
//float3 viewNorm = mul((float3x3)UNITY_MATRIX_IT_MV, v.normal);
float3 viewNorm = mul(v.normal, (float3x3)UNITY_MATRIX_T_MV);
float3 offset = normalize(viewNorm) * _Outline;
viewPos.xyz += offset;
o.vertex = mul(UNITY_MATRIX_P, viewPos);
//方式二,世界空间 下往法线偏移顶点
//float4 worldPos = mul(unity_ObjectToWorld, v.vertex);
//float3 worldNormal = UnityObjectToWorldNormal(v.normal);
//float3 offset = normalize(worldNormal) * _Outline;
//worldPos.xyz += offset;
//o.vertex = mul(UNITY_MATRIX_VP, worldPos);
return o;
}
ENDCG
SubShader{
Tags{ "Queue" = "Transparent" "RenderType" = "Opaque" }
Pass{ // 正常绘制
Stencil
{
Ref 1
Comp Always
Pass Replace
ZFail Replace
}
ZTest LEqual
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
fixed4 frag(v2f i) : SV_Target
{
fixed4 col = tex2D(_MainTex, i.texcoord);
return col;
}
ENDCG
}
Pass{ // 遮挡部分绘制描边
ZTest Greater
ZWrite Off
//Blend DstAlpha OneMinusDstAlpha
Stencil{
Ref 1
Comp NotEqual
}
CGPROGRAM
#pragma vertex vert_outline
#pragma fragment frag
half4 frag(v2f i) :COLOR
{
return _OutlineColor;
}
ENDCG
}
}
}