ShaderLab偏移量不呈现一个多边形高于另一个多边形

Question

我有两个着色器，UnlitRGBA和TransparentNoOverlap。它们如下：

UnlitRGBA.shaderlab

// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)
// modified by rbjacob101

Shader "Particles/Standard Unlit (RGBA)"
{
    Properties
    {
        _MainTex("Albedo", 2D) = "white" {}
    _Color("Color", Color) = (1,1,1,1)

        _Cutoff("Alpha Cutoff", Range(0.0, 1.0)) = 0.5

        _BumpScale("Scale", Float) = 1.0
        _BumpMap("Normal Map", 2D) = "bump" {}

    _EmissionColor("Color", Color) = (0,0,0)
        _EmissionMap("Emission", 2D) = "white" {}

    _DistortionStrength("Strength", Float) = 1.0
        _DistortionBlend("Blend", Range(0.0, 1.0)) = 0.5

        _SoftParticlesNearFadeDistance("Soft Particles Near Fade", Float) = 0.0
        _SoftParticlesFarFadeDistance("Soft Particles Far Fade", Float) = 1.0
        _CameraNearFadeDistance("Camera Near Fade", Float) = 1.0
        _CameraFarFadeDistance("Camera Far Fade", Float) = 2.0

        // Hidden properties
        [HideInInspector] _Mode("__mode", Float) = 0.0
        [HideInInspector] _ColorMode("__colormode", Float) = 0.0
        [HideInInspector] _FlipbookMode("__flipbookmode", Float) = 0.0
        [HideInInspector] _LightingEnabled("__lightingenabled", Float) = 0.0
        [HideInInspector] _DistortionEnabled("__distortionenabled", Float) = 0.0
        [HideInInspector] _EmissionEnabled("__emissionenabled", Float) = 0.0
        [HideInInspector] _BlendOp("__blendop", Float) = 0.0
        [HideInInspector] _SrcBlend("__src", Float) = 1.0
        [HideInInspector] _DstBlend("__dst", Float) = 0.0
        [HideInInspector] _ZWrite("__zw", Float) = 1.0
        [HideInInspector] _Cull("__cull", Float) = 2.0
        [HideInInspector] _SoftParticlesEnabled("__softparticlesenabled", Float) = 0.0
        [HideInInspector] _CameraFadingEnabled("__camerafadingenabled", Float) = 0.0
        [HideInInspector] _SoftParticleFadeParams("__softparticlefadeparams", Vector) = (0,0,0,0)
        [HideInInspector] _CameraFadeParams("__camerafadeparams", Vector) = (0,0,0,0)
        [HideInInspector] _ColorAddSubDiff("__coloraddsubdiff", Vector) = (0,0,0,0)
        [HideInInspector] _DistortionStrengthScaled("__distortionstrengthscaled", Float) = 0.0
    }

        Category
    {
        SubShader
    {
        Tags{ "RenderType" = "Opaque" "IgnoreProjector" = "True" "PreviewType" = "Plane" "PerformanceChecks" = "False" }

        BlendOp[_BlendOp]
        Blend[_SrcBlend][_DstBlend]
        ZWrite[_ZWrite]
        Offset -1, -1
        Cull[_Cull]
        ColorMask RGBA

        GrabPass
    {
        Tags{ "LightMode" = "Always" }
        "_GrabTexture"
    }

        Pass
    {
        Name "ShadowCaster"
        Tags{ "LightMode" = "ShadowCaster" }

        BlendOp Add
        Blend One Zero
        ZWrite On
        Cull Off

        CGPROGRAM
#pragma target 2.5

#pragma shader_feature _ _ALPHATEST_ON _ALPHABLEND_ON _ALPHAPREMULTIPLY_ON _ALPHAMODULATE_ON
#pragma shader_feature _ _COLOROVERLAY_ON _COLORCOLOR_ON _COLORADDSUBDIFF_ON
#pragma shader_feature _REQUIRE_UV2
#pragma multi_compile_shadowcaster
#pragma multi_compile_instancing
#pragma instancing_options procedural:vertInstancingSetup

#pragma vertex vertParticleShadowCaster
#pragma fragment fragParticleShadowCaster

#include "UnityStandardParticleShadow.cginc"
        ENDCG
    }

        Pass
    {
        Tags{ "LightMode" = "ForwardBase" }

        CGPROGRAM
#pragma multi_compile __ SOFTPARTICLES_ON
#pragma multi_compile_fog
#pragma target 2.5

