Both share the same idea, but math is certainly different. Those cymatics patterns are solutions of the u_tt = u_xx + u_yy equation with t modulated by a sine w

Both share the same idea, but math is certainly different. Those cymatics patterns are solutions of the u_tt = u_xx + u_yy equation with t modulated by a sine wave and the images themselves are reflections of light in the u(x, y) surface.