Accurate three-dimensional printing

A system for printing a three-dimensional object comprising:

• an enclosure configured to contain a material bed;
• an energy source configured to generate an energy beam that transforms at least a fraction of the material bed into a transformed material as part of (A) the three-dimensional object and (B) a physical marker, which three-dimensional object comprises a portion that is deformable, wherein the physical marker is connected to the portion, wherein the three-dimensional object is formed while considering a model of a requested three-dimensional object, wherein the physical marker is an addition to the requested three-dimensional object, wherein upon deformation, a position of at least a segment of the physical marker deviates, wherein the energy source is operatively coupled to the material bed;
• a detector that is configured to detect the at least the segment of the physical marker, wherein the detector is operatively coupled to the material bed;
• and
• at least one controller that is operatively coupled to the energy source and to the detector, wherein the at least one controller is individually or collectively programmed to:
• (i) direct the energy beam to transform the at least the fraction of the material bed into the transformed material as part of (A) the three-dimensional object and (B) the physical marker, and (ii) evaluate, or direct evaluation of, a deviation from the position of the at least the segment of the physical marker detected with the aid of the detector, to produce a result.