Engine v5.2.5

July 26, 2026

A patch to Lume.

Physics got a big quality pass in worlds using the new physics engine — cleaner collisions, fast objects stop tunneling, vehicles handle better, and things settle instead of jittering. Busy worlds also run noticeably cheaper.
You can now stamp marks onto the world: footprints behind a walking character, skid trails behind a drifting car, splats where things land. Marks stick to the world — never to players walking through them.
Characters that floated above the ground (some imported models drew way above their own bodies) now stand on their feet, and clicking them works where they're drawn.
Saving an object into one room no longer deletes a same-named object from your other rooms — your building stays built.
Stuck rooms fix themselves instead of wedging, and games can opt into resuming exactly where everyone left off after a room recycles.
Purchases are now stamped by the server, so scripts can't fake who bought something — and as the owner you can test your own buyables for free again.
Scheduled game jobs survive restarts and can call external APIs again — daily events and webhooks keep firing.
Nameplates and other HTML labels can pin to moving things without any math, worlds with lots of tile art finish loading for new joiners, and letting go of the mouse mid-move always registers.
Press F3 for one unified debug console — everything that used to be scattered across debug panels lives in one place.
No visible change. Games with lots of scripts (and Savi's emoji in them) hold roughly 10MB less server memory per world, which means more headroom before a big world hits the per-room memory cap.
Scripts can declare how often they need to think — export const updateSchedule = { every: 10 } (or { seconds: 0.5 }) runs update() on that cadence, and near: { tag: "player", radius: 50 } lets far-away objects sleep until someone gets close. The engine skips the skipped ticks entirely — no more hand-rolled tick % N gates — and api.setUpdateSchedule({ every: 1 }) wakes a script to full speed the moment it needs it.
Worlds full of decorated, interactable-but-idle objects run measurably cooler: scripts that only react to touches, collisions, or timers no longer pay a per-tick cost at all.
If your graphics driver crashes mid-session, you now get a clear "reload the page" prompt instead of a frozen black screen — and Savi is told your screen went dark so she doesn't misread her camera tools as a game bug.
When Savi's object previews or scene views fail, the error now says why (for example, a lost graphics device), so she can tell a broken shader from a broken GPU session instantly.
No visible change. When a player's graphics device dies, the engine's internal report now names the GPU and its memory pressure at the moment of loss, so device-specific crashes get diagnosed faster.
Webhooks and external API calls from custom jobs work again in single-player rooms — fetch() inside a job script reaches the public internet with sane safety limits, so Discord pings, external leaderboards, and third-party APIs behave the way the docs always said they would. In multiplayer rooms, fetch inside a custom job keeps browser rules (CORS applies) — unchanged.
Logging a huge value (like baked geometry) from a script no longer stalls the world building megabytes of log text — you get a compact summary like [Float32Array(34992)] instead, and everything ordinary logs exactly as before.
Night skies are much cheaper to look at — starfields are now precomputed instead of recalculated for every pixel every frame, so GPU power draw no longer spikes when the camera points at a starry sky. Bright stars still twinkle live, and star brightness no longer secretly depends on your screen resolution.
Fixed a progress-wipe loop for solo players on a bad connection: if your game got stuck in a way the engine's automatic recovery couldn't fix, 5.2.4 kept retrying that recovery every ~20 seconds — and each retry reset the place, wiping your unsaved progress in your own world. The engine now tries the automatic fix exactly once; if the same stuck state comes right back, it stops resetting your world and leaves the place frozen (your local progress intact) until the connection genuinely recovers or another player can host.
Fixed lights (and other script-animated values) visibly flickering several times a minute in multiplayer games whose looks are driven by behavior scripts — spec refreshes used to briefly snap script-driven objects back to older values before the scripts re-asserted themselves.
2D characters can now stay perfectly straight while they walk. Engine-driven NPCs turn their body toward where they're going, and top-down sprites used to visibly tilt with that turn — walking villagers looked crooked or sideways. Set upright: true on a sprite (or ask Savi) and the art stays axis-aligned no matter what turns the character; cars, ships, and anything that should visibly turn keep working exactly as before.
