A process for producing at least one three-dimensional object by solidifying a solidifyable material, comprising the steps of: providing an object carrier capable of carrying the object to be produced; providing a material capable of solidifying when subjected to energy supply; bringing a solidifyable material carrier/provider in a position to carry/provide solidifyable material at least in a building region where solidifyable material is to be solidified; supplying, to the building region, energy capable of solidifying the solidifyable material; and sensing, measuring and/or controlling a condition selected from the group consisting of pressure and/or strain. Alternatively or in combination, contact pressure, fluid pressure and/or material flowability can be sensed and/or adjusted.