模板缓冲一般用于遮罩渲染的功能，其原理很以前聊过（模板缓冲原理），就不再啰嗦了。
现在实现一个功能：使用一个长方体（或任意物体）遮罩渲染对象（比如一个球）。
首先在官网下载内置着色器，找到DefaultResourcesExtra中的Standard.shader，改造一下支持stencil操作，如下：
Shader "Standard-Stencil"
{
Properties
{
_StencilVal("Stencil Value", int) = 1
_StencilComp("Stencil CompFunction (Disable,0,Never,1,Less,2,Equal,3,LessEqual,4,Greater,5,NotEqual,6,GreaterEqual,7,Always,8)", int) = 3
_StencilPass("StencilPassFunciton(Keep,0,Zero,1,Replace,2,IncrSat,3,DecrSat,4,Invert,5,IncrWrap,6,DecrWrap,7)", int) = 0
[Enum(Less,0,Greater,1,LEqual,2,GEqual,3,Equal,4,NotEqual,5,Always,6)]_ZTest("ZTest",int) = 0
[Enum(Off,0,Front,1,Back,2)]_Cull("Cull", int) = 2
_Color("Color", Color) = (1,1,1,1)
_MainTex("Albedo", 2D) = "white" {}
_Cutoff("Alpha Cutoff", Range(0.0, 1.0)) = 0.5
_Glossiness("Smoothness", Range(0.0, 1.0)) = 0.5
_GlossMapScale("Smoothness Scale", Range(0.0, 1.0)) = 1.0
[Enum(Metallic Alpha,0,Albedo Alpha,1)] _SmoothnessTextureChannel ("Smoothness texture channel", Float) = 0
[Gamma] _Metallic("Metallic", Range(0.0, 1.0)) = 0.0
_MetallicGlossMap("Metallic", 2D) = "white" {}
[ToggleOff] _SpecularHighlights("Specular Highlights", Float) = 1.0
[ToggleOff] _GlossyReflections("Glossy Reflections", Float) = 1.0
_BumpScale("Scale", Float) = 1.0
_BumpMap("Normal Map", 2D) = "bump" {}
_Parallax ("Height Scale", Range (0.005, 0.08)) = 0.02
_ParallaxMap ("Height Map", 2D) = "black" {}
_OcclusionStrength("Strength", Range(0.0, 1.0)) = 1.0
_OcclusionMap("Occlusion", 2D) = "white" {}
_EmissionColor("Color", Color) = (0,0,0)
_EmissionMap("Emission", 2D) = "white" {}
_DetailMask("Detail Mask", 2D) = "white" {}
_DetailAlbedoMap("Detail Albedo x2", 2D) = "grey" {}
_DetailNormalMapScale("Scale", Float) = 1.0
_DetailNormalMap("Normal Map", 2D) = "bump" {}
[Enum(UV0,0,UV1,1)] _UVSec ("UV Set for secondary textures", Float) = 0
// Blending state
[HideInInspector] _Mode ("__mode", Float) = 0.0
[HideInInspector] _SrcBlend ("__src", Float) = 1.0
[HideInInspector] _DstBlend ("__dst", Float) = 0.0
[HideInInspector] _ZWrite ("__zw", Float) = 1.0
}
CGINCLUDE
#define UNITY_SETUP_BRDF_INPUT MetallicSetup
ENDCG
SubShader
{
Tags { "RenderType"="Opaque" "PerformanceChecks"="False" }
LOD 300
// ------------------------------------------------------------------
// Base forward pass (directional light, emission, lightmaps, ...)
Pass
{
Name "FORWARD"
Tags { "LightMode" = "ForwardBase" }
Blend [_SrcBlend] [_DstBlend]
ZWrite [_ZWrite]
ZWrite [_ZTest]
Stencil
{
Ref [_StencilVal]
Comp [_StencilComp]
Pass [_StencilPass]
}
Cull [_Cull]
CGPROGRAM
#pragma target 3.0
// -------------------------------------
#pragma shader_feature _NORMALMAP
#pragma shader_feature _ _ALPHATEST_ON _ALPHABLEND_ON _ALPHAPREMULTIPLY_ON
#pragma shader_feature _EMISSION
#pragma shader_feature _METALLICGLOSSMAP
#pragma shader_feature ___ _DETAIL_MULX2
#pragma shader_feature _ _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
#pragma shader_feature _ _SPECULARHIGHLIGHTS_OFF
#pragma shader_feature _ _GLOSSYREFLECTIONS_OFF
#pragma shader_feature _PARALLAXMAP
#pragma multi_compile_fwdbase
#pragma multi_compile_fog
#pragma multi_compile_instancing
// Uncomment the following line to enable dithering LOD crossfade. Note: there are more in the file to uncomment for other passes.
