axis. The presented formulas for computing the period pm (the vertical distance between the moiré curves) and the optical speedup (along the vertical axis) are valid for Figure 6. More interesting is the case when the inclination degrees of layer lines are not the same for the base and revealing layers. Figure 7 shows an animation of a superposition images where the inclination degree of base layer lines is constant (10 degrees), but the inclination of the revealing layer lines oscillates between 5 and 15 degrees. The periods of layers along the vertical axis pb and pr are the same all the time. Correspondingly, the period pm (along the vertical axis) computed with the basic formula also remains the same. Figure 8 helps to compute the inclination degree of moiré optical lines as a function of the inclination of the revealing and the base layer lines. We draw the layer lines schematically without showing their true thicknesses. The bold lines of the diagram inclined by αb degrees are the base layer lines. The bold lines inclined by αr degrees are the revealing layer lines. The base layer lines are vertically spaced by a distance equal to pb, and the revealing layer lines are vertically spaced by a distance equal to pr. The distances Tb and Tr represent the true space between the base layer and revealing layer lines, correspondingly. The intersections of the lines of the base and the revealing layers (marked in the figure by two arrows) lie on a central axis of a light moiré band. The dashed line of Figure 8 corresponds to the axis of the light moiré band. The inclination degree of moiré lines is therefore the inclination αm of the dashed line. From Figure 8 we deduce the following two equations: From these equations we deduce the equation for computing the inclination of moiré lines as a function of the inclinations of the base layer and the revealing layer lines: Deducing other known formulas The true pattern periods Tb, Tr, and Tm (along the axes perpendicular to pattern lines) are computed as follows (see Figure 8): From here, using the formula for computing tan(αm) with periods p, we deduce a well known formula for computing the moiré angle αm with periods T: From formula for computing pm we deduce another well known formula for computing the period Tm of moiré pattern (along the axis