Optical Illusion Generator

The OpticalIllusionNode generates the four classic "my eyes are lying to me" patterns - checkerboard, concentric circles, parallel lines, and an Archimedean spiral - as clean two-tone images. It's the simpler sibling of the pack's OpticalGeometricNode, and the spiral alone is worth the install: it's the classic "the whole picture is spinning" illusion, perfect as a hypnotic background or a canvas-filling motif.

How it works

Four separate drawing routines, all outputting a square image of size × size pixels in your two chosen colors:

• checkerboard - the standard alternating grid. The humblest entry, and the one people least need a node for, but it's here for completeness.
• circles - concentric rings from the center out, which is the classic "the center of the image is bulging toward me" illusion.
• lines - parallel lines; dense enough they start to shimmer.
• spiral - a proper Archimedean spiral, drawn parametrically. This is the crowd-pleaser. Stare at it, look away, and the wall moves.

frequency controls how many elements exist (rings, lines, spiral turns), and line_width sets the stroke. It's all pure Pillow math - instant, no GPU, no models.

The inputs that matter

• illusion_type (default checkerboard): the four above.
• size (default 512, range 128–2048): square output dimension.
• frequency (default 10, range 2–100): how many rings, lines, or turns.
• line_width (default 3, range 1–100): stroke thickness. Note this one goes to 100 - a thick-line spiral looks very different from a thin-line one, and both are good.
• color1 / color2 (default #FFFFFF / #000000): the two-tone palette.

One IMAGE output. Wire it to Save Image, or use it like the rest of the pack's generators - as a texture, a background, or a pattern input to the autostereogram node (the spiral genuinely shines there).

Install

Part of orion4d/illusion_node, "ComfyUI Illusion & Pattern Nodes", under the "illusion" category. Install via ComfyUI Manager by searching "Illusion", or:

cd ComfyUI/custom_nodes
git clone https://github.com/orion4d/illusion_node.git

Restart ComfyUI. The pack depends only on numpy, torch, and Pillow - all already in a stock ComfyUI - so there are no model downloads and no extra package installs.

Common issues

The usual complaint is that the output "doesn't look like an illusion" - which almost always means the two colors are too close together, or frequency is too low to produce the vibration effect. High contrast (black on white) and a mid-to-high frequency are what make these read. Also note the output is square and there's no built-in crop, so for non-square uses you'll resize or crop downstream. And if you're comparing against the OpticalGeometricNode, the difference is style: that one does geometric design (starbursts, hexagons, wavy grids), this one does the four canonical illusion motifs. If you only install one, the spiral probably wins.