Animated Polka Dots (Purz)

Polka dots are the friendliest pattern on the internet, and PurzAnimatedPolkaDots makes them move: a grid of dots that swells, ripples, and shifts frame by frame as a wave rolls through. It's the kind of texture that instantly reads as "video," and because the dots are drawn in a regular grid, the motion stays satisfyingly rhythmic instead of chaotic.

It's one of the four Purz/Patterns/Animated nodes in ComfyUI-Purz, the utility pack by PurzBeats (a Comfy Org staffer). Same wave engine as the animated checkerboard and stripes - the difference is the base pattern: this one uses a dot grid, with an extra stagger option for the classic bricked layout.

How it works

Two textures, one wave. The node draws a polka-dot grid (regular or staggered), generates a moving wave texture with a phase that advances each frame, combines the two with a math operation, and maps the result to a color ramp. Output is a batch of frames you can play back, combine into a video, or use as an animated background behind an img2img pass.

The dot geometry is where you get the most mileage:

• dot_radius - 2–100. Big dots read as bold '60s graphic design; small dots with wide spacing read as fabric.
• spacing - 10–200, the center-to-center distance between dots.
• stagger - boolean, on by default. This offsets alternate rows (the brick layout) instead of a plain square grid, and it genuinely changes the rhythm of the pattern. Turn it off and you get a tidy grid instead.

The inputs that matter

• width / height - canvas size (64–4096).
• background_color / dot_color - hex colors. The ramp endpoint defaults follow the same pattern as the other animated nodes.
• frame_count - number of frames, up to 300. This is your video length.
• wave_type / wave_direction / wave_shape - the motion engine. wave_direction defaults to radial, which makes the dots breathe from the center outward - the most satisfying default of the four animated nodes. Switch to horizontal for a scrolling shimmer.
• wave_scale - wave frequency; lower = slower, broader ripples.
• wave_factor - wave strength, 0–2. Zero = a perfectly static polka-dot texture.
• math_operation - how the wave modulates the dots (add, multiply, maximum, sine…).
• reverse_phase - flips the motion direction.
• color_ramp_type - linear, ease, b_spline, cardinal, constant.

Output is image, an IMAGE batch with frame_count frames.

Installing it

ComfyUI Manager - search ComfyUI-Purz - or:

cd ComfyUI/custom_nodes/
git clone https://github.com/purzbeats/ComfyUI-Purz.git
cd ComfyUI-Purz
pip install -r requirements.txt

Restart and you're in business. Requirements are OpenCV, Pillow, torch, numpy - nothing to download beyond the pack itself. Slider widgets on modern ComfyUI make dialing wave_factor and wave_scale genuinely pleasant.

Where people get burned

Two things. First, don't set dot_radius larger than half of spacing - the dots overlap and you lose the polka-dot look entirely (you get blobs, which is fine if that's the vibe, confusing otherwise). Second, with math_operation set to something like divide or modulo, the dots can get clipped into hard-edged crescents; if that happens, drop back to add or multiply. Everything else is just taste. And as always with animated nodes, keep resolution × frame_count reasonable while you're iterating - prototype at 512, render big when you're happy.