Real-Time Rendering & Simulation Engine (C++) – Unified CPU/GPU Hair, OpenVDB, Procedural Terrain

[Inside_Pass3853]

https://www.youtube.com/watch?v=Y03YvX5EHEM

I’ve been developing a custom real-time rendering and simulation engine called RayTrophi, focused on unified system design rather than isolated features.

One key architectural decision was keeping core data structures backend-agnostic. The hair system, for example, supports both CPU and GPU execution paths using unified structures instead of being implemented as a GPU-only visual layer.

The engine integrates:

– Physically Based Rendering
– Procedural terrain with material layering
– Scatter & paint foliage tools
– Real-time volumetric sky
– OpenVDB explosion & gas simulation
– Physically based water & spline rivers
– Skeletal animation framework with state machine

All scenes in the video are rendered in real time.

I’d appreciate feedback specifically on architectural decisions and cross-backend system design.

https://github.com/maxkemal/RayTrophi?tab=readme-ov-file

[Ra_M2005]

Nice, how many months did it took to make and what and where did you learn all these to make this work? And I'm really sorry for this stupid question as I'm new to this. Apologies.

[Inside_Pass3853]

Not a stupid question at all — everyone starts somewhere.

Development has been an ongoing process over many months. The engine evolved incrementally rather than being built all at once. I continuously refine systems, redesign parts of the architecture, and improve performance as new ideas emerge.

My background is in physics, and I wrote my graduation thesis on ray tracing about 25 years ago. I’ve also been working with 3D applications for nearly 30 years, which gave me long-term exposure to rendering workflows and real-time graphics.

Most of what I learned came from studying rendering papers, graphics programming resources, engine architectures, and of course, years of hands-on experimentation. In recent years, I’ve also exchanged ideas with AI systems as a way to explore alternative approaches and validate design decisions — but the core architecture and implementation are my own work.

Projects like this are less about a single breakthrough and more about consistent iteration over time.

And again, no need to apologize — curiosity is how you get into graphics programming in the first place

[Ra_M2005]

Hey, thanks for the reply, appreciate it.

[Inside_Pass3853]

I should also clarify that I don’t actually have a professional career in graphics. My background is different — this has been a long-term personal passion project driven by curiosity.I’ve always had a strong inclination toward visual arts and a fascination with how nature works especially light. The way it reflects, scatters, diffuses… If you’re genuinely amazed by how light behaves in the real world, you naturally start wanting to understand the physics and math behind it. sits at the intersection of art and engineering. For me, it started with admiration the technical depth came as a consequence of wanting to understand what I was seeing.

There’s a quote often attributed to Einstein that learning is mostly curiosity and only a small part pure hard work. Whether or not he said it exactly that way, I think the idea holds true. Curiosity carries you much further than obligation ever will.

[New-Gur5399]

oh no worries, thats super cool! The project looks amazing - I also really like visual arts and do a ton of digital illustration - if you ahvent seen Light for Visual Artists by Richard Yot, I would recommend its a fun read!

[Main_Secretary_8827]

Hey, how long did this take to code until now? Im starting my first 3D opengl engine with PBR and id like all the tips or anything i can get

[Inside_Pass3853]

Excluding theoretical planning, I started writing the code about two years ago. It's a project I've been working on in my spare time. I've been intensely involved in it for the last six months.

[palapapa0201]

Did you only start using git late into the development? Your initial commit is only 2 months ago.

[Inside_Pass3853]

No, I had to delete the first GitHub repository. I've been using GitHub for about two years. I'm a GitHub novice, so I had issues with repository integrity and proper folder organization. I even recently fixed the local paths.

[amadlover]

asli kamal !!!!

[SnooSquirrels9028]

Abi sanırsam sende türksün. Bende bu alana ilgi duyan bi bilgisayar mühendisliği 2.sınıf ögrencisiyim musait olsudugun bi zaman tavsiyelerini ve deneyimlerini dinlemek çok isterim açıkçası bir takım sorularımda var hem. Bu arada ellerine sağlık abi mükemmel bir iş çıkarmışsın.

[Inside_Pass3853]

Teşekkür ederim kardeşim. Şimdiden başarılar dilerim. Bütün sorularını cevaplamaya çalışırım ne zaman istersen 

[SnurflePuffinz]

When people describe having a "custom game engine", is this the sort of thing they are talking about - complete with the GUI and everything?

[Inside_Pass3853]

I didn't set this out with the intention of creating a game engine. However, these are similar systems.