1. A method, comprising: projecting flushing fluid into an optical field of view of an imaging system disposed on a downhole tool; directing a pattern of light, the pattern having a plurality of spots, onto a target in the optical field of view via at least one laser of a light source of the imaging system; receiving light directed from the target by an image detection plane having a plurality of detectors; determining three-dimensional shape information of the target based on the light directed from the target and received via the plurality of detectors by comparing differences between the pattern directed onto the target and a pattern of spots directed from the target onto the image detection plane; determining a characteristic of the target based on the three-dimensional shape information; and performing dynamic modification of a search area containing the target according to pattern changes.