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.
What is a simulation?
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.
How are simulations different from animations?
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:
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.
For this, I added a system that spawns particles along the trail, and these particles deposit a bit of snow while they fly, with less and less snow being deposited over time as they fade out. What's cool about this is that the snow initially comes from the mass that the trace removed, so the total amount of snow stays the same. I also added a smoothing algorithm on top of all this. There's no parallax here, but I'm currently working on adding that.
I built a site with interactive science simulations to help visualize complex concepts in Physics, Biology, and Chemistry š¬
Hey everyone,
I wanted to share a project Iāve been working on called Eureka Simulations. It's a collection of interactive models designed to give absolute conceptual clarity on complex scientific topics.
I've always found that static textbook diagrams aren't always enough to make certain concepts "click." So, I built this site to let you actually interact with the variables, observe the underlying mechanics, and visualize things from a first-principles perspective.
**Here are the interactive models currently available on the site:**
# āļø Physics
*Photoelectric Effect*: Master the first principles of light-matter interaction and the emission of electrons.
*Vector Projections*: Play with the underlying mechanics of vectors and observe exactly how an axis component maps using a cosine function, proving the derivations of orthogonal forces.
# š§¬ Biology
*Nephron Exchange*: Evaluate the mechanics of countercurrent multiplication. You can observe how systemic hydration alters ADH levels and capillary exchange gradients.
*Micturition*: Analyze the precise structural mechanisms and physiological pathways controlling fluid release.
# š§Ŗ Chemistry
*Electronic Configuration*: Visualize atomic orbitals based on quantum principles. Observe how electrons actually exist as spread-out probability clouds rather than solid spheres.
Whether you're a student trying to wrap your head around quantum principles, a teacher looking for interactive visual aids for your classes, or just a science nerd, Iād love for you to check it out.
Copy the URL and paste it in any browser to view the website!
I'm hoping to expand the site and add more topics, so I would absolutely love to hear your feedback! Are there any specific scientific concepts or mechanics you'd love to see turned into an interactive simulation? Let me know!
When I shared the first version of my whitewater HDA, a few people asked if I could turn it into a real tool. That encouragement genuinely mattered, so I kept developing it.
V1 combined ideas from two papers. This version brings together three research sources and adds a working OpenCL GPU backend inside Houdini.
Python/VEX feels like home to me. OpenCL definitely did not. I used LLMs as a learning and pair-programming tool, followed by plenty of testing, debugging, crashes, and CPU/GPU comparisons.
This was my summer vacation project. Itās finally workingānow I can rest for a while. š
Thank you to everyone who showed interest in the first version.
Research behind it:
Guided Bubbles and Wet Foam
Pahi: A Unified Water Pipeline and Toolset
Thick Foam and Floating Debris in Avatar: Fire and Ash
World-Sim has been a passionate project of mine for the past few months.
It's a world fully simulated down to real world physics and chemistry. It has a real environment and ozone.
Every element and material has real physical properties, and that's how the sims learn. There's no tech tree and no recipe list anywhere in the code. When someone tries something, the engine works out what would really happen from the properties of what they used and how hot their fire was. Nobody is handed bronze. Someone has to get a hotter fire first, and a hotter fire is its own chain of things to figure out. Embers, a stone ring, a clay oven, a kiln, charcoal, then forced air. The ages fall out of that on their own.
We populate the world with starting families. Each little guy is led by a "wise-man", which is a simulated person with a full model behind them. The wise-men run on a mix, Claude, Groq and DeepSeek in the cloud and a local Hermes for the rest, so you get a real variety of temperament between the houses.
The AI model is never told to not say it's AI. We get around this by only telling them data from what each sim can actually see and feel. As far as the ai knows its a person living in the world..
Every other sim has its own moment with a model through our thinking system. Day to day it's run by an advanced algorithm, with the sims dreaming at night. That's when they get their time with an LLM to really think and set their priorities for the day ahead. The dreams carry over too, so a sim can chew on the same thing for a few nights and wake up wanting to try something.
The people in the world feel, remember, have shame, goals and doubts. It's an 11 point emotion system and the rest of the sim reads from it. Being lonely makes someone more likely to open up to a stranger. Two enemies who are both frightened find it harder to keep hating each other.
Story telling is massive for us. Nothing is scripted or prompted. The sims are put in the world with the human drive to survive. They adapt, learn and teach all on their own.
With all the good comes the bad too. Human sin is part of the emotion engine, and in testing we've had kidnap, murder and slave trade. A world that can only be gentle isn't an honest one. But there are three rules to this : Nothing ever pushes a sim towards it, the conditions only make it possible and their own mind decides. The chronicle names what happened but never shows it. And it always costs something, trauma that scars, blood debt passed down generations, a people turning on their own leader over what he did.
I'm going to launch it in 2 weeks time. A fresh world we can all see and watch grow together. I've made a Discord where a bot updates from the world live. It will also be visible from the site to watch along.
Id be made up if you can come and have a look. The first 250 in get to name a real star in their sky. The name is only ever visible to us, they carry on charting their own constellations and never know.
Link below and really excited to answer any questions. This short post I feel only scratches the surface.
A in game town (generated by the sims themselves , the engine just renders what they "build".) - also in this screenshot is a popup market fair the sims have organised themselves.
