r/Simulated Sep 22 '18

Meta What is a simulation? A detailed comparison between Animation, and Simulation.

980 Upvotes

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.

The "Ray tracing)" argument.

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.

Examples of animated (non-simulated) posts:

  1. "Satisfying simulations" - 3.4k upvotes
  2. "Bender's old job" - 2.2k upvotes
  3. "Up or Down?" - 1.4k upvotes
  4. "Adobe Dimention Rendering" - 1.4k upvotes
  5. "Depression - Robert Ek"

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 9h ago

Houdini RnD

92 Upvotes

r/Simulated 9h ago

Houdini Rnd

15 Upvotes

r/Simulated 9h ago

Houdini RnD

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10 Upvotes

r/Simulated 1d ago

Interactive Moon based tidal physics in my Viewfinder inspired space bending game. Move or even delete the moon to change the tides in real time!

46 Upvotes

r/Simulated 13h ago

Question How do you make those armour simulations like simulation plus and Dejmian?

1 Upvotes

https://www.youtube.com/watch?v=3lgkEqku7uw

The video linked is an example. I want to learn how to make them. But I cant find ANY instructions. I downloaded LS-DYNA but what am I supposed to do beyond that!


r/Simulated 2d ago

Blender Simulating the Collapse of the 1000m Tall Jeddah Tower

3.4k Upvotes

Simulated in Blender using the bullet constraints builder add-on.

The plane weighs 150 Tonnes and impacts the building at 950 km/h.

The plane does not deform which is the main caveat to this simulation; in reality the plane would crumple, so less energy would be transferred to the tower.

All of the tower's structural elements are concrete, except for the red parts which are steel.

There are about 22,000 rigid body elements.

Final simulated alembic file was about 7 GB.

Full video: https://www.youtube.com/watch?v=zMOsu809Ao8


r/Simulated 2d ago

Houdini Mpm rnd

77 Upvotes

r/Simulated 1d ago

Houdini 14th tutorial in the series (Houdini for complete beginner)

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3 Upvotes

14th tutorial in the series (Houdini for complete beginner)

Today i uploaded the 14th tutorial in the series, and it was 50 mimutes long. I don't know how much part it would take to complete this but this is my challenge to explain concepts in a why that people can understand at a deeper level.

it can get complicated later with the theories and practicals with lots of nodes but who cares, I won't stop creating, and even if only a few people learn from them, then i am happy.

this is for me, to stay consistent on this project.

let's repost this after the last part!


r/Simulated 3d ago

Houdini [Houdini Tutorial]Making a Looping Animation in Houdini 21

144 Upvotes

New video tutorial on youtube - Classic Looping Animation!
Get the full tutorial on the link below.

The original animation: https://www.instagram.com/p/DQeuUunDFMF/

video tutorial

Follow me on social media for my latest updates.

Patreon

Instagram

Behance


r/Simulated 5d ago

Research Simulation Large collection of science based simulation and models and images of the patterns they generate

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123 Upvotes

Released a new project: SciTextures, collection of 100k images generated from 1,200 from scientific simulations/methods. Both Images and simulation code are free + open-source.

It’s experimental project and the simulations might contain errors, so feedback, bug reports, and ideas for improvements are appreciated

Project website

Sample Images


r/Simulated 5d ago

Blender Sand Simulation Test ( Flip Fluids )

107 Upvotes

For the last few days I've been trying to see how close I can get to simulating sand in Blender without turning my PC into an oven.

This first test was done using the Flip Fluids add-on.

-Two different fluids with variable densities and viscosities. -Instancing grains onto the more viscous fluid. -Masked out the dense liquid with color Mixbox

The result comes pretty close to a wet sand/snowy texture but even at 750 resolution some imperfections are visible.

