UnityPBR介绍及经验分享课件

UnityPBR介绍及经验分享UnityPBR介绍及经验分享1OutlinePBR使用背景知识介绍StandardShader代码分析使用经验及优化分享OutlinePBR使用背景知识介绍2Background讨论的实质上是PhysicallyBasedShading核心：材质在真实物理环境下的反应不考虑GI/AO/Light/Sun等Background讨论的实质上是PhysicallyBa3Background-Concepts漫反射(Diffusion)&反射(Reflection)金属(导电材料)&非金属(绝缘体)能量守恒材质不会比入射光更亮菲涅尔(Fresnel)Background-Concepts漫反射(Diffusi4Background常见误区用了PBR我们的画面就会变强PBR只能用于真实感游戏PBR非常消耗性能转PBR是很简单的一个事情技术只要提供一个Shader就行了第三方软件里的就是最终效果Background常见误区5Background-Advantages优势表达能力强，避免Shader爆炸+合并DC能量守恒，在不同条件下都正确项目内不同场景环境下复用，甚至项目间复用资源Background-Advantages优势6Background-Advantages优势IBL提供间接光照，最大限度模拟真实环境下光照条件让美术更容易制作金属感美术的职责划分感性=>理性只需要确保正确，不再需要对好看负责制作流程进一步拆分，建模/贴图/灯光职责清晰，风格统一Background-Advantages优势7Background-PBRvs.Non-PBRBackground-PBRvs.Non-PBR8Background-ReferencesBasicTheoryofPhysically-basedrenderingPhysicallyBasedShadinginUnitySIGGRAPH2010Course:Physically-BasedShadingModelsinFilmandGameProductionSébastienLagardePBR除了工作流，还有什么优势？HowtoMakePhotorealisticPBRMaterialsBackground-ReferencesBasicThe9StandardShaderhttps:///get-unity/download/archivebuiltin_shaders-5.5.0f3StandardShaderhttps://unity3d10StandardShader-FilesDefaultResourcesExtra/Standard.shaderCGIncludes/UnityStandardCore*.cgincForward管线StandardSimple为例禁用_PARALLAXMAP/DIRLIGHTMAP_COMBINED/DIRLIGHTMAP_SEPARATEStandardShader-FilesDefaultRe11StandardShadershader_feature切换功能ForwardBasePass平行光/自发光/lightmap/…ForwardAddPass额外光源一次一个StandardShadershader_feature切12StandardShaderStandardShaderGUI.cs根据UI切换参数StandardShaderStandardShaderG13StandardShader-Vert77-79初始化81-85世界空间/裁剪空间坐标88-92世界空间法线/视线94-100切空间109-112PBR预计算项Vert输出值将插值后传入Frag常见Shader优化技巧StandardShader-Vert77-79初始化14StandardShader-FragMainLightSimple获取主光源颜色/方向ndotl法向量和光源方向点积SHADOW_ATTENUATION接受阴影OcclusionOCC贴图FragmentGI全局光照UNITY_APPLY_FOG硬件雾StandardShader-FragMainLightS15StandardShader-UNITY_SETUP_BRDF_INPUTMetallic工作流输入：金属度+光滑度specColor=lerp(DielectricSpec,albedo,metallic)diffColor=albedo*lerp(1-DielectricSpec,0,metallic))Specular工作流输入：高光颜色+光滑度diffColor=albedo*(1-SpecularStrength(specColor))能量守恒金属specColor大，diffColor小非金属反之StandardShader-UNITY_SETUP_BR16StandardShader-FragmentGI250-261设置变量光照贴图或环境光263-274ReflectionProbeGPUGems3Chap.19IBLSphere无穷远Box本地校正UnityGlobalIlluminationGI核心函数StandardShader-FragmentGI250-17StandardShader-UnityGlobalGIUnityGI_BaseShadeSHPerPixel即LightProbeLightmap读取光照贴图颜色额外处理Directional实时光照贴图UnityGI_IndirectSpecularBox需要矫正反射方向根据粗糙度取mipmapStandardShader-UnityGlobalGIU18StandardShader-BRDFBRDF3_Indirect间接光的diff/spec处理BRDF3DirectSimple分为三档，套用不同BRDF近似，处理直接光照UNITY_BRDF_GI处理间接光directionallightmapsEmission自发光贴图StandardShader-BRDFBRDF3_Indi19StandardShaderStandardShader20Optimization-DCC&UnityOptimization-DCC&Unity21Optimization-HDRReflectionProbe高光去哪儿了？