UE4場景燈光優化SOP

場景燈光優化SOP

• 移除所有現有效果 (light, post-process, reflection)
• 整理level建立layer
• 檢查物件mesh, material, UV
• 重新建立主環境光源 (DirectionalLight,PostProcessVolume, SkyAtmosphere, SkyDomeMesh, SkyLight) //SkyAtmosphere在4.24之後才有
• 關閉額外效果 (Auto Exposure, Vignetting)
• 放置Lightmass importance volume
• 配置物件光源 (常見光源、IES、自發光貼花)
• 配置反射
• 配置Lightmass portal (可選)
• Bulid light (preview)
• 優化(調整或刪除非必要的光源，或是依距離動態調整光源影響範圍)
• Lightmass,postprocess參數細調
• Bulid light (production)

Light map resolution
地面、天花板、牆壁 1024
大家具 256/512
小家具 64/128

Lightmass
Static Lighting Level x Indirect Lighting Quality = 1.0 (官方建議)

測試渲染：
渲染品質:Medium
World settings - lightmass:
　Static Lighting Level = 0.6
　Num Indirect Lighting Bounces = 20
　Indirect Lighting Quality = 10
　Indirect Lighting Smoothness  = 1.1
Baselightmass.ini :
　NumHemisphereSamples = 64
　IndirectPhotonDensity = 3000
　IndirectIrradiancePhotonDensity = 1500
　IndirectPhotonSearchDistance = 180

進階渲染：
渲染品質:High
World settings - lightmass:
　Static Lighting Level = 0.4
　Num Indirect Lighting Bounces = 30
　Indirect Lighting Quality  = 10
　Indirect Lighting Smoothness  = 0.9
Baselightmass.ini :
　NumHemisphereSamples = 128
　IndirectPhotonDensity = 6000
　IndirectIrradiancePhotonDensity = 3000
　IndirectPhotonSearchDistance = 180

最終渲染：
渲染品質:Production
World settings - lightmass:
　Static Lighting Level = 0.2 (Below that we have not much impact)
　Num Indirect Lighting Bounces = 100
　Indirect Lighting Quality  = 10
　Indirect Lighting Smoothness  = 0.75
Baselightmass.ini :
　NumHemisphereSamples = 256 or 512 (above 512 will have not much difference)
　IndirectPhotonDensity = 12000 (If there are still flickers of artificial lighting, increase this value along with the parameter below)
　IndirectIrradiancePhotonDensity = 8000
　IndirectPhotonSearchDistance = 180 (180 - 240)

延伸參考資料
Scalability Reference
Unreal Engine 4 Lighting Masterclass
打光經驗分享