You can find this filter from the image menu through
-> -> ->
The Qbist filter generates random textures. A starting texture
is displayed in the middle square, and different variations
surround it. If you like one of the alternative textures, click
on it. The chosen texture now turns up in the middle, and
variations on that specific theme are displayed around it. When
you have found the texture you want, click on it and then click
OK. The texture will now appear on the currently active layer,
completely replacing its previous contents.
Three more or less random examples of qbist renderings.