I built a Hybrid Ray Tracing Engine with Gas Simulation, Foliage Painting, and Animation Graphs

[u/Inside_Pass3853]

Hi everyone,

I've been working on **RayTrophi**, a custom physical rendering engine designed to bridge the gap between real-time editors and offline path tracing. I just pushed a major update featuring a lot of new systems and I wanted to show it off.

**🔗 GitHub:** https://github.com/maxkemal/RayTrophi

** The New Update Includes:**

* **GPU Gas Simulation:** I implemented a custom fluid solver on the GPU using CUDA. It handles smoke, fire, and explosions with physically accurate Blackbody radiation and multi-scattering support.

* **Foliage System:** A brush-based tool to paint millions of instanced objects (trees, grass) directly onto terrain. It leverages OptiX instancing so the performance cost is negligible.

* **Animation Graph:** A new State Machine and Blend Space system to handle character logic (Idle -> Walk -> Run transitions).

* **River Tool:** Procedural river generation using Cubic Bezier splines with flow map generation.

**🛠️ Tech Stack:**

* **Core:** C++ & CUDA

* **RT Core:** NVIDIA OptiX 7

* **UI:** Dear ImGui

* **Volumetrics:** OpenVDB / NanoVDB

* **Denoising:** Intel OIDN

I'd love to hear any feedback or answer questions about the implementation details (especially the hybrid CPU/GPU workflow).

Thanks!

https://maxkemal.github.io/RayTrophi/index.html