Installation:

Open up Blender and go to Edit > Preferences > Add-ons, click on install then browse to the zip file and click on Install Add-on from File….

Make sure the addon is enabled in the Add-ons panel.

Install only one version, if you attempt to enable multiple versions at the same time, it will cause problems. If you have done this and cannot install: delete all versions of the RizomUV Bridge from your Blender addons, then install the latest version.

Compatibility

• 'RizomUV Bridge - Ultimate Edition' is compatible with Blender 3.3+, Rizom 2022.2+, Windows, MacOS.
• Legacy versions are available for earlier versions of Blender/Rizom.

The addon works by using the RizomUVLink which is a module provided by Rizom-Lab, this allows direct communication with RizomUV, it has the following requirements:

• Windows only
• Rizom 2023+

The addon will automatically detect if you are able to use the RizomUVLink based on your selected Rizom version and operating system, If you are not on a compatible system the RizomUVLink will be disabled and the addon will default to the backup method which doesn't require the link.

The backup methods for MacOS and older Rizom versions can handle UV export/import but lacks the preset scripts and remote control options that the RizomUVLink enables.

Usage:

The addon UI can be found on the sidebar of the 3D Viewport under a tab called RizomUV, the default hotkey to show the sidebar is N. Please note that the RizomUV tab will only appear when you are in object mode.

Using the addon is very simple. Enter object mode and select the objects you wish to export to Rizom then click the Export button, Rizom will open with your objects already loaded. If you selected an autoseams script it will be applied to the active UV map. The Rizom settings will also be changed to match how you set them in the bridge UI.

Once you are done creating your UV maps save your file with CTRL+S, then return to Blender. Click the Import button and your UV maps will be transferred to your objects. The bridge uses the names of the objects and UV maps to determine where to transfer the UVs so it is important that you do not rename them before importing.

Every element of the addon UI has a tooltip so if you don’t know what something does just hover your mouse cursor over it.

Changelog - Ultimate Edition

1.0 — 22nd May 2024

New

• All in one support for Blender 3.3+, Rizom 2022+, Windows, MacOS.
• Optional toggle of RizomUVLink which is automatically disabled on unsupported installations.
• Option to export seams defined in Blender to RizomUV. (RizomUVLink only)
• Option to export texture file and automatically set correct shading. (RizomUVLink only)

Fixes

• Moved data directory to user AppData for Windows, this should allow the addon to function on Windows Store installations of Blender without any additional user configuration.
• Fixed bug with incorrect management of Machin3 Tools focus mode when exporting files.
• Fixed transforms not exporting correctly.

1.0.1 — 26th May 2024

Fixes

• "Apply All To All UVMaps" and "Reset UVs" causes error when used together.

1.0.2 — 13th June 2024

Fixes

• Export not working on MacOS.

1.0.3 — 22nd June 2024

Fixes

• Update bundled RizomUVLink version to latest.

1.0.4 — 6th August 2024

Fixes

• Fixed encoding error with some system languages.
• Switched to more reliable method of checking for RizomUV connection on MacOS.

1.0.5 — 19th August 2024

Fixes

• Fixed problem with Machin3 Tools focus mode being undone upon import.

1.1.0 — 6th September 2024

New

• Replaced "Validate UVSets" with "Edit Names", less destructive and can also be used as more of a utility tool to rename UV Maps.
• Added support for USD file format.

Fixes

• Moved data directory to Documents so that Windows Store installations don't have blocked write permissions.

1.1.1 — 29th September 2024

Fixes

• Fix transformations being messed up under some child/parent hierarchies. (Fixes speedtree exported meshes)

1.1.2 — 1st October 2024

Fixes

• Fixed some parent/child hierarchies not keeping transformations.
• Fix USD export for Blender 4.2 (disable rename UV Maps).

1.1.3 — 13th November 2024

New

• RizomUV metadata exported when file is saved, can be reloaded in Rizom using the "Load" operator (export will overwrite).

1.2.0 — 24th November 2024

New

• USD format can now transfer RizomUV attributes such as groups and pins. These will automatically be imported to Blender and saved on your objects. The objects can then be re-exported to RizomUV, and the attributes will persist.

Fixes

• Fixed problems with USD format import caused by Blender USD import renaming imported objects based on mesh data name. The mesh data is now renamed inside the USD file itself. Actual data in Blender is not affected; this is only visible in the file itself and in RizomUV.

1.3.0 — 11th February 2025

New

• Preference setting to modify the object export orientation.
• Preference setting to move the addon UI between the side panel and the header panel.
• Preference setting to toggle RizomUV auto welding behavior.

Fixes

• Compatibility with Blender 4.4.

1.3.2 — 26th February 2025

Fixes

• Data directory not being set up correctly on macOS.
• Use Seams export option error.
• Export texture option missing.

1.3.3 — 28th March 2025

Changes

• Disabling the Save USD properties option will prevent existing properties being exported back to Rizom.
• Increased the timeout duration when waiting for RizomUV to load, this will prevent errors if it takes longer than 10 seconds.

1.3.4 — 17th April 2025

Changes

• Add confirmation popup for 'Close Rizom' button to prevent accidentally closing Rizom.

Fixes

• Fix exclude clones not working with FBX or OBJ format.

2.0.0 — 11th August 2025

Breaking Changes

• Updated to the new extension format introduced with Blender 4.2, this means version 2.0 is not compatible with older versions of Blender.
• Removed remote Rizom actions. They existed because in older versions of Rizom you couldn't save settings, this is no longer the case so I don't believe they serve a purpose anymore and it removes a significant maintenance burden. If any are crucial for your workflow, please let me know and I will see about adding them back when I have time.

