r/Simulated • u/No-Series-2813 • 4h ago
Interactive [OC] Real-time engine simulation. What you hear is the computed exhaust pressure not samples !
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r/Simulated • u/CaptainLocoMoco • Sep 22 '18
Ever since this subreddit started getting more traction, more and more people began posting non-simulation videos. In each of these posts, users will comment something along the lines of "This is not a simulation," and an argument would ensue. So I am writing this post to, hopefully, end this never-ending cycle. I hope the mods do not remove this post, because I think it could end much of the hostility in the comments around here. Perhaps this could even be a stickied post, so all new users see it.
According to the dictionary, the word simulation is defined as, "imitation of a situation or process." However, this definition does not actually constitute what a simulation is in the world of CGI. In CGI, simulations are essentially visualizations of real-world processes that are generated using mathematical models. That is to say, the final product of a simulation is something that was created using fundamental rules of nature or some system, such as Newton's Laws of Motion, Fluid Dynamics, or various other mathematical models. In a simulation, it is often the case that each frame was created by manipulating information from the previous frame.
It's quite common for animations and simulations to coexist in one medium. There are plenty of simulated components in animated movies, such as Disney's Frozen (Snow simulation), and Hotel Transylvania 2 (Cloth simulation). However, simulations and animations individually are very different by nature. As previously stated, simulations try to model real-world processes, and use mathematical models to generate necessary data. Animations, on the other hand, are usually created through a manual process. Animators manually keyframe the attributes (position, rotation, scale, etc.) of objects in a 3D scene. It's possible for manual animations to look convincing, but that does not make them simulations.
Many 3D rendering engines use a process called "ray tracing" to create images of a 3D scene. For anyone who is unfamiliar with ray tracing, here is the definition from Wikipedia:
In computer graphics, ray tracing is a rendering) technique for generating an image by tracing the path of light as pixels in an image plane and simulating the effects of its encounters with virtual objects.
Because of this definition, many people argue that any 3D render is a simulation, so long as it was rendered using ray tracing. By definition, it is true that the process of ray tracing is a simulation. However, this argument is very silly because the entire purpose of the term "simulation" in CGI is to make a distinction between what is manually created, and what is created using the previously talked about mathematical models. Therefore, when we discuss simulated graphics, ray tracing is not considered a simulated process.
Many of these animated posts accumulate upvotes, and sometimes they stick around for a few days before getting removed. Because of this, new users who see these posts get a false idea of what a simulation actually is. Hopefully this post was informative to any newcomers. If you would like to suggest edits, please comment.
r/Simulated • u/No-Series-2813 • 4h ago
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r/Simulated • u/Due-Fudge-4889 • 1d ago
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r/Simulated • u/Fit_Revenue1928 • 3h ago
One Houdini node that builds a human body in real units (age in years, height in cm, weight in kg) and animates it from a sentence.
- Body: open-source SOMA and Anny body models, solved to hit the exact height and weight
- Shape: gender, muscle, breasts, buttocks, surface smoothing
- Motion: NVIDIA Kimodo text-to-motion, running locally on my GPU
- Path: draw a curve, and Kimodo generates the motion on it
Built by Alaa Belghith, working as Anything Visual.
Music: "Raving Energy" Kevin MacLeod (incompetech.com), licensed under Creative Commons: By Attribution 4.0 License
r/Simulated • u/sergeialmazov • 17h ago
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r/Simulated • u/bssrdf • 4h ago
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r/Simulated • u/LunderIT • 23h ago
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Hi, I'm the developer of LIT Creature Forge, a small Windows sandbox on Steam inspired by Karl Sims' 1994 evolving virtual creatures.
Each run starts with random segmented bodies and controllers. Creatures are evaluated, the better performers reproduce, and mutation and crossover change both their bodies and how they move. The gaits evolve along with the body plans.
Version 1.1 adds swimmers and competition over a cube, alongside the original land locomotion. This clip replays a saved swimming champion after evolution. Swimming uses Sims-style analytical drag, with the articulated bodies simulated in MuJoCo.
You can change the population size, trial duration and gravity, save champions, and replay them in a separate showcase. There is no creature editor, so you get to see what evolution comes up with from the starting population.
I thought it might interest people here who enjoy evolved morphology and locomotion. The Steam page has more footage and details about the sandbox:
https://store.steampowered.com/app/4701600/LIT_Creature_Forge/
r/Simulated • u/pksimshock • 21h ago
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The boat isn’t animated: everything is computed in real time in Swift (SceneKit), from the forces on the boat. Wind on the mainsail and jib (trim, reefing, apparent wind), heel, leeway, rudder, engine thrust, and waves that the hull rides. In the clip you can see a tack: the sails luff head to wind and fill again on the other side.
