Regional Split Regions (Nukun)

If you're already an A8R8 Attention Couple user, you know its particular brand of regional conditioning - and you know that feeding it correctly shaped regions is half the battle. This node is the bridge: it builds simple 2- or 3-way split masks and returns them in the ATTENTION_COUPLE_REGION format A8R8 expects, ready to connect directly. No geometry conversion, no format fiddling. You draw splits, A8R8 gets regions.

The context: A8R8 is a model-patching regional technique, different from the pack's core-metadata "Native" approach. Where Native Regional Split Conditioning uses ComfyUI's built-in conditioning metadata (portable, no patching), A8R8 patches attention itself for stronger region separation. Both have their fans; this node sits firmly on the A8R8 side, and it needs no runtime A8R8 dependency of its own - it just emits the data format. You provide the A8R8 nodes.

How it works

Feed in positive_1, positive_2 (and positive_3 for three regions), set region_count, orientation (horizontal = left/right split, vertical = top/bottom), and width/height. split_1 (0.5) and split_2 (0.67) place the boundaries, weight_1..3 set each region's attention weight. The regions output plugs straight into A8R8's Attention Couple input, and mask_1..3 give you previews. At region_count 2, positive_3, split_2, and weight_3 are ignored and mask_3 comes back empty.

One thing worth knowing: there's no overlap control here, unlike the native split node - A8R8 handles region boundaries its own way, so you don't need a soft-edge knob.

The wiring

The typical graph: text encoders → this node's positive_1..3 → regions → A8R8 Attention Couple → sampler. If you don't already have A8R8 installed, that's your extra step - search for the A8R8 pack in ComfyUI Manager. The node itself doesn't depend on it, so your workflow can also just preview the masks and decide you actually wanted the native path after all.

Installing it

Same pack, same drill:

cd ComfyUI/custom_nodes
git clone https://github.com/OnekoSL/Nukun_ComfyUI_Nodes.git

Restart ComfyUI, or install via Manager (search "Nukun"). The A8R8 nodes are a separate install if you don't have them.

Common issues

The usual orientation trap applies - horizontal is a vertical boundary creating left/right regions. Beyond that, the thing people hit is assuming this node does the A8R8 patching; it doesn't, it just emits regions, so a bare workflow with no A8R8 Attention Couple downstream does nothing. Check your graph has the A8R8 nodes wired after regions. And keep weight_* in a sane range - these scale attention per region, and values far from 1.0 (like 5.0) tend to produce over-pushed regions rather than "stronger" ones. A/B from 1.0 before you go extreme.