The Block Dissolve effect makes a layer disappear in random blocks. The width and height of the blocks, in pixels, can be set independently. At Draft quality, the blocks are placed with pixel precision and have sharply defined edges; at Best quality, the blocks can be positioned with subpixel precision and have soft edges.

This effect works with 8-bpc and 16-bpc color.

Original (top left), and with effect applied (bottom left and right)