Use the Flood Fill tool to fill a contiguous area of empty cells or identical tiles with a selected tile.
Select the Flood Fill tool from the toolbarA row of buttons and basic controls at the top of the Unity Editor that allows you to interact with the Editor in various ways (e.g. scaling, translation). More info See in Glossary, or press its shortcut key G.
Select a tile from the Tile Palette window.
At this point, you have two options depending on what you want to do:
To fill contiguous empty cells
Click on an empty cell on the tilemapA GameObject that allows you to quickly create 2D levels using tiles and a grid overlay. More info See in Glossary with the Flood Fill tool to fill all contiguous cells with the selected tile from Step 2.
To only fill identical contiguous cells
To only fill identical contiguous cells, click on a cell that already has a tile with the Flood Fill tool. The tool replaces the tile of all contiguous cells with the selected tile from Step 2.