Awesome
RTX Global Illumination in Unity
Introduction
This respository is RTXGI-DDGI implementation in Unity 2022.3.17f1c1 with URP14.0.9
It use Microsoft DirectX Raytracing to trace ray from each probe to scene geometry, grab irradiance and evaluate into texture
System Requirements
This renderer feature need DXR capable GPU, and you need to enable DirectX12 Graphics API on Windows in unity
Limitations
This is more like a demostration, we have some limitations here.
- Only DirectX12 API is supported on Windows
- Only one probe volume supported
- We use FindObjectsOfType to grab scene lights in each frame, it may be expensive
- Transparent object is not tested at this version
Warning
-
This feature is only tested on NVIDIA Cards (NVIDIA Geforce RTX 4070 Ti)
-
Probe Variability Feature is expermential, it dont support emissive materials, it means if you change emissive object, illumination will keep as converged.
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You may got bug like this (scene suddenly got full black), i think it's because of Shader Keywords, but i haven't solved it yet.
<img src="./Notes/images/sponza_2.png" alt="sponza_2" style="zoom:33%;" />- This bug will not appear at playing state
- If you got it, you can click Volume->DDGI->Refresh DDGI Settings, or just change code in
LitRaytracingForwardPass.hlsl:
// Raw code
#ifdef DDGI_SHOW_INDIRECT_ONLY
color.rgb = indirectLighting;
#elif DDGI_SHOW_PURE_INDIRECT_RADIANCE
color.rgb = indirectRadiance;
#else
color.rgb += indirectLighting;
#endif
// Changed code (skip keywords)
color.rgb += indirectLighting;