Optical Illusion
This is a Moire, and it is an optical illusion because of the large-scale interference patterns that can be produced when an opaque ruled pattern with transparent gaps is overlaid on another similar pattern. For the moiré interference pattern to appear, the two patterns must not be completely identical in that they must be displaced, rotated, etc., or have different but similar pitch.Let us consider two patterns with the same step p, but the second pattern is rotated by an angle α. Seen from afar, we can also see darker and paler lines: the pale lines correspond to the lines of nodes, that is, lines passing through the intersections of the two patterns.
If we consider a cell of the lattice formed, we can see that it is a rhombus with the four sides equal to d = p/sin α; (we have a right triangle whose hypotenuse is d and the side opposite to the angle α is p).
Unit cell of the "net"; "ligne claire" means "pale line"
Effect of changing angle
Effect on curved lines
Source- Wikipedia (Moires)
My second illusion because I was not feeling my first one
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