Real-Time Collaboration¶
Share a model with a link and work on it together — live cursors, a shared spatial tree, synced edits, and a presence roster. No accounts: access is carried entirely by the share link.
How it works in one line
The model lives in a CRDT room (IFCX-native). The owner seeds it from their open model; everyone else joins by link and the viewer reconstructs the model from the room — so a recipient needs no file, just the link.
Enabling collaboration¶
Collaboration ships behind a flag so it stays out of the way until you want it.
| How | What |
|---|---|
| Build env | Set VITE_COLLAB_ENABLED=true (and a server URL — see below) when building/serving the viewer. |
| Per-browser (dev) | In the browser console: localStorage.setItem('ifc-lite:collab:enabled', 'true'), then reload. localStorage.setItem('ifc-lite:collab:server-url', 'ws://127.0.0.1:1234') likewise points this browser at a relay without a rebuild (an empty string forces local-only). |
When enabled, a Share button appears in the toolbar (it's active once a model is loaded). To sync across machines you also need a collaboration server; without one the feature runs local-only (one browser, multiple tabs) — handy for trying it out.
Sharing a model (owner)¶
- Load a model.
- Click Share in the toolbar.
-
Choose what anyone with the link can do:
Access Can… View See the model, the spatial tree, properties, and other people's cursors. Comment …also add issues and markups. Edit …also change properties and geometry. -
Click Copy and send the link. It looks like
https://…/?room=<id>&t=<token>and expires after 7 days.
Opening the dialog puts you in the room as admin and starts sharing your model into it. You can re-copy a link at any access level, and you stay admin for the room.
Sharing several models¶
With more than one model loaded, the dialog first asks what the room should carry, and creates the room only when you press Create link:
| Scope | The room holds… |
|---|---|
| All N loaded models (default) | Every loaded model, each as its own model. Recipients see the whole workspace and can pick, edit and export each model separately (a second copy of a file is listed as "name (2)"). N counts the models that can be shared: a GLB, a point cloud or a model still loading has nothing to put in a room, and the option says "All 2 of 3 loaded models" when one is left out. |
| Active model only | The model that is active in the hierarchy. The others stay private. |
Each shared model gets its own slot in the room, so two copies of the same
file — same file name, same bytes, same IFC GlobalIds — stay two distinct
models with their own geometry, placement and textures. The scope is fixed once
the room exists; re-opening the dialog shows how many models the room carries.
While several models upload, the progress row names the model it is on
("model 2 of 3"). A recipient exports each room model separately. A shared
STEP model with native authored annotations exports back to .ifc while its
portable source covers the complete room model; other room models export to
.ifcx (merged export is STEP-only). The IFCX file carries the model's own /<GlobalId>
paths, never the room's slot, so it opens in any viewer and diffs against the
other copy's export.
Textured models share their UV coordinates and image pixels with the geometry. Recipients do not need the original IFCZIP or access to its image filenames. Images are shared once per content hash, with each surface retaining its wrap settings. Each decoded image is limited to 16,777,216 pixels total (4096 × 4096), with at most 8192 pixels on either side; an unavailable or oversized image is reported as a sharing failure instead of silently dropping its appearance.
Native PDF-vector IfcAnnotation objects can be created before opening Share.
The share operation materializes pending authored rows automatically; no local
export/reopen step is required. A fresh recipient gets every colored 3D part
under the annotation's one selectable identity, plus its symbolic fills in 2D.
An IFC export from that fresh room reopens with the same annotation identity and
symbolic content.
Both owner and recipient need a viewer version that supports textured room geometry. Older rooms that were shared without texture data cannot recover it from the link: load the original textured IFCZIP and create a new share.
Joining (recipient)¶
Open the share link — that's it, no account needed. The viewer joins the room and reconstructs the model:
- the 3D model renders,
- the HIERARCHY panel and explorer (Spatial / Class / Type) populate,
- clicking an element fills the INSPECTOR with its attributes and properties,
- edits made by others appear live.
Recipients work from the room, not a file
A recipient never downloads the original IFC. The model is rebuilt from the shared room as IFCX, with geometry streamed as content-addressed blobs. This works for both IFC5/IFCX rooms and legacy STEP (IFC2x3/IFC4) rooms.
The room panel¶
While you're in a room, a people button appears in the toolbar (with a live participant count). It opens the Room panel:
- Connection + room id — a live status dot (Live / Connecting / Offline).
- Roster — everyone present: colour dot, name, role badge, and current activity (active / idle / measuring …). You're marked (you).
- Copy invite link — mint and copy a fresh link.
- Leave room — disconnect and return to solo editing.
- Admins additionally get:
- Revoke link — invalidate the last share link you handed out; anyone trying to join with it afterwards is refused.
- Remove (hover a peer) — disconnect a participant; their link is revoked so they can't immediately rejoin.
Roles¶
Roles are baked into the share link and enforced by the server (when one is configured), so a link's holder can't escalate their own access.
| Role | Read | Comment | Edit | Manage |
|---|---|---|---|---|
| Viewer | ✓ | |||
| Commenter | ✓ | ✓ | ||
| Editor | ✓ | ✓ | ✓ | |
| Admin (owner) | ✓ | ✓ | ✓ | ✓ (revoke / remove) |
Privacy & limitations¶
- The share link is the credential — anyone with it gets that role until it expires (7 days) or an admin revokes it.
- A recipient sees the model's structure and properties, but native material and classification cards that need the original file bytes are surfaced as plain property groups instead. Geometry, hierarchy, names, properties, classifications, and materials are all available.
- Per-peer role changes aren't supported — access comes from the link (issue a new link / revoke the old one instead). Admins can remove a peer.
- See also Privacy for the data-handling disclosure.
Running it yourself¶
- Try it locally (no server): enable the flag and open the viewer in two browser tabs — they sync through the browser. Geometry + presence work; this is the quickest way to see it.
- Multi-user across machines: stand up the collaboration server and point the viewer at it. That guide covers signed links, revoke/kick, and deployment.
Georeferencing in shared models¶
A new shared room preserves each model's IfcMapConversion,
IfcProjectedCRS, project length unit, and the coordinate frame used by its
meshes. A recipient can use View → Context → World and inspect the same
georeferencing values as the owner, including when several models are shared.
Georeferencing edits made before creating the link are included. Subsequent
edits and undo/redo update the same room metadata for connected recipients.
Rooms created before this support remain readable. If a room never stored its CRS and coordinate offsets, its owner must create a new share from the original model to restore World context. This metadata belongs to the room's model slots; exporting the root-only IFCX snapshot does not turn it into a complete portable IFC model.