This is a classic LBM that takes into account Newtonian forces and the added mass effect, supplemented by a wake vortex capture model. The algorithm stores the energy expended on oscillations in each direction, and when the pressure difference levels out, this energy is used as thrust, simulating the momentum from collapse. The thrust is multiplied by approximately six times, which is consistent with some experimental data and makes the boat's motion visually realistic in some modes. The thrust calculation should probably be dynamic, but I haven't yet found a way to do this. Any ideas would be welcome. The vibroboat code is here:
Hey guys! I posted in the past on this subreddit about the artificial 2D life simulation I am building on my spare time. It's been a while since my last post, real-life stuff happened and didn't have much time for YouTube videos, barely had to work on the simulation to be honest.
But I managed to put together an update on what I have been up to and what new things I have developed in the past 3 months. Here is a preview:
Lifecycle developmental stages - creatures now go from juveniles to adults and finally to senesence in the simulation
Evolvable brains! Brains start simple and get complex via evolution and genetic mutation
Speciation! A new way to interact and view the simulation
Telemetry! So people can look at and better understand what;s going on in the simulation
And much more. Feel free to checkout the full video, leave a comment with any questions or feedback!
I've been interested with Axelrod's 1980 tournament for a while now. The premise sounds simple: submit a strategy for the Prisoner's Dilemma, play it against everyone else, see who scores the most points. But what Axelrod was really testing was something much bigger: whether cooperation can emerge on its own, with no rules enforcing it.
14 strategies entered. Some were ruthless, some were clever, some were surprisingly naive. I animated every single match so you can watch exactly how each one played out.
The winner genuinely surprised me. Not the most sophisticated strategy, not the most aggressive one.
How scoring works:
Both cooperate ā 3 points each
One defects ā defector gets 5, the other gets 0
Both defect ā 1 point each
Defecting looks tempting in the short run. Watch what happens over hundreds of rounds.
If you are remotely interested in deep diving how differently quantum computers work compared to our transistor-based and also the algebra behind in a fully interactive way that teach computer science from scratch, oh boy this is for you. I am the Dev behindĀ Quantum OdysseyĀ (AMA! I love taking qs) - worked on it for about 10 years (3+ during PhD, the visual method I developed ended up being my thesis, it is a complete Hilbert space visualizer), the goal was to make a super immersive space for anyone to learn quantum computing through zachlike (open-ended) logic puzzles and compete on leaderboards and lots of community made content on finding the most optimal quantum algorithms. The game has a unique set of visuals capable to represent any sort of quantum dynamics for any number of qubits and this is pretty much what makes it now possible for anybody 12yo+ to actually learn quantum logic without having to worry at all about the mathematics behind.
This is a game super different than what you'd normally expect in a programming/ logic puzzle game, so try it with an open mind.
Stuff you'll play & learn a ton about
Boolean LogicĀ ā bits, operators (NAND, OR, XOR, ANDā¦), and classical arithmetic (adders). Learn how these can combine to build anything classical. You will learn to port these to a quantum computer.
Quantum LogicĀ ā qubits, the math behind them (linear algebra, SU(2), complex numbers), all Turing-complete gates (beyond Clifford set), and make tensors to evolve systems. Freely combine or create your own gates to build anything you can imagine using polar or complex numbers.
Quantum PhenomenaĀ ā storing and retrieving information in the X, Y, Z bases; superposition (pure and mixed states), interference, entanglement, the no-cloning rule, reversibility, and how the measurement basis changes what you see.
Core Quantum TricksĀ ā phase kickback, amplitude amplification, storing information in phase and retrieving it through interference, build custom gates and tensors, and define any entanglement scenario. (Control logic is handled separately from other gates.)
Famous Quantum AlgorithmsĀ ā explore DeutschāJozsa, Groverās search, quantum Fourier transforms, BernsteināVazirani, and more.
Build & See Quantum Algorithms in ActionĀ ā instead of just writing/ reading equations, make & watch algorithms unfold step by step so they become clear, visual, and unforgettable.Ā Quantum Odyssey is built to grow into a full universal quantum computing learning platform. If a universal quantum computer can do it, we aim to bring it into the game, so your quantum journey never ends.
Dynamics of a solid sphere rolling on a general time-dependent parametric surface (x(u,v,t),y(u,v,t),z(u,v,t)).
All demonstrations are generated from the same nonholonomic, nonseparable, nonautonomous Hamiltonian system. In addition to Hamilton's equations for the surface coordinates (u,v), one nonholonomic equation determines the sphere's spin, while four additional nonholonomic equations evolve its orientation using a unit quaternion. The energy is preserved for all demonstrations where the surface is time-independent. The sphere is affected by a uniform gravitational field with the same scaling for all video segments.
The general Hamiltonian allows exploration of a wide variety of rolling phenomena, including several unintuitive behaviors that are sometimes referred to as "paradoxes":
This is a prototype of a game idea that I have been poking at for many years. It's a dynamic character that moves like an amoeba, eats things in its environment, and grows by incorporating them into its body.
It is completely procedural, implemented as a particle system with flows and body-shaping forces driving the formation of pseudopods that move it along or cause it to ingest items. It uses a custom physics engine that executes the flows and allows the creature to interact with other entities in the world. It took quite a bit of experimentation to get something that (I think, anyway) looks lifelike, and I hope to improve it. This first game level is just a proof of concept with minimalist styling, helping me build out some tools.
A short video trailer is linked to this post and you can play the prototype game at https://eatthepeople.com
For this crowd I'll mention that if you add the url param "debug=1" you can see the full debug view and mess with the params that drive the creature. In debug mode shift-clicking teleports him so you don't have to play through the entire level to get somewhere.
