Release Notes 1.2.1

1.2.1f3 (2026-07-03)

Improvements

General

• Added options to determine which tool becomes active upon selecting an object. (Configurable via Preference > UModelerX > Editable Mesh > Tool On Object Enter)
  • Last Used Tool Per Object: Activates the tool that was last used for each individual object.
  • Keep Current Tool: Maintains the currently active tool even when switching to another object.
  • Object Tool: Force-switches to the Object Tool / Object Mode whenever entering an object's edit mode.

Modeling Mode

• Modifiers: Added Preview Overlay and Preview XRay options. These options allow you to view the edge overlays of modified meshes or display them in X-Ray form.

Rigging Mode

• Bone Tree: Added help tooltips/documentation inside Rigging Mode.
• Bone Tree: Added dedicated buttons to easily add and delete bones.

Bug Fixes

General

• Fixed a critical Unity build failure that occurred when prefab assets were located inside Resources folders. To resolve this, the internal link connection between Unity assets and the UModeler X editor-only SaveData has been decoupled.
• Added 'Assets > Export Package with UModelerX SaveData' menu: Due to the data decoupling mentioned above, a new menu has been added to let users safely export packages along with their corresponding Save Data.
• Fixed an issue where the Mesh Optimization Save feature did not apply to rigged meshes.

Modeling Mode

• Fixed an issue where the gizmo position would become locked when double-clicking the rotation or scale gizmo handles.
• Modifiers: Fixed stability issues and errors that triggered during object activation/deactivation or during modifier use.
• Mirror Modifier: Fixed a bug where the gizmo would not move while in Object Mode.

Rigging Mode

• Bone Tree: Fixed an error that occurred when attempting to delete a currently selected bone itself.

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1.2.1f2 (2026-06-24)

Bug Fixes

Modeling Mode

• Modifiers: Fixed a bug where modifiers would detach or disable upon saving the scene.
• Rectangle Tool: Fixed a bug where drawing a rectangle that split into two or more parts on an existing face caused them to merge unintentionally.
• Radial Array & Linear Array Tool: Fixed issues where Boolean operations were not applied correctly.
• Inset Tool: Fixed a bug where Boolean operations failed when the Bridge option was toggled from ON to OFF during use.

Painting 3D Mode

• Sticker Layer: Fixed an issue where the layer was not functioning properly.
• Fill Layer: Fixed an issue where the wrong properties were displayed.
• Rect Fill Tool: Fixed an issue where pressing the Enter key to complete the action in polygonal lasso fill mode did not work as expected.

UV Editor

• Modified behavior so that the material is automatically selected when only one material is present.

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1.2.1f1 (2026-06-23)

Bug Fixes

General

• Added support for Unity 6.5.
• Fixed an issue where deactivated objects were excluded when migrating from UModeler Classic.
• Fixed an issue during prefab editing where UModeler X mesh updates were not applied if auto-save was enabled, modifications were made to UModeler and GameObjects, and the user exited within the Auto Save Sync Delay timeframe.

Modeling Mode

• Fixed an issue where side faces became corrupted during 2D Boolean operations.
• Radial Array Tool / Linear Array Tool: Fixed an issue where flat surfaces that should not be affected by boolean operations were incorrectly merged.

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1.2.1 (2026-06-18)

New Features

General

• Added a feature to load SaveData specified in the Project tab into the current scene.

Modeling Mode

• General
  • Added Mesh Optimization Save. This feature deletes empty data inserted during editing to improve speed.
• Element Tools
  • Added Element Hide feature. This allows you to temporarily hide specified elements while editing. They are restored when you exit the editor.
  • Vertex Tool: Added a Vertex Group feature.

UV Editor

• Added a UV Element Hide feature. This is linked with the Hide feature in Modeling Mode.

Painting Mode

• General
  • Painting information used in UModeler X is now separated into material, texture, and paintData files, and saved in the Assets/UModelerXData/ folder path. Projects from previous versions will be automatically migrated when opening a scene. For Prefabs, you can migrate them directly by opening them or migrate them all at once using the Tools > UModelerX > Scene Data > Migrate Painting Data on Prefab menu.
  • After painting in the Painting3D Editor, clicking the Apply button immediately applies the painting to the object's texture. Alternatively, you can enable Auto Apply to automatically save when exiting Painting Mode.
• 3D Gradient Tool: You can now apply a gradient color based on 3D coordinates in the Scene. There are three options: Mouse, Axis, and CurveMesh.
• Stroke: Added a Stroke effect. You can set a stroke with a certain thickness towards the inside or outside.
• Level: Added a Level effect. You can adjust colors to be brighter or darker.
• Color Palette: Quickly select colors to use. Press Shift+Alt+Right-Click in the Scene to display the UI.
• Grid: You can display a grid in the Painting 2D window to show exact sizes. This can be configured in the View > Grid menu at the top, and toggled on/off using the button in the top right.
• Snap: You can precisely control the cursor position in the Painting 2D window. Two options, Grid and UV Vertex, are available and can be configured using the button in the top right.
• Color Range Selection: You can set a selection area based on a color range on a layer in the Painting 2D window. When selecting a mask layer, it targets the mask layer texture.
• Reverse Brush Opacity: Added a feature to invert the brush's Opacity value. Use Shift+X to toggle.

