Grass and twitches between tiles

[yaschan@gmail.com]

I would like to make grass look like it is growing from crevices between tiles. I would like to prevent the appearance that the clumps of grass are growing on top of tiles.
How should one approach this kind of task?

[rwnet]

Just use Tile Sampler for the grass and twitches and plug in a mask for the tile sampler and you are golden