Object Set Lightgroup

ObjectSet Lightgroup assigns a Blender object to a light group - Cycles' way of letting you organize lights into named buckets so you can control which lights affect which objects, or separate them into render passes for compositing. If you've ever needed "this light should only light the face, not the background," light groups are the feature, and this node is how you'd tag the object.

The property it sets is lightgroup, a plain string, and the default is empty - meaning no group, standard behavior. Set it to a group name (say key_light) and the object becomes associated with that group, so you can link lights to it and pull its contribution out separately in the compositor. It's a Cycles 3.5+ thing, so it only means anything when you're actually rendering with Cycles and using light-link or light-group passes.

Now the honest part: for Avatar Graph's typical workflow - turn an image into a rigged mesh, export a .GLB, animate it - light groups are deep-end features you almost certainly don't need. The demo templates don't use them. This node is one of the auto-generated setters the pack exposes because it dumps every Blender object property, and the string setters like this one are trivial for it to include. If you're not doing studio-style compositing with light-link passes, leave it empty and don't think twice.

How it works

Standard ObjectSet_* mechanics: BPY_OBJ in, a string value (default empty), a setattr on the Blender object, same object out for the next node in the chain.

Inputs that matter:

• BPY_OBJ - the object to tag with a light group
• value - string, the group name; empty default means no group

Installing Avatar Graph

This node ships with the whole pack:

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

Or ComfyUI Manager → Install Custom Nodes → search Avatar Graph → restart. Pack gotchas as always: bpy==3.6.0 needs Python 3.10 (bundled 3.10 environment on Windows via the README; conda on macOS/Linux), and first launch downloads the SAM ViT-H model plus the mediapipe face/pose landmarkers.

Common issues

A light group name does nothing by itself - you also have to set up the lights and the light-link/light-group pass in the Blender scene for it to have an effect, and this pack doesn't expose those bits as nodes. So a group name you type here won't visibly do anything unless the rest of the lighting setup exists. If you typed a group name and "nothing happened," that's expected, not a bug. And remember the scene resets every run - the assignment has to come from the graph each time.