//#pragma multi_compile _ LOD_FADE_CROSSFADE
#pragma vertex vertBase
#pragma fragment fragBase
#include "UnityStandardCoreForward.cginc"
ENDCG
}
// ------------------------------------------------------------------
// Additive forward pass (one light per pass)
Pass
{
Name "FORWARD_DELTA"
Tags { "LightMode" = "ForwardAdd" }
Blend [_SrcBlend] One
Fog { Color (0,0,0,0) } // in additive pass fog should be black
ZWrite Off
ZTest LEqual
CGPROGRAM
#pragma target 3.0
// -------------------------------------
#pragma shader_feature _NORMALMAP
#pragma shader_feature _ _ALPHATEST_ON _ALPHABLEND_ON _ALPHAPREMULTIPLY_ON
#pragma shader_feature _METALLICGLOSSMAP
#pragma shader_feature _ _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
#pragma shader_feature _ _SPECULARHIGHLIGHTS_OFF
#pragma shader_feature ___ _DETAIL_MULX2
#pragma shader_feature _PARALLAXMAP
#pragma multi_compile_fwdadd_fullshadows
#pragma multi_compile_fog
// Uncomment the following line to enable dithering LOD crossfade. Note: there are more in the file to uncomment for other passes.
//#pragma multi_compile _ LOD_FADE_CROSSFADE
#pragma vertex vertAdd
#pragma fragment fragAdd
#include "UnityStandardCoreForward.cginc"
ENDCG
}
// ------------------------------------------------------------------
// Shadow rendering pass
Pass {
Name "ShadowCaster"
Tags { "LightMode" = "ShadowCaster" }
ZWrite On ZTest LEqual
CGPROGRAM
#pragma target 3.0
// -------------------------------------
#pragma shader_feature _ _ALPHATEST_ON _ALPHABLEND_ON _ALPHAPREMULTIPLY_ON
#pragma shader_feature _METALLICGLOSSMAP
#pragma shader_feature _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
#pragma shader_feature _PARALLAXMAP
#pragma multi_compile_shadowcaster
#pragma multi_compile_instancing
// Uncomment the following line to enable dithering LOD crossfade. Note: there are more in the file to uncomment for other passes.
//#pragma multi_compile _ LOD_FADE_CROSSFADE
#pragma vertex vertShadowCaster
#pragma fragment fragShadowCaster
#include "UnityStandardShadow.cginc"
ENDCG
}
// ------------------------------------------------------------------
// Deferred pass
Pass
{
Name "DEFERRED"
Tags { "LightMode" = "Deferred" }
CGPROGRAM
#pragma target 3.0
#pragma exclude_renderers nomrt
// -------------------------------------
#pragma shader_feature _NORMALMAP
#pragma shader_feature _ _ALPHATEST_ON _ALPHABLEND_ON _ALPHAPREMULTIPLY_ON
#pragma shader_feature _EMISSION
#pragma shader_feature _METALLICGLOSSMAP
#pragma shader_feature _ _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
#pragma shader_feature _ _SPECULARHIGHLIGHTS_OFF
#pragma shader_feature ___ _DETAIL_MULX2
#pragma shader_feature _PARALLAXMAP
#pragma multi_compile_prepassfinal
#pragma multi_compile_instancing
// Uncomment the following line to enable dithering LOD crossfade. Note: there are more in the file to uncomment for other passes.
//#pragma multi_compile _ LOD_FADE_CROSSFADE
#pragma vertex vertDeferred
#pragma fragment fragDeferred
#include "UnityStandardCore.cginc"
ENDCG
}
// ------------------------------------------------------------------
// Extracts information for lightmapping, GI (emission, albedo, ...)
// This pass it not used during regular rendering.
Pass
{
Name "META"
Tags { "LightMode"="Meta" }
Cull Off
CGPROGRAM
#pragma vertex vert_meta
#pragma fragment frag_meta
#pragma shader_feature _EMISSION
#pragma shader_feature _METALLICGLOSSMAP
#pragma shader_feature _ _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
#pragma shader_feature ___ _DETAIL_MULX2
#pragma shader_feature EDITOR_VISUALIZATION
#include "UnityStandardMeta.cginc"
ENDCG
}
}
SubShader
{
Tags { "RenderType"="Opaque" "PerformanceChecks"="False" }
LOD 150
// ------------------------------------------------------------------
// Base forward pass (directional light, emission, lightmaps, ...)
