Abstract: Method, apparatus, computer program and data carrier for modeling a multidimensional, heterogeneous structure using a digital processing unit, by means of a grid built up of stacks of multidimensional cells. A cell is bounded by boundary surfaces and represents at least one property of the structure. The composition of a stack, the position of the stacks in the grid and the properties represented by cells are stored in memory means by the processing unit. For modeling a discontinuity, a respective stack is divided into two or more substacks separated by separating surfaces. The composition and the position of the substacks in a respective stack are stored in the memory means. The modeling method enables an accurate and fast computation of properties of the modeled structure or space.