Object Set Visible Volume Scatter

Of the six ray-visibility flags in Avatar Graph, Object Set Visible Volume Scatter is the one tied to the most invisible thing in the scene: the air itself. It wraps Blender's "Ray Visibility" toggle for volume-scatter rays - the paths that handle fog, smoke, and atmospheric scattering. For most avatar work it'll never matter. When your scene has atmosphere, it's the flag that decides whether an object is visible through the fog or gets swallowed by it.

What it actually does

Volume scattering is how Cycles renders volumetric effects - fog, haze, smoke, god rays. A volume-scatter ray is a ray that bounces through that volume, which is what makes the fog visible in the first place and what lets you see objects through it. visible_volume_scatter controls whether a given object can be struck by those rays. Default true means it participates normally: the object appears through the fog and interacts with the scattering. Set it false and the object becomes invisible to volume paths - it stops appearing through the haze, while the camera, diffuse, glossy, and shadow paths still see it.

Why would you want that? In avatar work, mostly for compositing discipline. Say your character stands in atmospheric haze but you want a clean, fog-free read of the face for the final composite - or the reverse: you have a duplicate object that keeps catching the scatter and glowing when it shouldn't. Disabling volume-scatter visibility on specific objects lets you keep the atmosphere for the scene without letting it corrupt the elements that need to stay crisp. It defaults to true, and it's the kind of knob you reach for when "there's something wrong with how the fog treats my character" is your exact problem.

The inputs and outputs that matter

• BPY_OBJ - the object whose volume-scatter visibility you're setting.
• value - boolean, default true. false removes the object from volume-scatter paths.

Output is the same BPY_OBJ, handed on to the next node.

How to install it

Part of the Avatar Graph pack - ComfyUI Manager, search "Avatar Graph", or:

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

restart ComfyUI. Pack-wide snag: bpy==3.6.0 only ships wheels for Python 3.10.x, so install fails on modern Python. python=3.10 conda env on Linux/macOS, Avatech's prebuilt Python-3.10 ComfyUI zip on Windows.

Gotchas

If your scene has no volume material, this flag does nothing visible - no fog, no effect, no surprise. And don't confuse it with hiding the object from the camera; turning this off only affects the volumetric path, so the character still renders normally in clear air. Given how render-dependent volume effects are, verify in the exported .glb/.gltf rather than Avatar Graph's real-time preview.