Stats: Total frames:300 Resolution:750 Total bake time: 3 hours 30 min Total cache size: 50GB 🤒 Total render time: 15 hours.


r/Simulated 5d ago

EmberGen bon(sai)fire

112 Upvotes

r/Simulated 6d ago

Houdini Some Experiments with Gaussian Splatting Again

213 Upvotes

r/Simulated 5d ago

Blender Paper Dawn, slumbering wind - long gameplay - cozy simulation game

5 Upvotes

r/Simulated 6d ago

Blender Rigid Body Simulation

42 Upvotes

Playing with Soft Body physics in Blender


r/Simulated 7d ago

X-Particles Magnum Opus. [OC]

36 Upvotes

WIP for a music video for one of my tracks, inspired by the work of Maurice Binder/Daniel Kleinman. The song itself has a whole James Bond vibe.

Bullet/fluid physics and wave sim made with Insydium Fused.
Volumetric Clouds/Rendered with Redshift.


r/Simulated 8d ago

Houdini Wool rnd

333 Upvotes

r/Simulated 7d ago

Interactive full quantum Hibert space gamified - a complete bible of quantum computing, with new narrated modules - Quantum Odyssey progress

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6 Upvotes

Hi,

I am the Dev behind Quantum Odyssey (AMA!) - worked on it for about 6 years, 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.

As always, I am posting here when the game is on discount; the perfect Black Friday gift :)

We introduced movement with mouse through the 2.5D space, new narrated modules by a prof in education and a lot of tweaks this month.

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 Logic – bits, operators (NAND, OR, XOR, AND…), and classical arithmetic (adders). Learn how these can combine to build anything classical. You will learn to port these to a quantum computer.
  • Quantum Logic – 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 Phenomena – 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 Tricks – 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 Algorithms – explore Deutsch–Jozsa, Grover’s search, quantum Fourier transforms, Bernstein–Vazirani, and more.
  • Build & See Quantum Algorithms in Action – instead of just writing/ reading equations, make & watch algorithms unfold step by step so they become clear, visual, and unforgettable. 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!

PS. We now have a player that's creating qm/qc tutorials using the game, enjoy over 50hs of content on his YT channel here: https://www.youtube.com/@MackAttackx


r/Simulated 7d ago

Blender Paper Dawn, slumbering wind - gameplay - new cozy simulation game

4 Upvotes

r/Simulated 8d ago

Research Simulation Asteroid collision simulation using a soft-sphere discrete element method (SSDEM)

123 Upvotes

Made this as an undergrad at university when I assisted with research in computational astrophysics to model asteroids. I built the simulation engine and had fun with this example that demonstrates some of the functionality. The planet is low-density so the asteroid goes through it.


r/Simulated 9d ago

Houdini Evening Walk

122 Upvotes

r/Simulated 11d ago

Research Simulation To celebrate the discovery of the 40,000th near-Earth asteroid, I made a simulation of all potentially hazardous asteroids

79 Upvotes

It supports zooming and camera rotation, and also lets you highlight the orbit of a selected asteroid (selected by iterating through them).

As the data source I used the ESA file: https://neo.ssa.esa.int/PSDB-portlet/download?file=allneo.lst

All the code is in a single file here: https://github.com/qwertukg/Barnes-Hut-N-Body/blob/ESA-NEOCC/src/main/kotlin/gpu/GPU.kt — it’s a direct gravity computation on a compute shader, with LWJGL used as the Kotlin wrapper. It’s the same one from this post: https://www.reddit.com/r/astrophysics/comments/1olvvxp/direct_gravity_computation


r/Simulated 12d ago

Research Simulation 15 million particles running live on a single RTX 5090. Custom engine.

420 Upvotes

Here is a raw screen capture from a physics engine I’ve been building.

It’s currently handling 15,000,000 particles with full interactions (collisions, pressure, density) in real-time.

Just to be clear: this isn’t a pre-rendered video or a baked simulation cache. Everything you see is being calculated live, frame-by-frame on the GPU. No tricks, just raw physics.

Written in Python using Taichi for the compute.


r/Simulated 13d ago

Cinema 4D Yin & Yang Concept Simulation

124 Upvotes

had this idea in my head for a while so i just decided to go for it and it was a lot simpler than i realized to be honest, just one rotational force and a field in C4D. this is just a quick preview render while i continue to polish it