The World of an OpenMW game is composed of cells. Each cell consists of an immutable part (stored in the record store) and a list of objects, which make up the mutable part of the world model.
- An active cell refers to a cell that is in the currently rendered scene.
- A cell being loaded refers to the objects in the cell having been loaded from the game files, ready to be used by scripts or other means. Once loaded, a cell is never unloaded, unless you start a new game or load another saved game. Note: some code/other documentation that may not be particularly concerned with the world model will incorrectly use the term 'loaded' as meaning 'active', do not confuse the two!
Interiors & Exteriors
These are the differences between interior and exterior cells:
- Interior cells are accessed by an ID, which is identical to the user-visible cell name. (except for the Russian version of Morrowind, which uses a separate translation mechanism)
- Exterior cells are accessed by a coordinate pair and can have an optional name. Exterior cells are arranged in the regular grid which can have holes and an irregular outline.
- Only exterior cells have terrain
- The sky is optional in interior cells
- Only one interior cell can be active at any time. In this case no exterior cells can be active
- Multiple exterior calls can be active at the same time (in the default configuration the cell the player is in and the eight neighbouring cells). In this case no interior cell can be active.