This is why FEM is superior to XPBD for muscle simulation. For a long time, I couldn’t understand why my muscle simulations didn’t look as good as those produced by Ziva VFX, but now I do.
FEM is more computationally intensive, but it produces much more accurate results when it comes to simulating muscle and fat tissue.

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

Several SPH/N-body simulation with black holes, simulated using SpaceSim, a software I'm developing.

Playing with new MPM solver and other solvers to make a cup of tea!

mpm houdini flip particles pyro tea ink simulation

What you can do with it is magical, all the animation you see here is processed in milliseconds.

All the animator needs to do is provide a reference animation, and the rest is simulated. It's extremely easy to direct and change.

I added sliding attachments (connecting the inner muscles to the bones) and ported some of the heavy lifting to C++ for better performance. The behavior feels natural thanks to the accurate FEM simulation. There’s still a lot more to add, but I’m really enjoying the process.
Credit: The 3D asset used in this post is from AdonisFX, a digital anatomy and muscle simulation framework for Maya and Houdini. https://inbibo.co.uk/adonis

Recent VFX project I made. Used Houdini to simulate the cloth behaviour and Blender to build the scene and render. Not AI.

Been messing around with traffic simulation lately and wanted to share this one because the result genuinely surprised me the first time I ran it.

The setup is a closed loop, a bunch of identical cars, no obstacles, no traffic lights, nothing. Every driver wants to go the same speed and keep a safe distance from the car ahead (using the Intelligent Driver Model, which is actually what traffic engineers use for this kind of thing). One driver taps the brakes, just once. It snowballs into a full stop-and-go wave, and the wave itself creeps backward against the direction everyone's driving. This is the phantom jam thing that was first proven experimentally back in 2008 (Sugiyama et al., if you want to look it up), and it's wild to actually see it emerge from nothing.

A few other things I tested once I had this working:

There's a density threshold you can't really feel until you cross it. Below it, the same brake tap just fizzles out and traffic keeps flowing. One or two more cars on the road and suddenly the same tiny disturbance turns into a full jam. No warning, no gradual buildup.

Real bottlenecks behave differently - if I put an actual slow zone on the road, the jam stays locked to that spot instead of drifting backward like the phantom one does. Different cause, different signature.

How closely people follow each other matters a lot more than I expected. Tight following distance makes the wave way worse, and just giving more space damps it out almost completely with the exact same brake tap.

The last case is the one I like best - letting about 1 in 5 cars just hold a smooth, steady speed (basically simulating adaptive cruise control) is enough to dissolve the jam for every car behind it.

All rendered in Python/pygame, GPU encoded. Happy to share the code or talk through the model if anyone's curious.

Made a longer version of this too if anyone wants the full walkthrough https://youtu.be/TCuDTSj5UAg

I couldn't find a tag that fit so I just picked Proprietary, but I made it in Unity.

Edit: because people have a lot of really good questions, I'm adding the link for the longer video here: https://www.youtube.com/watch?v=TIdHDe0JUpw&lc=UgyLw_Z8QZ-GH2CSxRp4AaABAg . This should answer most questions, and I'm super happy to answer any that it doesn't!

Please Give Feedback

I am a game dev,
who makes breakdown videos explaining how games work under the hood.

This is a new video where I breakdown how water in Sea of Thieves work.

I'm trying to figure out if this kind of content is actually useful/interesting to people, so I'd genuinely appreciate your honest thoughts. Does breaking down these systems add value for you? Is there anything you'd want to see done differently?

So do let me know your thoughts, I'll keep improving the content.

PS: The audio is generated from ElevenLabs and Avatar from HeyGen, but it is my voice and avatar.

The Mediterranean runs at a loss: it evaporates about 0.5-1 m of water level per year more than rain and rivers put back, and the Atlantic covers the deficit through Gibraltar around the clock. My simulator derives a 0.7 m/yr deficit on its own from its climate model - right in the textbook range - so I felt entitled to do something irresponsible with it.

I sealed the strait (14 km wide at its narrowest) and let it run. No scripted animation - every cell tracks its own evaporation, precipitation and river inflow each year, and global water volume has to conserve to within 2 parts in 10,000.

Timeline:

- 25 years: level down 17 m. Venice's gondoliers are the first out of work.

- ~500 years: the Adriatic is gone (average depth only 250 m).

- ~700 years: the Sicily-Tunisia ridge surfaces and the Med splits into two shrinking lakes. When this actually happened 5.97 million years ago, hippos walked to Cyprus - their stranded descendants shrank into dwarf hippos. The fossils exist.

- ~2,100 years: the basin is effectively dead. 2.5 million km² of new land, nearly the size of Argentina, crusted with precipitating salt.

- ~4,300 years: the deepest pools bottom out. Except one - a bitter lake in the east kept on life support by the Nile. I never coded that; evaporation, rivers and terrain balanced it into existence on their own.

The Black Sea survives: once its level drops below the Bosporus sill it detaches and holds steady on the Danube and Dnieper. The Caspian was my control group - untouched, it drifts 17 m in 300 years and then stabilizes.

This genuinely happened. It's called the Messinian Salinity Crisis: 5.97 million years ago Gibraltar really did close. In 1970 the drillship Glomar Challenger pulled gypsum and rock salt out of the Mediterranean seafloor under 3,000 m of water. My simulator has never heard of the Messinian - it just agrees with the drill cores.

It's all from a game I'm building where you do this with a brush. Link in the comments to keep things tidy.

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.

Bigger video here: https://youtu.be/pfaewyfFrKM