A 3D scanner for scanning objects placed by an operator in a scan volume of the 3D scanner, where the 3D scanner comprises: - an optical scanning unit configured for recording geometry data of an object placed in the scan volume, the optical scanning unit comprising: - a light source arranged to project a beam of probe light into the scan volume; and - an image acquisition unit, comprising at least two 2D cameras arranged to record 2D images of light received from the object placed in the scan volume; the scan volume being defined by at least a part of an overlapping section of cones representing field of views of the individual 2D cameras, and - a control unit comprising a data processor and a non-transitory computer readable medium encoded with a computer program product comprising readable program code being executable by the processor to cause the processor to: - monitor the scan volume while the operator moves the object into place in the scan volume by using 2D images recorded by the image acquisition unit, - detect movement of the object in the scan volume in the step of monitoring the scan volume by analyzing monitoring data acquired for the object at different points in time, - initiate 3D scanning when the object is determined to be at rest in the scan volume, and - generate a digital 3D representation of the object from the recorded geometry data after the step of initiating 3D scanning. - an optical scanning unit configured for recording geometry data of an object placed in the scan volume, the optical scanning unit comprising: - a light source arranged to project a beam of probe light into the scan volume; and - an image acquisition unit, comprising at least two 2D cameras arranged to record 2D images of light received from the object placed in the scan volume; the scan volume being defined by at least a part of an overlapping section of cones representing field of views of the individual 2D cameras, and - a light source arranged to project a beam of probe light into the scan volume; and - an image acquisition unit, comprising at least two 2D cameras arranged to record 2D images of light received from the object placed in the scan volume; the scan volume being defined by at least a part of an overlapping section of cones representing field of views of the individual 2D cameras, and - a control unit comprising a data processor and a non-transitory computer readable medium encoded with a computer program product comprising readable program code being executable by the processor to cause the processor to: - monitor the scan volume while the operator moves the object into place in the scan volume by using 2D images recorded by the image acquisition unit, - detect movement of the object in the scan volume in the step of monitoring the scan volume by analyzing monitoring data acquired for the object at different points in time, - initiate 3D scanning when the object is determined to be at rest in the scan volume, and - generate a digital 3D representation of the object from the recorded geometry data after the step of initiating 3D scanning. - monitor the scan volume while the operator moves the object into place in the scan volume by using 2D images recorded by the image acquisition unit, - detect movement of the object in the scan volume in the step of monitoring the scan volume by analyzing monitoring data acquired for the object at different points in time, - initiate 3D scanning when the object is determined to be at rest in the scan volume, and - generate a digital 3D representation of the object from the recorded geometry data after the step of initiating 3D scanning.