CC3’ maps are stored in a vector format. Instead of using the array of dots found in bitmaps, CC3 stores maps as a collection of geometric shapes that combine to make the map. These are stored in a drawing’s database. Whenever you change the view in the viewing window, CC3 re-calculates what you can see from the database and displays it.
CC3 work very well with raster images, allowing you to zoom in very close with no loss of detail until you are too close for the view to be useful. Raster images are not stored in the drawing, CC3 references them, meaning that drawings remain very small.
CC3’ file format has four major advantages over purely raster-based images (e.g. GIFs and bitmaps). First, you can zoom in and print without any loss of detail. Second, the files created are very small in comparison with similarly detailed pure raster maps. Third, you can hide and show relevant features using layers and sheets. Finally, CC3 uses the same file format as AD&D Core Rules Campaign Mapper® and TSR’s Forgotten Realms® Interactive Atlas.
The only downside of vector format is that there is no fixed file size; this can lead to large drawings. The speed at which the maps redraw depends on the number of drawing objects (entities) within the drawing database. This means that large drawings takes a long time to refresh on slower computers. See Redraws for techniques to reduce this problem.