Added

• Connection timeout property, allows the user to set the maximum time Blender will wait for RizomUV before cancelling the operation.

Fixed

• Disabled "Bake Animation" in FBX export, this was causing export to fail for an unknown reason on some meshes.
• Fix a possible crash when saving Rizom attributes to the Blender scene using USD format.

Improved

• Made compatible with upcoming Blender 5.0 release.
• Removed some redundant labels from the UI to make it more compact.
• Moved MacOS addon data out of the addon folder into the documents folder, Windows already does this.
• Added more detailed logging with an option to toggle it, should make debugging easier.
• Improved error handling throughout the addon, more error messages and should now always gracefully handle failures/cleanup.

Known Issues

• Changing the dock location in preferences now requires a restart of Blender to take effect. This is because of an upcoming Blender API change which breaks the functionality I relied on. I intend to restore the original behaviour in a future release once Blender fixes this issue. https://projects.blender.org/blender/blender/issues/123232
• Due to the same issue it is no longer possible for me to automatically handle RizomUVLink availability based on the RizomUV path. This shouldn't cause any problems during use as the addon will just fall back to using a legacy connection at runtime if RizomUVLink cannot be found.

2.0.3 — 17th August 2025

Fixed

• Fixed OBJ export/import.
• Fixed FBX import on Blender versions < 4.5.

Improved

• Rizom automatically saves when clicking import.

3.0.1 — 13th October 2025

Fixed

• Fixed object parent/child hierarchies being flattened upon export.

3.0.2 — 14th October 2025

Fixed

• Fixed objects with non-mesh hierarchies, eg bones, being unparented.

3.0.3 — 28th October 2025

Fixed

• Possible error when importing objects with a non-mesh object in the Blender scene.

3.0.4 — 23rd November 2025

Fixed

• Fixed a cause of infinite session locking on legacy Rizom/Blender connection method.

3.0.5 — 5th December 2025

Improved

• Bundling updated RizomUVLink module with the addon to maintain compatibility with Rizom 2023 and newer Blender versions. The version installed with RizomUV is outdated.

3.1.0 — 7th December 2025

Added

• Option to export background image to RizomUV, only works with RizomUVLink connections.

3.1.2 — 5th February 2026

Fixed

• Fixed exclude clones export not working correctly.

3.1.3 — 19th February 2026

Fixed

• Fixed edge case where non-mesh object selection would cause an error.

3.2.0 — 12th March 2026

Fixed

• Fixed UV map dropdown not updating active UV map.
• Fixed applying subdivision corrupting UV seams.

3.3.0 — 2nd April 2026

Added

• Granular texture display options for RizomUV: background texture, UV island texture, and mesh texture toggles.
• Warning dialog when exporting objects with unapplied scale.

Fixed

• Fixed apply modifiers affecting all scene objects instead of only the ones being exported.
• Fixed FBX export settings conflicting with pre-export modifier application.
• Fixed RizomUV file suffix causing import to fail.

Changed

• Texture export is now behind an explicit toggle instead of being automatic whenever a texture path is set.
• Updated bundled RizomUVLink library to the latest version.

3.3.1 — 15th April 2026

Added

• Empty object support for preserving parent-child hierarchy through the RizomUV roundtrip.

Fixed

• Fixed export texture option showing when LiveLink is not active.

Changed

• Texture settings are now displayed in a separate panel section for clarity.

3.3.3 — 15th April 2026

Fixed

• Fixed RizomUV error when selecting UV maps for empty objects.
• Fixed export name validation not checking empty object names.

3.4.0 — 4th July 2026

Changed

• RizomUVLink is now bundled and installed as a Blender extension wheel dependency instead of being loaded from a manually bundled library folder, improving compatibility with newer Blender/Python versions.
• "Create Missing UV Maps" import option is now enabled by default.

Fixed

• Fixed a crash when unwrapping a UV map that doesn't yet exist on the Blender object.
• Fixed UV unwrap not reliably selecting the correct geometry before unwrapping.

3.4.1 — 5th August 2026

Fixed

• Fixed RizomUV hanging on the first export of a session when using RizomUVLink, most often seen after restarting your computer.
• The cached connection port is now cleared when RizomUV is closed from the addon, so a dead port is never carried over into the next session.
• Fixed the connection retry loop running without pause while waiting for RizomUV to start, which made Blender unresponsive for longer than necessary.

3.4.2 — 5th August 2026

Fixed

• Fixed "Reset UVs" corrupting the active UV map name when it contained a dot, which could reset the wrong UV map in RizomUV instead of the intended one.
• Fixed UV maps not being fully removed from imported objects when "Delete Unmatched UV Maps" was enabled.
• Fixed imported objects being permanently left with generated placeholder names if an error occurred early in the import process.
• "Reveal Hidden" now actually unhides objects and collections before importing, and leaves them visible afterwards; previously the option had no effect.
• Fixed import failing silently after retrying instead of reporting an error.
• Fixed USD export rejecting valid object names containing underscores.
• Fixed RizomUV version comparisons treating some older versions as meeting a newer minimum requirement.
• Fixed RizomUV USD attributes with falsy values (such as 0, False, or empty text) being dropped on export.
• Fixed RizomUV USD attributes accumulating duplicates across repeated imports.
• Fixed a placeholder value reaching RizomUV as a literal UV map name when no object or UV map was selected.
• Fixed potential crashes when exporting or importing objects that have no UV maps.

Changed

• Enabling/disabling the addon now correctly restores the header popover based on your dock location setting.