Morrowind modders continue to astound, add object physics with 'pure lua' to a 23-year old game

What a grand and intoxicating modding community

... Ok, that is legitimately impressive, from a technical standpoint.
Lua is a high level, not exactly very 'fast', very performant language. It is designed to be very, very human readable, and coding noob friendly.
Getting a 3D physics engine to work ... in lua... is not something I would have thought possible.
Usually you need to use a much lower level language to ... actually do that.
EDIT:
A few other commenters have now pointed out that this is actually using LuaJIT... which passes Lua code to a C compiler, quickly translates and then compiles in C, and then runs in C.
So, that makes much more sense, its functionally running in C, a lower level, compiled code language.
Still impressive nonetheless!
- It is designed to be very, very human readable, and coding noob friendly
  As someone who can't wrap my head around lua syntax, I will have to assume I simply have too much coding experience
  
  I know what you mean lol, but Lua is very noob friendly... it goes fairly far out of its way to make many common functions and data types as compatible with each other as possible... so thats another way it is generally more slow, but also more forgiving, won't just totally error out and be frustrating to a beginner coder.
  
  Yeah, I remember using LUA back in the day for gmod.
  Hands down one of the shittiest languages I ever touched, right down there with PHP.
  Really puts into perspective how stupid developers can be when deciding the tools that they use.
  
  What is it that you find hard to understand about its syntax ?
- Lua is pretty fast actually, though I don't know how it compares to compiled speed.
  
  I haven't benchmarked anything in a while, so it is possible Lua is more performant now than it once was... but in my (out of date) experience, python is faster than Lua, and nearly every language that is actually compiled is... one or two or three orders of magnitude faster.
  Though it is also worth mentioning that Lua is fairly simple to plug in to some kind of database language, which can result in reasonably good performance in situations involving say... dynamically spawning or unspawning tons of inventory style minor items, or containers with them.
  Lua has been fast enough to handle a simple 2D physics engine... but this is the first time I am hearing of it handling 3D.
  
  Lua can be very fast using LuaJIT or similar
- So from what I can read, the Morrowind Script Extender uses LuaJIT instead of regular lua, which does tracing just-in-time compilation. Meaning, and I'm just paraphrasing wikipeda here, it compiles frequently executed sequeneces of operations into machine code.
  
  This appears to use OpenMW, not MWSE
  
  Now, that is a very relevant detail!
  I did not know LuaJIT was even a thing.
  Still probably not as performant as ... C++ or Rust or something, that is totally precompiled... but that would explain how this is even possible, a 3D Lua based physics engine.
  Yeah, looks like LuaJIT passes a bunch of the Lua code into C, just good ole C, and then dynamically compiles it, then runs the 'translated' C code.
  That makes a lot more sense lol.
- Imma be the guy and drop an ackshually
  Nothing about Lua would make it difficult to implement a physics engine in it compared to other languages
  The hardest part would be integrating with Morrowind's systems. If the engine doesn't expose e.g. collision geometry to scripts in an efficient way, then you'll run into some real challenges
  Even without LuaJIT, there's no reason to expect performance so bad you can't implement realtime rigid body physics. Interpreted Lua is fast, but even if it wasn't, a 60 fps performance target for physics is not tough to achieve at all
  
  Can confirm
  
  Nothing about Lua would make it difficult to implement a physics engine in it compared to other languages.
  Correct, but said implementation will be orders of magnitude slower than implementing at a lower level... meaning you cannot handle lots of objects, you can only handle a few, and only with a few players if this is all networked... otherwise you get massive physics calculation innacuracy, terrible performance spikes, crashes, and if networked, server hangs/stalls, huge desync, etc.
  The hardest part would be integrating with Morrowind's systems. If the engine doesn't expose e.g. collision geometry to scripts in an efficient way, then you'll run into some real challenges.
  I mean... that is true, that having to emulate collision meshes/hulls would be less efficient than just actually having direct access to them... but that would be the case with any language, and Lua is still much slower at any real time collision mesh/hull emulation than doing the same in a lower level language.
  Even without LuaJIT, there's no reason to expect performance so bad you can't implement realtime rigid body physics. Interpreted Lua is fast, but even if it wasn't, a 60 fps performance target for physics is not tough to achieve at all.
  You say that, but I've never seen it done well in a way that can scale for many tens or hundreds or thousands of 3D physics calls in a complex single player scenario, or a multiplayer scenario where you now also have to account for networked synchronization.
  Not saying its impossible, just saying it... I've never seen anyone pull off an efficient and accurate 3D physics engine in Lua, untill now with this LuaJIT implementation.
  If you can show me a high performance 3d physics engine written entirely in just straight up Lua, well please do show me, and share with the class.
  My guess would be that it would be constrained to either specific physics scenarios, as in, wouldn't have as full a realistic physics feature set... wouldn't handle well a lot of simultaneous intersctions... but I'm open to being surprised.
  ...
  Like uh, Godot's Jolt physics are written in C++...
  ...and while this used to basically be an addon, that was better than Godot's default physics engine...
  ...even Jolt isn't nearly as efficient or accurate as say, Valve's implementation of Havok in Source.
  Godot has been catching up with Unity on this physics engine performance front, but Unity still has the performance edge by a bit, and neither are close to Source.
  And these are all C++ physics implementations, to the best of my knowledge.
  
