In MetaFlight, a virtual texture is the type of dataset used to describe a, usually large, image that is organized into a multi-level system of smaller image tiles.
It is called virtual because the collection of tiles together makes up one single integrated image.
A virtual texture can be mapped to a terrain skin with virtual texture coordinates or tiled texture coordinates. Virtual texture coordinates map area covered by the virtual texture from 0.0 to 1.0, while tiled texture coordinates map each tile within the virtual texture from 0.0 to 1.0. The texture mapping technique is a function of the capabilities of the runtime system. Vega Prime supports both texture mapping designs.
The virtual texture dataset adds to the base definition of all grid datasets; image attributes (number of channels, bits per channel), a substitution texture. Virtual texture datasets also impose strict constraints on the grid structure of the database.