v0.117.0-rc19 Whole Worlds

Everything in rc16, plus saves that never stall a frame or lose a player's data, a warm-up that prepares a level without crowding it, and terrain answers that stay true once they say they are final.

Saves

• Saving no longer costs the frame. A save is encoded and written in the background, and only the keys that changed are encoded again. save.set of a large table is about twice as fast.
• A save is written to a temporary file and moved into place, so a crash or a killed game leaves the previous save whole. user:// files are written the same way.
• A save slot that cannot be read is kept beside it as save/<slot>.ron.unreadable with a Console error, instead of being written over by the next save.
• save.flush() hands the save off and returns at once. save.flush({ wait = true }) returns once it is on disk. Stopping Play and quitting always wait.
• A slot still holds up to 4 MB. For larger player-made data, write user:// files with assets.writeJson or assets.writeBytes; the slot's error now says so.

Warming a level

• assets.warm prepares pictures on a few workers and shaders one at a time, instead of a thread per asset, so warming a large level no longer crowds the frames around it.
• An asset used while it is still warming is finished, never prepared a second time.
• UI and screen shaders can be warmed as well as material shaders. Sky and distance-field shaders cannot yet, and come back in the call's failed list with the reason.
• Warmed shaders are installed one a frame, and the time shows as shaderInstall and materialBind in perf.parts.

Terrain answers that stay true

• terrain.raycast says exact only when nothing along the ray could still change, and a ray that misses over ground not yet made answers nil, "unknown" instead of "air".
• terrain.prepare works on a moving world, waits for a world that is not loaded yet instead of being dropped, and keeps all the ground it asked for. terrain.ready then stays true there.
• A paint over coarse stand-in ground makes that ground for physics and queries too.

Upgrading

Projects upgrade themselves; nothing to do. What upgrading cannot change for you:

• assets.getContents and assets.getFile return paths relative to the project (levels/one.ron), not full paths on disk, so a listed file can be passed straight to assets.readText. A script that worked out the project folder from these paths needs another way.
• save.flush() returns before the save is on disk. A script that reads the save file itself right after flushing should call save.flush({ wait = true }).