Pass
{
Name "FORWARD"
Tags { "LightMode" = "ForwardBase" }
Blend [_SrcBlend] [_DstBlend]
ZWrite [_ZWrite]
CGPROGRAM
#pragma target 2.0
#pragma shader_feature _NORMALMAP
#pragma shader_feature _ _ALPHATEST_ON _ALPHABLEND_ON _ALPHAPREMULTIPLY_ON
#pragma shader_feature _EMISSION
#pragma shader_feature _METALLICGLOSSMAP
#pragma shader_feature _ _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
#pragma shader_feature _ _SPECULARHIGHLIGHTS_OFF
#pragma shader_feature _ _GLOSSYREFLECTIONS_OFF
// SM2.0: NOT SUPPORTED shader_feature ___ _DETAIL_MULX2
// SM2.0: NOT SUPPORTED shader_feature _PARALLAXMAP
#pragma skip_variants SHADOWS_SOFT DIRLIGHTMAP_COMBINED
#pragma multi_compile_fwdbase
#pragma multi_compile_fog
#pragma vertex vertBase
#pragma fragment fragBase
#include "UnityStandardCoreForward.cginc"
ENDCG
}
// ------------------------------------------------------------------
// Additive forward pass (one light per pass)
Pass
{
Name "FORWARD_DELTA"
Tags { "LightMode" = "ForwardAdd" }
Blend [_SrcBlend] One
Fog { Color (0,0,0,0) } // in additive pass fog should be black
ZWrite Off
ZTest LEqual
CGPROGRAM
#pragma target 2.0
#pragma shader_feature _NORMALMAP
#pragma shader_feature _ _ALPHATEST_ON _ALPHABLEND_ON _ALPHAPREMULTIPLY_ON
#pragma shader_feature _METALLICGLOSSMAP
#pragma shader_feature _ _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
#pragma shader_feature _ _SPECULARHIGHLIGHTS_OFF
#pragma shader_feature ___ _DETAIL_MULX2
// SM2.0: NOT SUPPORTED shader_feature _PARALLAXMAP
#pragma skip_variants SHADOWS_SOFT
#pragma multi_compile_fwdadd_fullshadows
#pragma multi_compile_fog
#pragma vertex vertAdd
#pragma fragment fragAdd
#include "UnityStandardCoreForward.cginc"
ENDCG
}
// ------------------------------------------------------------------
// Shadow rendering pass
Pass {
Name "ShadowCaster"
Tags { "LightMode" = "ShadowCaster" }
ZWrite On ZTest LEqual
CGPROGRAM
#pragma target 2.0
#pragma shader_feature _ _ALPHATEST_ON _ALPHABLEND_ON _ALPHAPREMULTIPLY_ON
#pragma shader_feature _METALLICGLOSSMAP
#pragma shader_feature _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
#pragma skip_variants SHADOWS_SOFT
#pragma multi_compile_shadowcaster
#pragma vertex vertShadowCaster
#pragma fragment fragShadowCaster
#include "UnityStandardShadow.cginc"
ENDCG
}
// ------------------------------------------------------------------
// Extracts information for lightmapping, GI (emission, albedo, ...)
// This pass it not used during regular rendering.
Pass
{
Name "META"
Tags { "LightMode"="Meta" }
Cull Off
CGPROGRAM
#pragma vertex vert_meta
#pragma fragment frag_meta
#pragma shader_feature _EMISSION
#pragma shader_feature _METALLICGLOSSMAP
#pragma shader_feature _ _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
#pragma shader_feature ___ _DETAIL_MULX2
#pragma shader_feature EDITOR_VISUALIZATION
#include "UnityStandardMeta.cginc"
ENDCG
}
}
FallBack "VertexLit"
//CustomEditor "StandardShaderGUI"
}
PS:本来想把CompareFunction和PassFunction做成Enum标签，结果发现shader的Enum标签不支持超过7个，算是新发现。
一般情况standard材质够场景制作了，这个材质赋予球体。
接下来按照以前的做法写一个StencilMaskShader
Shader "StencilDemo/StencilMaskShader"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
}
SubShader
{
LOD 100
Pass
{
Tags { "RenderType"="Opaque" }
ColorMask 0
Stencil
{
Ref 1
Comp Always //(Disable,0,Never,1,Less,2,Equal,3,LessEqual,4,Greater,5,NotEqual,6,GreaterEqual,7,Always,8)
Pass Replace //(Keep,0,Zero,1,Replace,2,IncrSat,3,DecrSat,4,Invert,5,IncrWrap,6,DecrWrap,7)
}
ZWrite Off
ZTest Off
}
}
}
这个用于立方体，置换立方体蒙版区域的stencilvalue，用于显示球体。设置好球体的renderqueue>立方体的renderqueue。效果如下：
因为模板测试位于图形流水线片段处理阶段，所以看到的效果就如同球体投影到平面上遮罩显示一样，我们想要立体感的话可以用两种方案。
一.填充立方体剖面
Shader "StencilDemo/ZTestUnlitShader"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
}
SubShader
{
Tags { "RenderType"="Opaque+20" }
LOD 100
Pass
{
ZTest Greater
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};
sampler2D _MainTex;
float4 _MainTex_ST;
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
return o;
}
fixed4 frag (v2f i) : SV_Target
{
fixed4 col = tex2D(_MainTex, i.uv);
return col;
}
ENDCG
}
}
}
这里设置渲染立方体剖面材质的renderqueue>球体renderqueue，同时设定ZTest Greater，这样就能显示出立方体被球体遮挡的区域，就能形成填充剖面。效果如下：
这个技术和以前切水果游戏一样，无非切水果的剖面纹理使用了相应的水果内部纹理。
PS：当然用Texture3D来进行填充剖面，也是很好的想法。
第二种方法性能要求高一点，但是也有很多应用的地方，后面有时间再写。
![NSSCTF | [SWPUCTF 2021 新生赛]babyrce](https://img-blog.csdnimg.cn/direct/bb548376afc0491f8d1b40219c2672b3.png)
