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Installation

Rhea ships as two files, and you install exactly one of them. Which one depends on your Blender version, because Blender changed how add-ons are packaged in 4.2.

Which file do I install?

Pick one

rhea-1.0.0.zip4.2 – 5.x: The extension build. Install through Edit → Preferences → Get Extensions → Install from Disk. This is the file almost everyone wants.
rhea-legacy-1.0.0.zip4.0 – 4.1: The legacy add-on build. Install through Edit → Preferences → Add-ons → Install. Same features, older packaging.

Do not install both

The two files contain the same add-on under the same name. Installing both leaves Blender with two copies of every operator and panel. Uninstall one before installing the other.

Installing on Blender 4.2 and later

01
Open Preferences
Edit → Preferences, then choose the Get Extensions tab.
02
Install from disk
Click the dropdown arrow at the top right of the panel and choose Install from Disk. Select rhea-1.0.0.zip.
03
Confirm it is enabled
Rhea appears in the list with its checkbox ticked. If it is not ticked, tick it.
04
Find the panel
In the 3D viewport press N to open the sidebar. There is now a Rhea tab down the right-hand edge.

Installing on Blender 4.0 and 4.1

01
Open Preferences
Edit → Preferences, then the Add-ons tab.
02
Install
Click Install… and select rhea-legacy-1.0.0.zip. Do not unzip it first — Blender wants the zip.
03
Enable it
The list filters to the newly installed add-on. Tick its checkbox. Unlike extensions, legacy add-ons are installed disabled.
04
Save preferences
Blender 4.0 and 4.1 do not always auto-save preferences. Use the hamburger menu at the bottom left of the Preferences window and choose Save Preferences so Rhea is still enabled next launch.

Updating

Install the new zip over the old one. Blender replaces the package in place and your preferences survive. Scenes saved with an older Rhea keep working: the effect stack stores its parameters on the object, so a newer version reads them and rebuilds the same result.

Restart after updating

Blender keeps Python modules loaded for the life of the session. After installing over an existing copy, restart Blender before reporting anything odd — a half-reloaded package produces errors that vanish on restart.

Preferences worth knowing about

Rhea adds its own preferences page under the add-on entry. The defaults are chosen to be safe rather than fast, so it is worth a look.

Vertex budgetdefault 4,000,000: The ceiling on generated geometry. Rhea refuses rather than hangs when a setting would produce more than this. Raise it if you have the RAM and know what you are asking for.
Auto-rebuilddefault off: Whether baked stack items rebuild automatically when their source geometry changes. Live effects always update; this is only for the applied kind.
Live previewdefault on: Whether dragging a slider rebuilds at reduced quality for responsiveness, then at full quality on release.
Preview decimationdefault 200 faces: How far components are simplified during a live drag. Lower is more responsive and less representative.
Accent colour: The teal used for active states and overlays. Override it if it clashes with your theme.
Preset directory: Where your own saved presets are written. Point several machines at a synced folder to share a library.

Verifying the install

The fastest check that everything registered correctly takes about ten seconds:

Open the Rhea tab in the sidebar.
Expand Library and click any base shape. An object appears.
Expand Effects and click any effect thumbnail, then Apply recipe. The shape changes.

If all three happen with nothing in the console, the install is sound. If any of them do not, go to Troubleshooting.

Uninstalling

Remove the add-on from Preferences the same way you installed it. Nothing is left behind in your scenes that would break them: an applied result is plain mesh data, and a live result becomes an inert Geometry Nodes modifier that you can delete. No files are written outside the add-on directory except presets and fabrication exports you asked for explicitly.