The 3D models, sea and sky are drawn in code too. No AI-generated graphics or video. Coast and harbours come from OpenStreetMap.
Free, no ads, no data collection. Mac, iPhone and iPad, English and Spanish.
r/Simulated • u/DigitCell • 1d ago
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Next step after the dividing cells: each amoeba is a bubble of the same foam rule. Its skin pulls taut and it keeps its area. On top of that its edge reaches out:
- By smell: food gives off a smell that spreads and fades. The edge bulges where the smell is stronger than its own average, so a pseudopod reaches towards food and the back pulls in. In blind mode it wanders at random and only finds food by touching it.
- Eat, grow, divide, starve: what it eats becomes area. Living burns that area away. At twice its size it divides, and starved to a third it dies.
r/Simulated • u/Technical-Mud54 • 2d ago
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r/Simulated • u/Optimal-Yak-9811 • 2d ago
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Try it: https://kerr-black-hole-roan.vercel.app
Real-time general-relativistic ray tracing. The disk brightens on the side moving toward you, reddens near the hole, and the stars behind it bend into an Einstein ring. Drag to orbit, scroll to zoom.
Built with Claude Code (Opus 5.5). Code: https://github.com/SkyWalkerPS/kerr-black-hole
r/Simulated • u/clainstone • 2d ago
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I'm the creator of Cbirds, a bird flock simulator that runs in the terminal, written in C99 with no dependencies and inspired by Craig Reynolds' Boids algorithm. This is its 3D mode, running in Ghostty on macOS.
How the 3D flock works: each bird only listens to its nearest neighbours, seven by default as real starlings do, instead of everyone within a radius. On top of Reynolds' three rules (alignment, cohesion, separation) there is a pull toward a roost that keeps the flock in view, and a slow drift in the air over the roost. The bands, the splits and the folds in the video all come out of those rules. The camera goes once round the flock every two minutes, and nearer birds are drawn bigger and brighter.
Everything is simulated and drawn on the CPU and sent to the terminal as images through the Kitty graphics protocol. The panel in the corner shows what a frame costs: in this clip about 15 ms to simulate, draw and send, about 54 KB to the terminal, at 59 fps. The sliders tune the simulation while it runs.
I started the 2D version in September 2025, mostly out of curiosity, after seeing antirez's C64 terminal emulator (https://github.com/antirez/c64-kitty) and a lecture by Pier Luca Lanzi on multi agent systems at Politecnico di Milano. I did get quite a bit of help from coding agents along the way. One useful thing I ended up building was a custom GIF encoder, so the agents could visually inspect the simulation and check whether their changes worked.
It also has hawks that chase the flock, multiple flocks that merge or avoid each other, text piped in that takes flight (`cat file.txt | cbirds`), Braille rendering for any terminal, and birds that fly between terminal windows.
Source: https://github.com/clainstone/cbirds
Command: `cbirds --render kitty --3d --color prism`
Install: `brew install clainstone/tap/cbirds` (also MacPorts, apt and Nix)
r/Simulated • u/Educational_Monk_396 • 1d ago
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Hey guys! Quick update on my renderer, which I've been working on and off for the past 7–8 months or so.
The library is quite opinionated about DOD (data-oriented design) and the explicit nature of WebGPU, and I've recently added support for neural inference and training.
You can now train small neural networks (MLPs), around 1–4 layers deep, using supervised learning directly as part of the library.
In the herd and wolves example below, the agents have simple behavioral rules, like chasing prey when it's nearby or fleeing when a predator gets close. The idea is to train a small model to learn these behaviors and then use it to drive the agents.
For this example, we're talking about a model with roughly 2,000 weights, so obviously not a general-purpose AI model, but enough for these kinds of behaviors.
The library also supports ONNX Runtime for working with larger models or models trained externally with something like PyTorch. For these smaller, more specialized models, though, the built-in MLP implementation will generally be faster in my use case.
Live demo (WebGPU-supported browsers only):
https://nullgraph.dev/dashboard/agents/herd-wolves-gpu
Github
https://github.com/flarelink-in/NullGraph
Another feature I've been working on is offline rendering, with a workflow somewhat similar to what's available in tools like Blender or Houdini.
It's split into two phases:
\- Compute records: Run the expensive simulation and bake the data that needs to be simulated.
\- Render records: Replay those records through the rendering execution chain using a screen texture, generating frames/tracks that can then be stitched together.
The goal is to handle simulations or visuals that would otherwise be too expensive to run in real time, or would take a long time to render, and then replay the result at 60 FPS.
