◎Overview

Basic usage of this tool is summarized in the Help dialog.

▼Step 1: Open the Help dialog

Click ［Help］（? icon） at the top right of the screen to open the Help dialog.

The Help dialog provides basic information including how to use the tool.
Refer to it as needed.

◎Merge — Basic Modes

▼Three modes available

• First: Merge to the first selected vertex
• Center: Move to the centroid of the selection
• Last: Merge to the last selected vertex

For details, see “Merge”.

◎UV Behavior

▼Preserve UVs: ON

• Without seams: fully copy UVs, align, then merge (minimizes offsets).
• With seams: delegate to Maya’s native “Preserve UVs” behavior.

▼Preserve UVs: OFF

• With Preserve UVs off: fast processing with no UV coupling.

See “Preserve UVs” for details.

▼Automatic Unpin

• UV Pin/Unpin: automatically toggles pinning when switched ON/OFF.
• Auto Unpin: when ON, merging automatically unpins the merged vertices (UVs).

See “Auto Unpin UVs” for details.

◎Quick Mode Behavior

• When Quick Mode is ON, you can also merge by clicking in the viewport in addition to the Merge button.

See “Quick Mode” for details.

◎Preflight

• On vertex selection, detect if the merge would produce non-manifold/lamina or other error meshes.
  (Configurable as Warn-only or Hard Block.)

▼Warn only
　Use when you prefer to defer cleanup and continue editing.

▼Hard block
　Use when you must prevent creating error meshes.

◎Dangerous Selection Detection

• Treat “Select All”–“Select All-3 vertices” as dangerous; stop in advance with a message.
  (If below the danger threshold, merge is ready.)

• If “Max Vertex Count” or “Max UV Set Count” is exceeded, stop beforehand with a message.
  (Defaults exist for load control; configurable.)
  Note: PolyMate Merge Light (free) lacks this feature and applies fixed caps.

• If vertices from multiple objects are selected, stop in advance with a message.

• If the reference vertex for the merge is deselected, stop in advance with a message.

◎Automatic Rollback

• Preflight and dangerous-selection detection capture errors in advance as much as possible, but to cover rare misses,
  if Maya detects errors such as geometry loss, it automatically Undo-restores to the state just before the merge.

Note: These measures are effective but do not guarantee complete avoidance/detection under all selections and scene structures.

◎Session Hygiene

▼Designed to avoid slowdown, breakage, or unintended actions during long use.

• Reentrancy guard: pause re-execution and watchers during processing to prevent double triggers.
• Job/Callback management: centralized register/unregister; fully released on exit.
• Panel cleanup: detect panel switch/close/rename and unhook immediately.
• Temporary-setting restore: confine changes to the processing scope and revert on completion.
• Safe recovery on error: automatic Undo → keep edit mode → short operation lock to prevent repeated mis-operations.
• Notifications: messages auto-dismiss over time; selection or mode is not changed.
• Cache hygiene: cache only where needed; clear safely on switch/exit.
• Multiple-instance suppression: reuse/bring-to-front the same window to avoid state splits.
• Collision avoidance: separate settings and temp files with unique prefixes to avoid interference.
• No-pollution policy: do not create resident nodes; leave no residue after the session.
• Startup cleanup: detect leftovers (jobs/filters, etc.) from the previous run and remove them first.