Games can now opt into UI that holds the same size on every monitor. If your HUD was built on a big screen and looks huge (or tiny) on other displays, ask Savi to normalize it — existing layouts keep working unchanged, they just scale to match every player's screen.
Uploaded and generated (CDN) models now always get real collision shapes, even when their prepared collision shape can't be downloaded — the engine builds a collision shape from the model's own visible mesh instead of leaving a permanent invisible 1×1 m placeholder box. This ends the class of bugs where props ghost-rolled forever, players stood on invisible boxes, or objects reacted to hits with the wrong shape whenever a collider download failed.
On Mantle-physics voxel worlds, placing a block into your own character (or digging and refilling under yourself) no longer freezes you in place forever — the character now pushes out of solid blocks to the nearest opening, the way it already worked on the default physics engine. If there is genuinely no opening (fully buried), you stay put instead of tunneling through blocks.
On Mantle-physics worlds, uploaded/CDN models now collide exactly where they look like they should. Before this, a model's collision shapes floated half the model's height above its visual — balls flew through the bottom of scaled models, and dynamic models tipped and reacted strangely because their mass was centered too high.
On Mantle-physics worlds, joints now pivot exactly where you author them. Before this, every joint anchor silently shifted by half the body's height, which made motorized platforms shake objects off and hinges swing around the wrong point.
Night-sky fixes: the strange vertical chains of duplicate stars are gone (a hash precision bug), and stars stay crisp points instead of soft blobs when the engine renders below native resolution. Star brightness and layout keep their look; individual star positions reshuffle once.
The bubble over objects that are still popping in now says "Loading…" instead of making it look like your world was re-generating its stuff on every visit. Nothing is being re-made — already-created things just take a moment to download, and the label now says so. Only genuinely broken things still say "Couldn't spawn."
Your game can now declare player-settings defaults (e.g. reduced flashing on by default) and a perf ceiling in your game's settings — ask Savi to "make my game default to reduced flashing" and it's one edit.
Players' accessibility choices always win over game defaults — a player who needs reduced flashing keeps it in every game, including yours.
Dev-only conveniences finally work the way you'd expect: a script that checks api.getRoomMode() now gets the right answer everywhere — including the code that runs on each player's own machine, which used to always claim "live" even in your build room. Gate test spawners, debug HUDs, or level skips on it and they work for you AND everyone building with you, then switch themselves off in the posted game — no account checks needed.
String lights, bunting, and power cables now hang the way you'd picture them — one graceful draped line through the points you place, bulbs and flags spread along the whole run. No more surprise forest of poles around your plaza! If you do want poles under a line, say so and they'll plant themselves along the run.
Characters and machines you build from moving parts (each part moved by your scripts every tick) no longer leave a ghostly motion trail behind them — they now look just as sharp in motion as the built-in animated avatars.
Your game's UI now runs in its own sealed sandbox. Everything you could build before still works the same way — buttons, panels, saves, sounds, drawing tools, tilt controls — but a game's UI can no longer reach into or break the Spawn page around it, and a crashing UI can't take the game down with it.
When UI code does hit the sandbox wall, you get a clear message in the logs saying exactly what isn't allowed there, instead of a button that silently does nothing.
Fixed terrain brushes, path drawing, and object handles sometimes only working for a single click instead of a smooth drag in god mode. Drags now track reliably every time.
String lights got a glow-up: small warm bulbs that actually blaze, hanging under lines that sag deeper the longer the crossing — like real festoon lights across a plaza.
String lights are properly dense now — a blazing festoon of ~2-3 bulbs per meter instead of a sparse dotted line, and you can tune it with bulbSpacing if you want lanterns instead of fairy lights.