  Project Zombie and GMod both use Lua scripts. GMod is also one of the best physics sandboxes imo, and has like the most mods on the workshop ever.

Does anyone recall what wound up becoming of the RTX tech demo which applied Ray traced lighting to Morrowind? The old axiom holds true, any mention of Morrowind results in at least one person reinstalling it, and it appears im the guy this time.
- One day I'll do a exploit-free playthru of Morrowind. But it's not this day...
  
  Exploiting Morrowind's systems is a hobby unto itself. For years, the only copy I had access to was the Xbox release (not even the GOTY edition). Without the dev console, I had to discover other ways to bend the game to my will.
  To this day, I have to resist the urge to steal the Limeware Platter from the customs office, not to mention sequence breaking by phasing through the barrel with Fargoth's ring in that building's courtyard. Since you hadn't technically completed the tutorial and been released from custody yet, you could zip around the whole island, stealing with impunity and assembling quite the nest egg for your playthrough.

While awesome for just the technical aspect, I actually would find this to be a downgrade in the way I play, since it would mean no longer being able to make staircases out of books and pillows, as they would actually fall if they had physics. 🤣
- Cyrodillic Brandy has no physics and wont fall. Staircase away, my friend. Especially if you know how to dupe. (its ridiculously easy)

Damn, I should really play it huh
- peers suspiciously at username Hmmmm...
  Anyway, OpenMW is amazing and the best way to play the game these days. The only bad thing I can say about it is the expanded draw distance shows how tiny the world map actually is, but that's both not their fault and extremely minor considering how content dense Morrowind is.
  
  You can adjust the draw distance/fog amount in OpenMW, you know…
  
  Unless you want to mod it, then it's best to stick with the original.

I just need controllers to work in menus
- I'm shocked someone hasn't grabbed the files from the Xbox release and used their implementation as a base. It wasn't great, but it worked well enough on a controller considering how complicated Morrowind's UI was.
  
  I'm hoping the lua in OpenMW 0.49 willallow for it to be implemented. If I ever get free time I might try my hand at it.
- Controllers kind of work.
  They let you control the cursor. Actual support would be better, of course.

But useful idiots told me people won't work for free.
- What is this referencing?
  
  Every Anarcho capitalist boot licker

The article has the link buried so deep. https://github.com/MaxYari/OpenMWLuaPhysics

But do they also randomly explode all over the place when you enter a room?

So now my thief can simply stack crates to get to a store's unguarded second level instead of grinding the acrobatics skill? Nice.
I know they try to remain faithful to the original design, but I can't help but wonder how hard it would be for the OpenMW devs to integrate a full modern physics engine such as Jolt or PhysX into the engine. Probably much easier than building one from scratch in Lua of all things!
- I know they try to remain faithful to the original design, but I can’t help but wonder how hard it would be for the OpenMW devs
  I would love it if, after OpenMW hits 1.0, they set a new goal of feature parity with Skyrim (or Skywind).
  
  A post 1.0 goal is to be a general engine replacement for many Bethesda titles. OpenMW would be a platform for other projects to build OpenOblivion, OpenNewVegas, etc on.
- OpenMW already uses the bullet physics engine. However, it's not really exposed to the existing Lua API right now, hence Max Yari implementing physics separately in Lua.
  Test footage of Oblivion assets loaded in OpenMW shows that physics like ragdolls or interactive objects is already possible.

This kinda s'wit really makes my day, my n'wah

You should take a look into KSP and Rimworld modding. Adding emtirely new physics is only the cup of the cake there.
- This is a mod that only runs in a fan-made from-scratch recreation of the game's engine. Morrowind modders have basically every other game's modders beaten if you want to make it a competition.

OG programming language developed by OG Brazilian nerds implemented into OG morrowind by OG modders