A placed model's client (1.10.64, UGCUSE3DSERVICES=7:0) always loads its
blueprint's NIF and HKX (its BlueprintComponent sets renderUserGen and
physicsUserGen itself) and its LXFML, asks the world for each file's
manifest first and waits for the answer with no timeout.
With ugc_manifest=1 and the new ugc_manifest_models=1 (default 0) the world:
- leaves the models whose mesh the UGC server made out of the LXFML it
sends when a property loads,
- answers their NIF with the UGC server's checksum, their LXFML with the
stored LXFML's (worked out once and kept) and their HKX as not known,
- sends a model that isn't made its LXFML (once for the three requests),
so the client builds it itself and no model is left waiting.
When the UGC server writes a model's mesh with a new checksum it sends
UGC_MODELS_MADE (a new master message, appended) to the master, which
passes it to every world; a world with that model placed sends its
players the new NIF checksum and NotifyClientUGCModelReady (game message
909, the blueprint id), so clients switch to the served mesh.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
With UGCUSE3DSERVICES=7:0 (the client's default) the client asks its world for
a blueprint file's MD5 and size (REQUEST_UGC_MANIFEST_INFO, world 27) and then
downloads BrickModels/UserMade/<id % 1000>/<id>.<ext>.sd0. Layouts checked in
the 1.10.64 client: the request is a u64 blueprint id and a u8 resource type;
the answer (UGC_MANIFEST_RESPONSE, client 60) repeats them and adds a u8 valid,
the u32 size and the 16 byte MD5 of the inflated file, 37 bytes after the 0x53
exactly or the client drops it.
- dNet: WorldPackets::RequestUgcManifestInfo, ClientPackets::UgcManifestResponse
(eUgcResourceType), with byte tests against the client's layouts.
- Database: ugc_file_checksums (per model or module combination and file) and
ugc_modular_build.combination_id (migrations 89 / 72), GetUgcFileChecksum
looks a blueprint up as a model, else as a build through its combination.
- UGC server: every download is also written as .sd0 (Sd0::Compress); workers
hand the checksums back and the main thread stores them; old items get their
sd0 icon and checksum, and builds their combination id, once at start-up, a
few per tick; serves <dir>/BrickModels/UserMade/<bucket>/<id>.<ext>.sd0 under
client_path, /<folder>/UserBrickModels and the root (.hkx 404).
- World: UgcManifest answers on the main thread with one indexed query per
request; files not made yet are answered when they are (looked at again
every 5 seconds), and a model in its quiet period is made right away. No
worker threads, HTTP or file reads in the world.
Off by default (ugc_manifest=0): checked in game, the client then downloads
from http://127.0.0.1:80/lwoclient/UserBrickModels/ whatever its boot.cfg says
and logs the player out when it can't connect, so icons need the UGC server on
port 80 of each player's machine. docs/UgcServer.md has the details.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
