Re-dressing after a change
Change the draft, come back to Design, and the city re-dresses itself. This page covers City sync — what fires automatically, what it sends, what it costs, and why the other button called sync does something completely different.
What City sync is
Nothing about a dressed city is baked into the draft. The draft is the structure; the dress is a separate result the cloud produces from it. When you change the structure, the dress that came from the old structure is stale, and City sync is what closes that gap.
City sync is the button with the refresh glyph in the iCity Editor header, in the cluster on the right: Stop, then the sync button and its ▾, then the Draft / Design toggle. Its tooltip reads “Re-dress the city now, from the current draft. The arrow beside it chooses Auto or Manual”.
Close crop of the right-hand end of the iCity Editor header in a project that already has a dressed city, with the engine running: the Stop button, the City sync button showing its refresh glyph, the ▾ beside it, and the DRAFT / DESIGN toggle set to DESIGN.
A re-dress sends your changed city up, runs the frontend lane on it, and brings back outputs.usd and outputs.csv which the addon imports and links onto the city. It uses the theme you already have. It never generates a new one.
Your city is not your .blend. It lives in an engine process you start from the header, and it is saved by the header S button into Documents/iCity 2/<project>. See How iCity fits into Blender.
The automatic path
City sync is set to Auto when you start. Auto means what it says here: the re-dress genuinely fires by itself.
- Switch the header toggle to Draft and change the city — move a road, reshape a lot, change a region's type.
- Switch back to Design.
- About two seconds later the changed objects are exported, uploaded and dressed. The log reads “Syncing the city to the cloud — the … changed since the last dress. Re-dressing with the current theme.”re-dressing-sync-log-line.png
The iCity Logs editor immediately after switching back to DESIGN following a draft edit, scrolled so the “Syncing the city to the cloud — … changed since the last dress. Re-dressing with the current theme.” line is the last one on screen.
/docs-shots/blender/The iCity Logs editor as an automatic re-dress fires. - When the result comes back it is imported and linked automatically. Nothing else to press.
Only the objects that actually changed are sent. The addon keeps a per-object counter and compares each city object against its front-end twin, so a road you nudged goes up with the family the engine rebuilt alongside it, and the rest of the city stays where it is.
On a partial send — which is what a re-dress is, once a dress exists — the front end of the objects being re-baked is removed at the moment they are sent, not when the result lands. The patch of city you edited goes bare for the length of the round trip and then comes back dressed. That is deliberate: it is better than looking at a dress that no longer matches the draft. A full send is the exception; there the old dress stands until its replacement arrives, so you are never left staring at an empty scene.
The 3D viewport during a partial re-dress: one road and the buildings around it stripped back to undressed draft geometry while the rest of the city is still fully dressed. Shoot in the window between the send and the result landing.
Two guards keep Auto quiet. It refuses when the draft has not changed since the last sync, and it will not fire automatically twice inside thirty seconds. Pressing the button yourself bypasses the thirty seconds; it does not bypass the “nothing changed” check.
If you keep editing while a sync is in flight, those edits stay marked as needing a dress and go up with the next one. When a link finishes with work still owed, one more settle is armed on its own.
Doing it by hand
Click the ▾ beside the sync button to open a menu titled City sync with two entries:
The menu titled City sync open under the header ▾, showing both entries — Auto and Manual — with Auto marked as the current choice. Capture the header sync button in the same frame.
In Manual nothing fires on a module switch. Press the sync button whenever you want the dress brought up to date. The button works in Auto too — it is the same single action either way.
The button's colour tells you which state it is in:
- —Green — Auto is on and there is something it could re-dress.
- —White — you set it to Manual.
- —Grey — Auto is on but there is nothing to re-dress, or the last attempt failed.
City sync is not Project sync
Two buttons in this interface wear the same refresh glyph and the same word. They do entirely different things, and only one of them is automatic.
One capture of the whole iCity Editor panel, tall enough to show both the header City sync button with its ▾ at the top right and the footer sync button beside the project name at the bottom left. Mark or crop nothing — the point is that the same glyph appears twice in one panel.
Quitting Blender writes the live city into the active project folder on disk. It does not upload anything. To put your work on Parametra you press the footer sync button and type what you did — see Saving, syncing and versioning.
What a re-dress costs
A re-dress generates nothing. It re-runs the geometry step against the theme already in your project and re-links the assets you already own, which is why it asks you for no prompt and why it is quick.
It also cannot turn into a theme job by accident. City sync refuses to fire at all — by hand or by itself — unless outputs.csv or outputs.usd is in the project folder and assets.json is beside it — that is, unless a dress already exists to re-run.
The addon's own measured figures, taken from completed jobs, put a frontend job at about 3 credits and a fraction of a minute across nineteen runs. A full theme is a different order of thing: roughly 220–275 credits and something close to twenty minutes. Generating new materials and props is what costs; re-dressing with a theme you have is not.
Every cloud job is metered from what it actually consumed and charged after it runs, so a figure here is a measurement rather than a price list. There is no balance check in front of a submit.
What a re-dress replaces
A re-dress replaces the front-end twin of every object the engine regenerated. The addon counts regenerations per object and stamps each twin with the count it was baked from; when the two disagree, that twin is stale and is rebuilt. Objects the engine did not touch keep the dress they have.
An object you have locked is skipped when the engine regenerates it — its mesh is not overwritten. Locking is Lock / Unlock, reachable from Blender's F3 search. A locked object also drops out of procedural editing and shows UNSYNCED in the selection header.
The full rule for hand-edits, moved props and materials you tweaked in the shader editor is stated once, in What survives a re-dress. Read it before you start hand-editing dressed geometry.
Undo does not reach a dress. The linker suspends Blender's global undo while it imports, so Ctrl+Z after a dress will not put the old one back. You re-dress instead.
When nothing happens
A refusal is silent on the automatic path and spoken when you press the button — a click that does nothing has to say why. Look in the iCity Logs editor; the line reads “Nothing to re-dress — …” or “City sync — …”.
The iCity Logs editor right after the City sync button was pressed in a project where nothing is stale, scrolled so the “Nothing to re-dress — the draft has not changed since the last sync” line is the last one on screen.
One case is not a refusal but is worth knowing: after the engine restarts, it cannot compare the draft against a state from before the restart, so the next switch to Design counts as changed and spends one dress. The log names the reason as “no baseline for this engine run”. That is chosen on purpose — shipping a stale city while claiming the two sides are in step would be worse than one extra job.
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