[Processing] Can Perlin noise return in the opposite direction?

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I wanted to find out the start position from the position of the particles after moving along Perlin noise, but I felt like I couldn't, so I checked it. It seems that you cannot return to the same position just by moving backward normally. If there is a good way, please leave a comment. ### code https://gist.github.com/Nekodigi/8f5a1dea37d738130a637de91f56368c