MultiObjectEditor

• MultiObjectElement Tools
  • Added the ability to move elements while multiple UModelerXEditableMesh objects are selected.
  • The same UV movement features can also be used in the UV Editor.

PicoBerry

• Object-based Generation: Clicking the button at the top now creates a PicoBerry object. Place it in the scene to quickly generate models. You can open the existing library using the button in the top right.
• Team Workspace: An asset library shared with team members.
• Collections: You can group desired assets into a single collection.
• Rigging & Animation: You can import animation models generated on the web.

Improvements

General

• The save locations for UModeler X related data have been changed.
  • A new Save Data section has been added under Preferences > UModelerX.
    • Save Data Folder: The folder to save UModeler edit data.
    • Mesh Folder (Scene): The folder to save meshes placed in the scene.
    • Prefab Mesh Folder: The folder to save meshes contained in prefabs.
    • Auto Save Sync Delay: When auto-save is enabled for Prefabs, this delays saving until editing is finished to avoid writing large amounts of data to files too frequently.
    • Mark Saved Mesh Read-Only: An option that turns off "Readable" when saving. Turning this on uploads the mesh to GPU RAM, improving speed.
• The Inspector now displays in both locations.
• Modified the preference window to open based on the currently selected editor.
• For X-Ray Mode, you can now specify a separate texture (Preferences > UModelerX > Modeling > Material > X-Ray Texture).

Modeling Mode

• Quadify Tool: Added a selection feature where double-clicking selects the area between the last selected face and the double-clicked face.
• Deform Group: Pen pressure is now applied when using a pen tablet.

UV Editor

• Added a feature to view automatically assigned UVs for un-unwrapped faces.
• Added zoom functionality using Alt + Left/Right Mouse Drag.
• The current zoom level is now displayed in the top left corner.
• You can adjust the maximum/minimum zoom limits for the UV editor in Preferences.

Painting Mode

• Layer Merge: Added layer merging capabilities. You can merge with all layers, selected layers, visible layers, or the layer below.
• Improvements when using Move and Free Transform tools:
  • Free Transform: Improved to allow adjustments via numerical input or arrow keys.
• Texture Asset: Improved to easily add texture assets to the Painting2D Window via drag-and-drop.
• Layer Blend Mode: Improved so layer blend modes can be adjusted using the mouse wheel.

PicoBerry

• Improved the refreshing of the asset list in the Text and Image tabs.
• Improved the properties displayed during 3D/2D generation to match the web version.

Bug Fixes

General

• Fixed an issue where the activation conditions for the UModelerize/UModelerize Hierarchically menus were incorrect.
• Fixed an issue where objects were created outside the prefab when using object creation features in the Prefab Stage.
• Fixed a bug where the undo stack for tool changes executed within a prefab was not cleared upon exiting the prefab.
• Modified duplicated objects to inherit the tool state of the original object.
• Fixed a bug that occurred when selecting a scene (or similar) and right-clicking Assets / UModelerX.
• Fixed a bug that occurred in multiple inspectors when undoing after UModelerize.

Modeling Mode

• Modifier
  • Mirror Modifier: Fixed issues that occurred when entering Play mode, etc.
• Fixed issues with features that use Boolean2D (Drawing Group, Inset Tool, Radial Array, Linear Array).
• Shape Tools: Fixed a bug where the overlay was not displayed upon initially entering the tool.
• Inset Tool
  • Fixed a bug where Boolean2D did not work properly when selecting multiple faces with Bridge turned off.
  • Fixed a bug that occurred in the Group option when there were faces that only touched at the vertices.
• Bevel Tool: Fixed a bug where UVs broke on adjacent unwrapped face holes during a bevel.
• UVParam Tool: Fixed issues that occurred during Undo/Redo while using this tool.

Rigging Mode

• Fixed an issue that occurred when undoing a Remap operation executed due to a skeleton change.
• Reset Pose Tool: Fixed an issue where resetting the pose resulted in an incorrect pose.

Painting Mode

• Painting2D
  • Fixed an issue where the aspect ratio was not maintained when changing the resolution after locking it.
  • Fixed an issue where PaintData was not saved when pressing Ctrl+S.
• Fixed an issue where paint data disappeared after modifying the mesh structure.

MultiObjectEditor

• Fixed a bug where other objects could not be selected with the mouse while in the Multi-Object Editor state.
• Fixed a bug where the UV Focus feature did not work.

UV Editor

• Fixed selection bugs and an issue where build updates were not immediately applied when modifying a non-zero UV channel in the UV Editor's UV Channel.
• Multi Channel UV: Fixed an issue where the mesh was not immediately updated when adding or deleting a channel.
• Weld And Break: Fixed an issue where maps would occasionally disappear when using this tool.
• Auto Layout Tool
  • Fixed an error that occurred when performing auto layout on already unwrapped faces.
  • Fixed an issue where UVSeam was not applied.
  • Fixed an issue with the unwrap order when applying auto layout.