◯ Shape of N-Polygon

Need a triangle for a composition? A hexagon for a "futuristic tech UI" ControlNet pass? Or something with 200 edges that reads as a soft ellipse? Shape of N-Polygon [DPaint] is the one node in the Dream Painter pack that covers all of those, because the polygon's edge count is just a slider. It's from alt-key-project/comfyui-dream-painter, the MIT-licensed kit for drawing simple geometry that guides image generation rather than being the final art - the README calls it "quick-and-dirty," and that's the whole point: you're building the structure map, not the artwork.

What it actually does

The node computes N points around a center using plain sine and cosine - one vertex per edge, laid out on an ellipse defined by width and height - and returns them as a single filled polygon shape. Set edges to 3 and you get a triangle; 5, a pentagon; 28, something that only squints at being round; up to 1000, a perfect circle. The docstring calls it a "rounded polygon," but don't read anything fancy into that - it's a regular polygon whose corners sit on an ellipse, not a polygon with filleted corners.

The inputs you actually set:

• edges - 3 to 1000. The whole point of the node. 3 for a triangle, 5–6 for classic shapes, 50+ for a disc. This is the only input you'll touch most of the time.
• shape_width / shape_height - the ellipse the vertices ride on. Equal values give a regular polygon; stretch them apart and you get a squashed, lens-shaped one. Defaults are 0.75/0.75, in the normalized 0–1 space Dream Painter uses.
• center_x / center_y - where the polygon sits. Default 0.5/0.5 is dead center of the frame.

Everything outputs through a single SHAPE socket. The node renders nothing on its own - a shape is just a list of vector points until you draw it. Feed the SHAPE into Draw Shape As Bitmap [DPaint] to rasterize it, then Bitmap To Image & Mask [DPaint] turns that bitmap into an IMAGE and a MASK. The IMAGE can go straight into a ControlNet as a structure condition (it pairs naturally with the scribble/canny-style conditions - rough geometry in, the model fills in the surface); the MASK is handy if you want a masked region shaped like a polygon for inpainting or a detail pass.

Installing it

It ships with the whole pack, so the install is the same as every other Dream Painter node:

cd ComfyUI/custom_nodes
git clone https://github.com/alt-key-project/comfyui-dream-painter
cd comfyui-dream-painter
pip install -r requirements.txt

Or search "Dream Painter" in ComfyUI Manager. Restart ComfyUI afterward. No model files, no keys, nothing heavy - just Pillow, scipy, numpy (pinned <2.0.0), and a few small helpers. That numpy pin is the one dependency gotcha: pip may downgrade a numpy 2 environment, which can upset other packs.

Common gotchas

Two things to keep in mind. First, the edge count grows visually fast: 12 edges already looks roundish at small sizes, so if you want something that reads as a polygon, stay in the 3–8 range. Second, remember the fill setting on Draw Shape As Bitmap - a polygon with fill: no renders as a stroked outline, which is a very different ControlNet condition than the solid version. Render to a bitmap and preview before wiring it into the sampler; with a shape this cheap to regenerate, iteration is basically free.