Engine v5.2.5

July 26, 2026

A patch to Lume.

Physics got a big quality pass in worlds using the new physics engine — cleaner collisions, fast objects stop tunneling, vehicles handle better, and things settle instead of jittering. Busy worlds also run noticeably cheaper.
You can now stamp marks onto the world: footprints behind a walking character, skid trails behind a drifting car, splats where things land. Marks stick to the world — never to players walking through them.
Characters that floated above the ground (some imported models drew way above their own bodies) now stand on their feet, and clicking them works where they're drawn.
Saving an object into one room no longer deletes a same-named object from your other rooms — your building stays built.
Stuck rooms fix themselves instead of wedging, and games can opt into resuming exactly where everyone left off after a room recycles.
Purchases are now stamped by the server, so scripts can't fake who bought something — and as the owner you can test your own buyables for free again.
Scheduled game jobs survive restarts and can call external APIs again — daily events and webhooks keep firing.
Nameplates and other HTML labels can pin to moving things without any math, worlds with lots of tile art finish loading for new joiners, and letting go of the mouse mid-move always registers.
Press F3 for one unified debug console — everything that used to be scattered across debug panels lives in one place.
No visible change. Games with lots of scripts (and Savi's emoji in them) hold roughly 10MB less server memory per world, which means more headroom before a big world hits the per-room memory cap.
Scripts can declare how often they need to think — export const updateSchedule = { every: 10 } (or { seconds: 0.5 }) runs update() on that cadence, and near: { tag: "player", radius: 50 } lets far-away objects sleep until someone gets close. The engine skips the skipped ticks entirely — no more hand-rolled tick % N gates — and api.setUpdateSchedule({ every: 1 }) wakes a script to full speed the moment it needs it.
Worlds full of decorated, interactable-but-idle objects run measurably cooler: scripts that only react to touches, collisions, or timers no longer pay a per-tick cost at all.
If your graphics driver crashes mid-session, you now get a clear "reload the page" prompt instead of a frozen black screen — and Savi is told your screen went dark so she doesn't misread her camera tools as a game bug.
When Savi's object previews or scene views fail, the error now says why (for example, a lost graphics device), so she can tell a broken shader from a broken GPU session instantly.
No visible change. When a player's graphics device dies, the engine's internal report now names the GPU and its memory pressure at the moment of loss, so device-specific crashes get diagnosed faster.
Webhooks and external API calls from custom jobs work again in single-player rooms — fetch() inside a job script reaches the public internet with sane safety limits, so Discord pings, external leaderboards, and third-party APIs behave the way the docs always said they would. In multiplayer rooms, fetch inside a custom job keeps browser rules (CORS applies) — unchanged.
Logging a huge value (like baked geometry) from a script no longer stalls the world building megabytes of log text — you get a compact summary like [Float32Array(34992)] instead, and everything ordinary logs exactly as before.
Night skies are much cheaper to look at — starfields are now precomputed instead of recalculated for every pixel every frame, so GPU power draw no longer spikes when the camera points at a starry sky. Bright stars still twinkle live, and star brightness no longer secretly depends on your screen resolution.
Fixed a progress-wipe loop for solo players on a bad connection: if your game got stuck in a way the engine's automatic recovery couldn't fix, 5.2.4 kept retrying that recovery every ~20 seconds — and each retry reset the place, wiping your unsaved progress in your own world. The engine now tries the automatic fix exactly once; if the same stuck state comes right back, it stops resetting your world and leaves the place frozen (your local progress intact) until the connection genuinely recovers or another player can host.
Fixed lights (and other script-animated values) visibly flickering several times a minute in multiplayer games whose looks are driven by behavior scripts — spec refreshes used to briefly snap script-driven objects back to older values before the scripts re-asserted themselves.
2D characters can now stay perfectly straight while they walk. Engine-driven NPCs turn their body toward where they're going, and top-down sprites used to visibly tilt with that turn — walking villagers looked crooked or sideways. Set upright: true on a sprite (or ask Savi) and the art stays axis-aligned no matter what turns the character; cars, ships, and anything that should visibly turn keep working exactly as before.
