Hypervelocity impact experiments were performed on transparent materials, SiO_2 glass and polycarbonate, to investigate the impact-induced damage process. Stress wave propagation and damage evolution associated with hypervelocity impact were visualized using a high-speed video camera. Recorded images clearly showed how stress waves propagate and interact each other, and how damages form and propagate during hypervelocity-impact event. For examples, the interaction of the transversal wave with the longitudinal wave reflected from rear surface initiated the drastic nucleation of damage points in SiO_2 glass. In the case of polycarbonate, delamination was initiated by the interaction of the reflected rarefaction waves from both side surfaces. Such information provides a valuable insight into the fundamental understanding of the hypervelocity-impact damage process on glass, ceramics, and polymer materials.