117 lines
4.4 KiB
Markdown
117 lines
4.4 KiB
Markdown
---
|
||
title: GBuffer&Material&BasePass
|
||
date: 2023-12-08 17:34:58
|
||
excerpt:
|
||
tags:
|
||
rating: ⭐
|
||
---
|
||
|
||
# # GBuffer
|
||
UE5 GBuffer内容：
|
||
[[UE GBuffer存储数据]]
|
||
```c#
|
||
OutGBufferA = WorldNormal/PerObjectGBufferData
|
||
OutGBufferB = Metallic/Specular/Roughness/EncodeShadingModelIdAndSelectiveOutputMask(GBuffer.ShadingModelID, GBuffer.SelectiveOutputMask);
|
||
OutGBufferC = BaseColor/GBufferAO
|
||
OutGBufferD = GBuffer.CustomData;
|
||
OutGBufferE = GBuffer.PrecomputedShadowFactors;
|
||
|
||
// 0..1, 2 bits, use CastContactShadow(GBuffer) or HasDynamicIndirectShadowCasterRepresentation(GBuffer) to extract
|
||
half PerObjectGBufferData;
|
||
```
|
||
|
||
ToonGBuffer修改&数据存储：
|
||
```c#
|
||
OutGBufferA:PerObjectGBufferData => 可以存储额外的有关Tonn渲染功能参数。
|
||
OutGBufferB:Metallic/Specular/Roughness =>
|
||
? / SpcularMask(控制高光形状与Mask) / ? / ?
|
||
//ToonHairMask OffsetShadowMask/SpcularMask/SpecularValue
|
||
OutGBufferD:CustomData.xyzw =>
|
||
ShaderColor.rgb / NoLOffset //ShadowColor这里可以在Material里通过主光向量、ShadowStep、Shadow羽化计算多层阴影效果。
|
||
OutGBufferE:GBuffer.PrecomputedShadowFactors.xyzw =>
|
||
ToonDataID/ ToonObjectID(判断是否是一个物体) /OutlineMask 控制Outline绘制以及Outline强度 / ToonAO
|
||
OutGBufferF:velocity =>
|
||
? / ? / ? / ?
|
||
```
|
||
|
||
蓝色协议的方案
|
||
![[蓝色协议的方案#GBuffer]]
|
||
|
||
## Toon PerObjectGBufferData具体功能表
|
||
从3开始，0、1、2已被占用。
|
||
- ?
|
||
|
||
## ToonData
|
||
|
||
|
||
## 高光
|
||
- PBR高光（使用Roughness控制是否可行？是否需要传入GBuffer一个Mask贴图）
|
||
- 自定义高光：高光贴图、高光颜色、参数化高光形状、多层高光
|
||
|
||
# 顶点色
|
||
## 蓝色协议
|
||
用于存储一些低精度数据，插值即可
|
||
- 顶点色：
|
||
- R:阴影区域控制（强度） 0~1
|
||
- G:描边宽度
|
||
- B:ToonAO
|
||
- 第二套顶点色（UV Channel1）：
|
||
- R:深度偏移
|
||
- G:用来区分内轮廓不同部位的ID
|
||
|
||
蓝色协议的R:阴影区域标记 与 B:AO，而罪恶装备使用贴图来传递信息。
|
||
## 罪恶装备
|
||
对阴影判断阈值的偏移。（见前面着色部分，顶点AO+手绘修正）
|
||
R:阴影偏移
|
||
G:轮廓线根据与相机的距离扩大多少的系数
|
||
B:等高线 Z 轴偏移值
|
||
|
||
# 罪恶装备
|
||
8,G为阴影控（AO），R为高光强度参数，金属和光滑材质的部分设置的更大一些。B通道：用于照明控制。最大值为高光，反之，值越小高光越淡。
|
||
|
||
|
||
https://zhuanlan.zhihu.com/p/360229590一文中介绍了崩坏3与原神的计算方式
|
||
|
||
崩坏3的LightMap计算方式：
|
||
```c++
|
||
half4 baseColor = SAMPLE_TEXTURE2D(_BaseMap, sampler_BaseMap, input.uv.xy);
|
||
half4 LightMapColor = SAMPLE_TEXTURE2D(_LightMap, sampler_LightMap, input.uv.xy);
|
||
half3 ShadowColor = baseColor.rgb * _ShadowMultColor.rgb;
|
||
half3 DarkShadowColor = baseColor.rgb * _DarkShadowMultColor.rgb;
|
||
|
||
//如果SFactor = 0,ShallowShadowColor为一级阴影色,否则为BaseColor。
|
||
float SWeight = (LightMapColor.g * input.color.r + input.lambert) * 0.5 + 1.125;
|
||
float SFactor = floor(SWeight - _ShadowArea);
|
||
half3 ShallowShadowColor = SFactor * baseColor.rgb + (1 - SFactor) * ShadowColor.rgb;
|
||
```
|
||
|
||
二级阴影计算:
|
||
```c++
|
||
//如果SFactor = 0,DarkShadowColor为二级阴影色,否则为一级阴影色。
|
||
SFactor = floor(SWeight - _DarkShadowArea);
|
||
DarkShadowColor = SFactor * (_FixDarkShadow * ShadowColor + (1 - _FixDarkShadow) * ShallowShadowColor) + (1 - SFactor) * DarkShadowColor;
|
||
|
||
// 平滑阴影边缘
|
||
half rampS = smoothstep(0, _ShadowSmooth, input.lambert - _ShadowArea);
|
||
half rampDS = smoothstep(0, _DarkShadowSmooth, input.lambert - _DarkShadowArea);
|
||
ShallowShadowColor.rgb = lerp(ShadowColor, baseColor.rgb, rampS);
|
||
DarkShadowColor.rgb = lerp(DarkShadowColor.rgb, ShadowColor, rampDS);
|
||
|
||
//如果SFactor = 0,FinalColor为二级阴影，否则为一级阴影。
|
||
SFactor = floor(LightMapColor.g * input.color.r + 0.9f);
|
||
half4 FinalColor;
|
||
FinalColor.rgb = SFactor * ShallowShadowColor + (1 - SFactor) * DarkShadowColor;
|
||
```
|
||
|
||
|
||
**罪恶装备**：
|
||
对阴影判断阈值的偏移。（见前面着色部分，顶点AO+手绘修正）
|
||
G : 轮廓线根据与相机的距离扩大多少的系数
|
||
B : 等高线 Z 轴偏移值
|
||
A : 轮廓厚度系数。0.5为标准，1为最大厚度，0为无等高线
|
||
|
||
# 蓝色协议
|
||
[[蓝色协议的方案]]
|
||
|
||
# 米哈游
|