The present invention relates to a method of determining layer thicknesses (t) of a three-dimensional model (1) for generation with an additive manufacturing apparatus, the method comprising: a step of determining the layer thicknesses (t) according to an adaptive slicing algorithm in which the thickness of a layer (2) is calculated through a relation based on the inclination of the normal vectors (n) of the surface elements (s) of the 3D model (1) which at least partly enclose the layer (2) from a horizontal direction (x; y) the method being characterized by further comprising: a step of selectively imposing on at least one surface element (s) of the 3D model (1) a precision requirement out of one or more selectable different precision requirements which respectively differently alter in the determination step the relation with respect to the inclination of the normal vector (n) of the said at least one surface element (s) which allows, through the altered relation, the layer thickness (t) to obtain a value smaller or larger than the layer thickness (t) determined through the unaltered relation.