I have a demo of this on my YouTube channel. The bake took up close to 30 GB of space, while the final result was around 500 MB.
Offline rendering demo:
https://youtu.be/pTD-7PCPGrg?si=vfENWIpR9YU-JEbZ
I've also added another demo to the video, this time focusing more on visual aesthetics rather than the science/simulation side.
NullGraph exists as part of a larger web-native open-world simulation runtime that I work on from time to time.
Rightn now, I'm looking into improving my neural network implementation to better match or potentially outperform ONNX Runtime for my use cases. One of the things I've noticed is that the ONNX integration can introduce a 1–3 frame delay in my current setup, along with an additional runtime download of around 6.4 MB.
I'm also starting research into co-evolution, with the goal of bringing evolutionary learning and reinforcement learning into the runtime. The co-evolution approach draws on ideas from OpenAI research and the hall-of-fame technique. I've written some design docs for this, but I'll share more once there's a working implementation to show.
One thing I'd love to get your thoughts on:
Would you guys be interested in offline rendering driven by AI prompts directly in the browser? The idea is to let you generate demos or visually complex scenes through code, spend as much time as needed baking them locally, and then replay the results smoothly. I'm also exploring ways for the system to verify its own output rather than just blindly generating code.
I'm curious whether this kind of workflow would be useful to people working on creative coding, simulations, procedural graphics, or web-based experiences.
Let me know what you think!
r/Simulated • u/jasonkeyVFX • 3d ago
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r/Simulated • u/PrinceEagle22 • 4d ago
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r/Simulated • u/JeroenDierckx • 3d ago
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After natural running, now more varied movement on different surfaces.
r/Simulated • u/LumibakoGames • 3d ago
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This is Little Bricks, a browser sandbox I made for Openbench. The horizontal demo shows building with toy bricks and then disturbing the structure with table shaking, a hammer and explosions. The falling blocks are simulated rather than keyframe-animated.
I am interested in how readable the physical behaviour feels: do unstable overhangs, toppling towers and chain collapses behave as you would expect?
Interactive demo: https://openbench.fun/bricks/, free, no installation or account. You can also save and load builds.
Development was AI-assisted; this is a recording of the running interactive simulation.
#LittleBricks #Physics #Simulation
r/Simulated • u/djbebs • 5d ago
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It’s a little physics sim I made, the jelly is calculated live so he squishes differently every time. Softer or smaller and he fits, firm and he jams at the rim.
If you want to push him through yourself: https://wobble-lab.com/experiments/plump-and-squishy/
r/Simulated • u/MozonApp • 4d ago
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I made this in Watershed, the terrain-and-water simulator I am developing. This clip shows simulated rain collecting and flowing through valleys over real elevation data. The water is computed by the simulation, rather than generated by a text-to-video model.
Time is accelerated. This is an illustrative terrain experiment, not a weather forecast or street-level flood prediction.
I am the creator. There is a free one-button Sinai demo at https://mozonapp.com/rain-demo/ (WebGPU support required). The full desktop app is paid: https://mozonapp.com/watershed/
What would you improve about the flow and pooling?
r/Simulated • u/evomusart_conference • 4d ago
The 16th International Conference on Artificial Intelligence in Music, Sound, Art and Design (EvoMusArt 2027) is accepting paper submissions.
When: 31 March – 2 April 2027
Where: Mainz, Germany
Paper Submission deadline: 1 November 2026
EvoMUSART focuses on AI and computational approaches to creativity, covering a broad range of topics, with a particular emphasis on research exploring how AI systems generate, support, evaluate, interpret, and collaborate in creative processes.
Accepted papers will be presented at the conference and published in a dedicated LNCS volume.
More information/submission details: https://www.evostar.org/2027/evomusart/
If you are working at the intersection of AI and creative practice, this may be relevant to your research. Please share with others who might be interested.
r/Simulated • u/Mangelius • 5d ago
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Instagram.com/sometimesdaily
r/Simulated • u/jasonkeyVFX • 6d ago
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The stick shape is set up as a fuel source, which gets ignited via temperature emitted from the flame
r/Simulated • u/matigekunst • 6d ago
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Part of the TouchDesigner POPtober challenge. Works in real-time. (Sorry for the wrong flair, TouchDesigner is not among them yet)
r/Simulated • u/gio_bero • 6d ago
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Would appreciate your follow on my Instagram page
r/Simulated • u/Ok_Hour_7764 • 6d ago
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This dance sequence is part of the final network simulation and quality control tests, focusing on cloth stability, collision handling, and consistent results through fast movements and sudden changes in direction.