Hey hey, what’s crashing?
Certainly, this experimental package. But before it does, it gives you a glimpse into Nvidia’s vision of what is arguably the fastest real-time path-tracing renderer to date. It allows rendering 4K output at almost 60 fps on a laptop with an RTX 4090 mobile GPU (DLSS enabled).
To make this work in the current vvvv gamma, first, a DX11 to DX12 bridge had to be created, which casually gives you access to all new shader types (mostly untested, but should work) today (thanks claude!). You have to write plain HLSL, so no SDSL convenience there, but that will hopefully come with a DX12 switch of Stride in vvvv later this year.
But for the brave, go ahead:
nuget install vl.nvidia.pathtracing -pre
Scene Graph
The nodes are quite similar to the Stride scene graph nodes, but internally, it basically resolves into one giant shader. Changing the graph at runtime results in flashes (buffer resets and acceleration structures rebuild) and is not recommended. Think of it this way: you tell the GPU what models and materials exist, and the rest is instancing. The vvvv nodes give you a convenient way to organize and express that.
You get primitives (Plane, Box, Sphere), plus CPU and GPU instancers. The GPU instancer is a compute shader that you can write, which creates these instances with simple HLSL methods.
There is also a UI for the extensive settings you can open/close, as well as nodes for these settings, if you need to control some from the patch:
Technical Features
- RTXPT path tracing: ReSTIR DI/GI with RTXDI reservoir-based light sampling
- DLSS Super Resolution + Ray Reconstruction: DLSS-RR replaces the denoiser at quality presets
- SER: Reorders shader execution to achive better performance
- NRD denoising: ReLAX/ReBLUR for non-DLSS-RR modes
- DX12 Bridge: DX11/DX12 interop, so all of the above works inside vvvv gamma today
Requirements
- Minimum: RTX 30 series (Ampere)
- Recommended: RTX 40 series (Ada)
- RTX 20 series (Turing) has DXR support and may run
- Latest drivers that support shader model 6.9
Licensing:
Free for non-commercial use if you post output on social media and credit vvvv and me. Contact me for a commercial license.
Credits:
Based on RTXPT, a project by Filip Strugar of Nvidia.
Now let me see what this thing can do and how it goes on your machine. I’m pretty sure there is more to it than these debug help patches:
Cheers!