Games can now opt into UI that holds the same size on every monitor. If your HUD was built on a big screen and looks huge (or tiny) on other displays, ask Savi to normalize it — existing layouts keep working unchanged, they just scale to match every player's screen.
Uploaded and generated (CDN) models now always get real collision shapes, even when their prepared collision shape can't be downloaded — the engine builds a collision shape from the model's own visible mesh instead of leaving a permanent invisible 1×1 m placeholder box. This ends the class of bugs where props ghost-rolled forever, players stood on invisible boxes, or objects reacted to hits with the wrong shape whenever a collider download failed.
On Mantle-physics voxel worlds, placing a block into your own character (or digging and refilling under yourself) no longer freezes you in place forever — the character now pushes out of solid blocks to the nearest opening, the way it already worked on the default physics engine. If there is genuinely no opening (fully buried), you stay put instead of tunneling through blocks.
On Mantle-physics worlds, uploaded/CDN models now collide exactly where they look like they should. Before this, a model's collision shapes floated half the model's height above its visual — balls flew through the bottom of scaled models, and dynamic models tipped and reacted strangely because their mass was centered too high.
On Mantle-physics worlds, joints now pivot exactly where you author them. Before this, every joint anchor silently shifted by half the body's height, which made motorized platforms shake objects off and hinges swing around the wrong point.
Night-sky fixes: the strange vertical chains of duplicate stars are gone (a hash precision bug), and stars stay crisp points instead of soft blobs when the engine renders below native resolution. Star brightness and layout keep their look; individual star positions reshuffle once.
The bubble over objects that are still popping in now says "Loading…" instead of making it look like your world was re-generating its stuff on every visit. Nothing is being re-made — already-created things just take a moment to download, and the label now says so. Only genuinely broken things still say "Couldn't spawn."
Your game can now declare player-settings defaults (e.g. reduced flashing on by default) and a perf ceiling in your game's settings — ask Savi to "make my game default to reduced flashing" and it's one edit.
Players' accessibility choices always win over game defaults — a player who needs reduced flashing keeps it in every game, including yours.
Dev-only conveniences finally work the way you'd expect: a script that checks api.getRoomMode() now gets the right answer everywhere — including the code that runs on each player's own machine, which used to always claim "live" even in your build room. Gate test spawners, debug HUDs, or level skips on it and they work for you AND everyone building with you, then switch themselves off in the posted game — no account checks needed.
String lights, bunting, and power cables now hang the way you'd picture them — one graceful draped line through the points you place, bulbs and flags spread along the whole run. No more surprise forest of poles around your plaza! If you do want poles under a line, say so and they'll plant themselves along the run.
Characters and machines you build from moving parts (each part moved by your scripts every tick) no longer leave a ghostly motion trail behind them — they now look just as sharp in motion as the built-in animated avatars.
Your game's UI now runs in its own sealed sandbox. Everything you could build before still works the same way — buttons, panels, saves, sounds, drawing tools, tilt controls — but a game's UI can no longer reach into or break the Spawn page around it, and a crashing UI can't take the game down with it.
When UI code does hit the sandbox wall, you get a clear message in the logs saying exactly what isn't allowed there, instead of a button that silently does nothing.
Fixed terrain brushes, path drawing, and object handles sometimes only working for a single click instead of a smooth drag in god mode. Drags now track reliably every time.
String lights got a glow-up: small warm bulbs that actually blaze, hanging under lines that sag deeper the longer the crossing — like real festoon lights across a plaza.
String lights are properly dense now — a blazing festoon of ~2-3 bulbs per meter instead of a sparse dotted line, and you can tune it with bulbSpacing if you want lanterns instead of fairy lights.