IVivanjermakov·Aug 11, 2026
Jolt Physics: https://github.com/jrouwe/JoltPhysics
In Jolt: Clojure compiler implemented with Chez Schemejrouwe
JoltPhysics
C++2022–2026
jrouwe / JoltPhysics
JoltPhysics
A multi core friendly rigid body physics and collision detection library. Written in C++. Suitable for games and VR applications. Used by Horizon Forbidden West and Death Stranding 2.
12Distinct people
16Mentions
0Explicit recommenders
12.3KGitHub stars
What to know before exploring
What it is
A multi core friendly rigid body physics and collision detection library. Written in C++. Suitable for games and VR applications. Used by Horizon Forbidden West and Death Stranding 2.
GitHub
Where it is used
No documented product use was verified in the last source check.
What people are saying
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Also in these discussions
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This week on Hacker News
Nov 8–Nov 15 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/15/2026, 6:36:16 PM UTC.
No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.
Mentions over time
HN mentions by year16 dated mentions
Observed mentions: 2022-03-10 00:51:51 UTC to 2026-08-11 16:34:53 UTC.
* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| 2022 | 2022-01-01 00:00:00 UTC | 2023-01-01 00:00:00 UTC | 4 | 2 | 2 |
| 2023 | 2023-01-01 00:00:00 UTC | 2024-01-01 00:00:00 UTC | 4 | 0 | 4 |
| 2024 | 2024-01-01 00:00:00 UTC | 2025-01-01 00:00:00 UTC | 2 | 2 | 0 |
| 2025 | 2025-01-01 00:00:00 UTC | 2026-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2026 (partial) | 2026-01-01 00:00:00 UTC | 2027-01-01 00:00:00 UTC | 6 | 0 | 6 |
What Hacker News says
6 sourcesNote: this involves blockchain VMs. If that's a dealbreaker, feel free to skip. I get it.
I've spent 8 years working on RISC-V VMs for blockchains, recently also contributing to ZK VMs. Modern blockchain VMs are drastically more powerful, and I'm curious how far we can push them. I started porting real game logic to blockchain VMs, running game loop, physics simulation, collision detection, etc., on blockchain VMs. So far I have:
* Teeworlds to CKB-VM: https://xuejie.space/2026_06_16_teeworlds_on_ckb/
* One Hour One Life to CKB-VM: https://xuejie.space/2026_06_29_porting_one_hour_one_life_ga...
* A small ray tracer to Jolt ZK VM: https://xuejie.space/2026_07_10_cpp_ray_tracer_on_jolt_zk_vm...
Source is available for 2 of the 3, I need to clean up the OHOL one.
Some context: CKB-VM [1] is a RISC-V virtual machine I designed for Nervos star
Read the rest
ting in 2018. Jolt ZK VM [2] is a zero-knowledge virtual machine developed by a16z. Both execute RISC-V code, but due to different design, Jolt ZK VM is a much faster CPU than CKB-VM.
Technically this is a fun challenge. Many techniques I used resemble game development tricks from the 90s on game consoles: fixed point math, banked memory in ROMs, aggressively inlining tricks, etc. I want to push to see where the ceiling is. Right now I'm trying to get a Godot [3] + JoltPhysics [4] game loop running on Jolt ZK VM.
Happy to answer questions about the VM internals, the porting process, or anything in general.
[1] https://github.com/nervosnetwork/ckb-vm
[2] https://jolt.a16zcrypto.com/
[3] https://godotengine.org/
[4] https://github.com/jrouwe/JoltPhysics
About Jolt, do you mean https://github.com/jrouwe/JoltPhysics ?
In Box3D, an open source 3D physics engine> Today the options are either free and open source (which can be extremely high quality, like Jolt: https://github.com/jrouwe/JoltPhysics)
I did mention this was changing in particular with physics engines. That being said, proprietary dependencies still reign supreme in places like audio engines. Something like OpenAL isn't really a replacement for FMOD or Wwise. I know those off-the-shelf engines roll their own replacements, but then they also roll their own pathfinding and navmesh generation as far as I know.
In Testing the Swift C compatibility with Raylib (+WASM)Pathfinding middleware has traditionally been a thing though, e.g. apart from the mentioned ReCast (which is the popular free solution) the commercial counterpart was PathEngine (looks like they are even still around: https://pathengine.com/overview/).
If you need to do efficient path finding on random triangle geometry (as opposed to running A* on simple quad or hex grids) it quickly gets tricky.
What has undeniably declined is the traditional "10k US-$ commercial middleware". Today the options are either free and open source (which can be extremely high quality, like Jolt: https://github.com/jrouwe/JoltPhysics) or fully featured engines like Godot, Unity or UE - but little inbetween those "extremes".
In Testing the Swift C compatibility with Raylib (+WASM)The physics engine mentioned towards the end, Jolt Physics [0] is used in the frankly blockbuster games Horizon: Forbidden West and Death Stranding 2 and yet opens its description with
> Why create yet another physics engine? Firstly, it has been a personal learning project.
which is really rather wonderful and inspiring to see.
[0] https://github.com/jrouwe/JoltPhysics
In I'm making a game engine based on dynamic signed distance fields (SDFs) [video]