Cell of Interest

A cell of interest is the specific tile on a building or natural structure where a Duplicant interacts with it, delivers materials to it, or where its output is produced. These cells are important for planning automation, pathing, and layout, since many buildings do not use their visible center as the functional tile. Knowing the correct cell lets you place things like Motion Sensors, lights for the Well Lit bonus, Carpet Tiles for the Tickled Tootsies bonus, Weight Plates, mesh tiles, and Auto-Sweepers in the right spot.

There are three main types of cell of interest:

• Dupe Interaction Cell: the tile a Dupe must stand on to operate the building.
• Delivery Cell: the tile that accepts item deliveries from a Dupe or an Auto-Sweeper.
• Material Drop-Off Cell: the tile where the building’s output is placed.

Cell coordinates are usually written as rows from bottom to top, with A being the bottom row, B the row above that, and so on; columns are numbered from left to right starting at 1. For example, A1 is the bottom-left tile of the building footprint. A blank entry means that the cell type does not apply to that building. Some buildings can be rotated or reversed, which changes the relevant tile.

For natural structures such as geysers, Volcanoes, and vents, the cells of interest are tied to the four tiles of Neutronium that generate beneath them. In those cases, the Dupe interaction point is one tile above the center-left Neutronium tile, and the material output point is two tiles above that same tile.

The system is especially useful when designing compact bases and automation-heavy production lines. If a Sweeper cannot reach the delivery cell, the building will not receive inputs; if the drop-off cell is blocked, outputs may appear in an unexpected place or fail to route cleanly. Several buildings also have misleading animations, so the functional cell is not always where the visible animation suggests.