#pragma shader_feature _ _ALPHATEST_ON _ALPHABLEND_ON _ALPHAPREMULTIPLY_ON _ALPHAMODULATE_ON
#pragma shader_feature _ _COLOROVERLAY_ON _COLORCOLOR_ON _COLORADDSUBDIFF_ON
#pragma shader_feature _NORMALMAP
#pragma shader_feature _EMISSION
#pragma shader_feature _FADING_ON
#pragma shader_feature _REQUIRE_UV2
#pragma shader_feature EFFECT_BUMP

#pragma vertex vertParticleUnlit
#pragma fragment fragParticleUnlit
#pragma multi_compile_instancing
#pragma instancing_options procedural:vertInstancingSetup

#include "UnityStandardParticles.cginc"
        ENDCG
    }
    }
    }

        Fallback "VertexLit"
        CustomEditor "StandardParticlesShaderGUI"
}

TransparentNoOverlap.shader

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

/*
 * Taken from:
 * https://forum.unity.com/threads/transparent-depth-shader-good-for-ghosts.149511/
 */

Shader "Transparent/TransparentNoOverlap" {
Properties {
     [PerRendererData]_Color ("Main Color", Color) = (1,1,1,1)
    _MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}
}

SubShader {
    Tags {"RenderType"="Transparent" "Queue"="Transparent" "IgnoreProjector"="True"}
    LOD 200

    Pass {
        Name "TRANSPARENT"

        ZWrite On
        ZTest LEqual
        Blend SrcAlpha OneMinusSrcAlpha
        ColorMask RGBA

        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag
        #include "UnityCG.cginc"

        fixed4 _Color;

        struct v2f {
            float4 pos : SV_POSITION;
        };

        v2f vert (appdata_base v)
        {
            v2f o;
            o.pos = UnityObjectToClipPos (v.vertex);
            return o;
        }

        half4 frag (v2f i) : COLOR
        {
            return _Color;
        }
        ENDCG  
    }

    CGPROGRAM
    #pragma surface surf Lambert alpha
    #pragma debug

    sampler2D _MainTex;
    fixed4 _Color;

    struct Input {
        float2 uv_MainTex;
    };

    void surf (Input IN, inout SurfaceOutput o) {
        fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
        o.Albedo = c.rgba;
        o.Alpha = c.a;
    }
    ENDCG
}

Fallback "Transparent/Diffuse"
}

我希望使用UnlitRGBA的材料总是在TransparentNoOverlap上呈现。我会怎样做才能取得这个结果呢？我尝试过将Offset -1, -1或Offset 0, -1添加到UnlitRGBA中。当对标准表面着色器进行测试时，它工作得很好，并且UnlitRGBA始终在上面呈现。但是在用TransparentNoOverlap进行渲染时，要么是z格斗，要么是TransparentNoOverlap总是在上面呈现。为什么会这样呢？我认为这可能与ZTests或ZWrites有关，但我最终还是不确定。

我为大量的代码样本道歉..。谢谢你能提供的任何帮助。

罗杰克布

Answer 1

请注意，预期的结果和设置略显模糊，因此可能有几种方法可供选择。

简单地说：材质有着色器A(未亮)被B覆盖(透明)，因为B是在它之后画。“队列”=“透明”是B. Shader A中负责此效果的标志，因此它使用默认的“几何”队列。(您可以在这里阅读到在“遮罩”下使用的索引值：https://docs.unity3d.com/Manual/SL-SubShaderTags.html)。因此，在这方面，您可以显式地指定队列索引，并确保它们与预期的行为相匹配。

这忽略了另一个方面: ZBuffer处理一个网格被另一个网格遮挡，因此它们实际上不依赖于该绘制顺序。可以根据深度测试丢弃像素，如果指定这样做，则对象可以写入深度。(https://docs.unity3d.com/Manual/SL-CullAndDepth.html)

网格显示z格斗，如果它们都是写和测试的，并且是共面的(在同一个位置)，或者缓冲区的精度很低，所以存储的值使它们看起来像是。

如果你的网格需要被遮挡和封闭他人和自己，一种方法是设置B(透明的)来使用ZTest Less，这样只有当A根本不存在时，即使是在A之后绘制，即使它与A共面，也只会出现。