DIRC, short for "digital image correlation," is a powerful tool used in the field of mechanics to determine changes in shape and deformation. However, there are several synonyms for DIRC. For instance, optical flow techniques and digital image analysis can be used to achieve similar results. Additionally, photogrammetry and stereo imaging are other useful methods that can be used in lieu of DIRC. Furthermore, image-based modeling and computer vision can also be utilized as synonyms to the term DIRC. Regardless of the specific terminology used, the essential concept behind these techniques is to accurately measure and analyze the changes in a subject's surface over time, allowing for accurate predictions of its behavior and performance.