1. A method for modelling physical geological structures, the method comprising: accepting geological data; generating a three-dimensional (3D) transformation between a 3D present day model having points representing present locations of the physical geological structures and a 3D past depositional model having points representing locations where the physical geological structures were originally deposited; accepting an indication to locally change the 3D transformation for a subset of points in a first model of the models, wherein the indication is generated in a computing device using a graphical editing tool represented by a pair of twin 3D volumes, the location, size and shape of which are controllable by a user, wherein a location of a center of one of the twin 3D volumes is chosen by the user to be located on a horizon in the present day model or on a horizontal cross-section in the past depositional model; locally changing the 3D transformation for the subset of points; and displaying a locally altered version of the first model.