About yuzuWeightEditor

yuzuWeightEditor is a Blender add-on for viewing and editing weights in a spreadsheet-style interface.  

Inspired by Maya's SiWeightEditor, it brings vertex group inspection, numeric editing, copy/paste tools, symmetry workflows, and binding helpers into a single editor window.

Note: The screenshots and GIFs in this README show the Japanese UI, but the released add-on also supports an English UI.

What It Does

• View and edit vertex-group weights in a spreadsheet-style layout
• Switch between selected-only display, full display, and viewport-linked display
• Sync selection with the 3D viewport and highlight selected vertices
• Detect invalid weights
• Round weights, normalize values, and limit the maximum influence count
• Copy and paste by cell, vertex, or object
• Apply weight symmetry workflows
• Delete unused vertex groups and add missing bone vertex groups
• Assist with bone collection visibility, armature display, modifier visibility, and weight display

Requirements

• Blender 4.2 LTS
• Blender 5.0

This add-on does not run purely inside Blender's standard UI. It opens a separate editor window built with PySide6.  

If PySide6 is not installed yet, you can install it from the add-on panel using Install PySide6.

Main UI / Tools

Spreadsheet

• Tabs: Vertex groups are separated into All, Deform, and Other.
• Header: Displays vertex groups. You can right-click to rename a vertex group. Renaming a Deform group also renames the corresponding bone.
• Vertex Group Lock: Click the icon to lock a vertex group.
• Cells: Edit weight values directly here.
• Numeric Input: Right-click a selected cell, or select it and type a number key to start numeric input. When multiple cells are selected, the same value is applied to all of them.
• Copy/Paste Menu: Hold Shift or Ctrl and Right-click to open the copy/paste menu, where you can use VC / VP / MP / CC / CP.

Display Controls

• Show: Display selected vertices only.
• ShowAll: Display all vertices of the selected object.
• Focus: Sync viewport selection and sheet display.
• Highlight: Highlight vertices selected in the sheet inside the 3D viewport.
• View Wt: Keep weight display visible in Edit Mode.

Bone / Modifier Display

• Show Armature in Front
• Show Bone Names
• Toggle POSE / REST
• Toggle Cage Display
• Toggle Edit Mode Display
• Toggle Modifier Display
• Show Bone Collections

Invalid Weight Detection

• Influence: Check how many bones affect a vertex.
• Under Wt: Check for insufficient total weight.
• Over Wt: Check for excessive total weight.
• Show Bad: Show only problematic vertices.

Spreadsheet Editing / Bone Collection

• Sheet Update Lock: Lock updates to the displayed vertices in the sheet.
• Force Refresh: Refresh the sheet manually. This is mainly useful while update lock is enabled.
• Clear: Clear the current sheet display.
• Select: Reflect the current sheet selection in the viewport. Hold Shift to add to the current vertex selection.
• Bone Collection Display: Adjust bone collection visibility directly from the editor.

Weight Processing

• Display Digits: Set how many decimal places are shown.
• Round: Round weights to the chosen number of decimal places using the spin box.
• Limit Inf: Limit the number of influences. Set the limit in the spin box. A value of 0 means unlimited. If no cells are selected, the operation targets the entire sheet.

Copy / Paste Tools

• VC / VP: Copy and paste on a per-vertex basis. Vertex-group locks and cell locks are ignored when pasting.
• MP: Mirror-paste the contents of VC based on the symmetry naming dictionary.

• CC / CP: Copy and paste on a per-cell basis. Locked vertex groups and locked cells are skipped when pasting.

• WC / WP: Transfer weights between selected mesh objects.

• WS: Apply weight symmetry. Right Click opens the symmetry naming dictionary.

Symmetry Naming Dictionary

Vertex Groups / Binding Tools

• Delete Unused Vertex Groups: Deletes vertex groups whose weight is 0 on every vertex.
• Add Missing Vertex Groups: Adds missing vertex groups in one click when a related armature has bones but the corresponding vertex groups do not exist.
• Bind: Available when one armature and one or more mesh objects are selected.
• Unbind: Removes the armature modifier from mesh objects and also clears armature parenting if it exists.

Weight Hammer / Weight Smooth

This is an experimental feature.

• Weight Hammer: Adjusts the weights of vertices selected in the sheet to better match surrounding weights. Useful when only a few vertices have incorrect weights.
• Weight Smooth: Smooths the weights of vertices selected in the sheet. Right Click opens its settings.

Cell Locks

• Lock Wt: Lock selected cells so they cannot be edited in the editor.
• Unlock Wt: Unlock selected cells.
• Clear Locks: Clear cell locks for the selected object.

Numeric Editing / Normalize

• Absolute Input: Replace cell values with the slider value.
• Additive Input: Add or subtract the slider value from the current cell values.
• Percentage Additive Input: Add a percentage of the current value. For example, if the weight is 0.5 and the slider is 0.5, then 0.25 is added, resulting in 0.75.
• Normalize: Auto-normalize toggle. When enabled, edits in the editor are automatically normalized. Right Click forces normalization for the target range. If no cells are selected, it targets the entire sheet.

Preset Buttons

• 0.0~1.0: Quickly enter commonly used values. Click to replace, Shift to add, and Ctrl to subtract.

Active Sort / Vertex Group Search

• Active Sort: When multiple objects are selected, show the active object at the top of the sheet.
• Vertex Group Search: Search by vertex group name. When Filter is enabled and some vertex groups are hidden, you can toggle their visibility. Clicking a vertex group name jumps to that group's position in the sheet.

Vertex Group Sort

• Set the display order of vertex-group columns. Deform and Other can each be configured separately.
• Hierarchy (Deform): Sort deform vertex groups by hierarchy.
• Alphabetical: Sort vertex groups alphabetically.
• List: Sort vertex groups according to Blender's list order.

Reordering Vertex Groups

You can reorder vertex groups only when vertex-group sorting is set to List. The result is also reflected back into Blender. Middle-click a header to select it, then middle-drag to reorder it.

Bottom UI

• Toggle Mirror Editing: Toggle mirror editing in Edit Mode. When enabled, vertices on the opposite side of the selected vertices are also shown, and editing one side affects the other side.
• 0-1 / 0-100 Display Toggle: Switch between displaying weights in the 0-1.0 range or the 0-100 range.
• Col W: Adjust column width.
• Zero-Weight Brightness: Adjust the brightness of 0 weights.

Preferences

These settings are configured in Blender's preferences.

• Language Settings: When set to automatic, some editor text such as descriptions and error messages follows Blender's language setting. You can also switch it manually.
• Realtime Weight Apply: Controls whether slider-based weight edits are applied in real time. Disable it if the editor feels heavy.
• Highlight Settings: Settings for viewport highlights.
• Highlight Color: Set the highlight color.
• Highlight Size: Set the highlight size.
• Highlight Shape: Set the highlight shape.
• Highlight Limit: Set the maximum number of highlight markers shown.