HDRProbevs.LDRProbeOptimization-HDRReflectionPr22Optimization-Gamma光的传输是线性一个场景里的两个光源效果是相加的RGB值大小代表光强(能量)Optimization-Gamma光的传输是线性23Optimization-GammasRGB值非线性shader默认的输入输出都是线性的GPUGems3:Chapter24.TheImportanceofBeingLinearOptimization-GammasRGB值非线性24Optimization-Variantsshader_feature/multi_compile打造最小版本ShaderOptimization-Variantsshader_fe25TODO-FALLBACKBRDF换回『经典模型』PBR塌陷成经典做法性能分级贴图合并：如Occlusion塌陷到Albedo选择性禁用IBL等TODO-FALLBACKBRDF换回『经典模型』26TODO-SpecularAAToksvigmap/2011/07/22/specular-showdown//TODO-SpecularAAToksvigmap27ProductProduct28UnityPBR介绍及经验分享UnityPBR介绍及经验分享29OutlinePBR使用背景知识介绍StandardShader代码分析使用经验及优化分享OutlinePBR使用背景知识介绍30Background讨论的实质上是PhysicallyBasedShading核心：材质在真实物理环境下的反应不考虑GI/AO/Light/Sun等Background讨论的实质上是PhysicallyBa31Background-Concepts漫反射(Diffusion)&反射(Reflection)金属(导电材料)&非金属(绝缘体)能量守恒材质不会比入射光更亮菲涅尔(Fresnel)Background-Concepts漫反射(Diffusi32Background常见误区用了PBR我们的画面就会变强PBR只能用于真实感游戏PBR非常消耗性能转PBR是很简单的一个事情技术只要提供一个Shader就行了第三方软件里的就是最终效果Background常见误区33Background-Advantages优势表达能力强，避免Shader爆炸+合并DC能量守恒，在不同条件下都正确项目内不同场景环境下复用，甚至项目间复用资源Background-Advantages优势34Background-Advantages优势IBL提供间接光照，最大限度模拟真实环境下光照条件让美术更容易制作金属感美术的职责划分感性=>理性只需要确保正确，不再需要对好看负责制作流程进一步拆分，建模/贴图/灯光职责清晰，风格统一Background-Advantages优势35Background-PBRvs.Non-PBRBackground-PBRvs.Non-PBR36Background-ReferencesBasicTheoryofPhysically-basedrenderingPhysicallyBasedShadinginUnitySIGGRAPH2010Course:Physically-BasedShadingModelsinFilmandGameProductionSébastienLagardePBR除了工作流，还有什么优势？HowtoMakePhotorealisticPBRMaterialsBackground-ReferencesBasicThe37StandardShaderhttps:///get-unity/download/archivebuiltin_shaders-5.5.0f3StandardShaderhttps://unity3d38StandardShader-FilesDefaultResourcesExtra/Standard.shaderCGIncludes/UnityStandardCore*.cgincForward管线StandardSimple为例禁用_PARALLAXMAP/DIRLIGHTMAP_COMBINED/DIRLIGHTMAP_SEPARATEStandardShader-FilesDefaultRe39StandardShadershader_feature切换功能ForwardBasePass平行光/自发光/lightmap/…ForwardAddPass额外光源一次一个StandardShadershader_feature切40StandardShaderStandardShaderGUI.cs根据UI切换参数StandardShaderStandardShaderG41StandardShader-Vert77-79初始化81-85世界空间/裁剪空间坐标88-92世界空间法线/视线94-100切空间109-112PBR预计算项Vert输出值将插值后传入Frag常见Shader优化技巧StandardShader-Vert77-79初始化42StandardShader-FragMainLightSimple获取主光源颜色/方向ndotl法向量和光源方向点积SHADOW_ATTENUATION接受阴影OcclusionOCC贴图FragmentGI全局光照UNITY_APPLY_FOG硬件雾StandardShader-FragMainLightS43StandardShader-UNITY_SETUP_BRDF_INPUTMetallic工作流输入：金属度+光滑度specColor=lerp(DielectricSpec,albedo,metallic)diffColor=albedo*lerp(1-DielectricSpec,0,metallic))Specular工作流输入：高光颜色+光滑度diffColor=albedo*(1-SpecularStrength(specColor))能量守恒金属specColor大，diffColor小非金属反之StandardShader-UNITY_SETUP_BR44StandardShader-FragmentGI250-261设置变量光照贴图或环境光263-274ReflectionProbeGPUGems3Chap.19IBLSphere无穷远Box本地校正UnityGlobalIlluminationGI核心函数StandardShader-FragmentGI250-45StandardShader-UnityGlobalGIUnityGI_BaseShadeSHPerPixel即LightProbeLightmap读取光照贴图颜色额外处理Directional实时光照贴图UnityGI_IndirectSpecularBox需要矫正反射方向根据粗糙度取mipmapStandardShader-UnityGlobalGIU46StandardShader-BRDFBRDF3_Indirect间接光的diff/spec处理BRDF3DirectSimple分为三档，套用不同BRDF近似，处理直接光照UNITY_BRDF_GI处理间接光directionallightmapsEmission自发光贴图StandardShader-BRDFBRDF3_Indi47StandardSha