UE4 Ray Tracing 初探
Ray tracing (光跡追蹤)
Ray tracing 官方介紹UE4的Ray tracing(後簡稱RT)，分為"Ray Tracer" & "Path Tracer"兩部分，Ray Tracer用於計算彈跳後光線渲染之最終像素顏色，Path Tracer作為其配套工具，漸進式生成"地面真實資訊參考" (Ground Truth)，由於其公正客觀的特性，適合與ray tracing比較，便於美術與程式疊代修改參考。
System Requirements
- Operating System : Windows 10 RS5 (Build 1809) or later
- GPU : NVIDIA RTX and some GTX series cards with DXR support using the latest device drivers. [detail]
- Unreal Engine Version : 4.22 or Later
Enabling DX12 and Ray Tracing
- Project Settings > Platforms >Windows > Default RHI = DirectX 12
- Project Settings > Engine > Rendering > Ray Tracing = true
Ray tracing priority [importance level] (效果與成本綜合考量)
- r.RayTracing.Reflections [4]
- r.RayTracing.Shadows [3]
- r.RayTracing.Translucency [3]
- r.RayTracing.GlobalIllumination [3]
- r.RayTracing.AmbientOcclusion [3]
- r.RayTracing.StochasticRectLight [2]
- r.RayTracing.SkyLight [2]
- r.RayTracing.InstancedStaticMeshes [1]
- r.RayTracing.Landscape [1]
...\Config\DefaultEngine.ini
[/Script/WindowsTargetPlatform.WindowsTargetSettings]DefaultGraphicsRHI=DefaultGraphicsRHI_DX12
[/Script/Engine.RendererSettings]
r.SkinCache.CompileShaders=True
r.RayTracing=True
r.RayTracing.Reflections=1
r.RayTracing.Shadows=1
r.RayTracing.Translucency=1
r.RayTracing.GlobalIllumination=1
r.RayTracing.AmbientOcclusion=1
r.RayTracing.StochasticRectLight=1
r.RayTracing.SkyLight=1
r.RayTracing.InstancedStaticMeshes=1
r.RayTracing.Landscape=1
光柵化(raster) vs 光跡追蹤(ray tracing)
以ArchVizInterior專案為例
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使用UE4.24版本