Object Vertex Weight Copy

Some weight edits are per-vertex and boring: you want one vertex to have the exact same weight profile as another one. That's copy-paste, and Object Vertex Weight Copy is the copy half. It takes the weight data of the active vertex and stores it on Blender's clipboard - then its sibling, Object Vertex Weight Paste, can drop that same profile onto other vertices.

This is the finicky, surgical end of weight editing. It's not for sweeping passes; it's for fixing the one vertex that sticks out.

How it works

An auto-generated wrapper around Blender's bpy.ops.object.vertex_weight_copy. There are no parameters - just BPY_OBJ in, and the same object out. What matters is context:

• The active vertex is the source. That's decided by the mesh's edit-mode active selection, not by anything you set on this node.
• "Weight" here means the vertex's weight in the active weight group at that moment.

The natural flow in the graph: select the vertex you want to steal from, make sure the right weight group is active, run Copy. Then later, select the target vertex and run Object Vertex Weight Paste with the same group active.

Because it's a clipboard operation, the copied weight survives across nodes - you can Copy, do other work, then Paste where it matters. Output is the passthrough BPY_OBJ.

Installing it

It's part of the Avatar Graph pack:

cd ComfyUI/custom_nodes
git clone https://github.com/avatechai/avatar-graph-comfyui
cd avatar-graph-comfyui
python -m pip install -r requirements.txt

Restart ComfyUI, or install "Avatar Graph" from ComfyUI Manager. Pack-wide notes: bpy==3.6.0 demands Python 3.10 (the README suggests a dedicated conda env), and bpy is a multi-hundred-MB headless Blender.

Common issues

The usual failure is a missing or wrong active vertex - Copy grabs whatever vertex is active, and if nothing meaningful is active, the clipboard holds garbage or nothing. Pair it deliberately: set up the active vertex before Copy, the target vertex before Paste.

And as with every node here: no BPY_OBJ from an upstream mesh node, no clipboard magic. If you're trying to copy weights onto an image, you've got the wrong pack entirely.