Ordered dithering turns a continuous tone into a few palette steps by comparing each cell’s tone to a fixed threshold pattern. The matrix prop picks the pattern and cell sets its size.
Bayer matrices
2is the 2x2 matrix: four threshold levels. The coarsest look; a two-colour palette reads like print halftone.4is 4x4: sixteen levels. A good middle ground for chunky grain with smooth ramps.8is 8x8: 64 levels, the default. Smoothest tonal range."noise"uses a random threshold per cell instead of a matrix, for a grainier texture with no repeating pattern.
Cell size
cell is one dither cell in CSS pixels, 1 to 8. It controls resolution more than look: at 1 the dither is nearly continuous, at 8 each dot is a visible square. The shader samples the field once per cell, so larger cells are also cheaper to draw.
Picking a combination
Photographic image dithering looks best at 8 or "noise" with cell 1 or 2. Bold backgrounds read well at 4 with cell 3 to 5. The effect pages have a live matrix switcher on every preview so you can see the difference immediately.