GAMGI supports multiple, unlimited, layers for each window, allowing users to move and copy objects between different layers and see multiple layers simultaneously, if they wish. A layer can own all kinds of GAMGI objects, except bonds, windows and layers. In particular, layers are the only GAMGI objects that can own lights.

Most of the layer functionality is already in place, including perspective and orthographic projections, full control over projection and model view (like a photographic camera) parameters, inside and outside visibility, background color, plus undo and save history mechanisms to keep and recover the whole contents of each layer, for as many levels as previously defined. Perspective projection is better to simulate realistic views but the orthographic projection (mostly used in architecture) is usually preferred for most work related with building and viewing structures, because these are not distorted by perspective. The projection parameters, that control the matrix transformations related with the projection of the 3D space on the screen, are fully controlled by the users.