Radial rays overlapped gives a circular moiré pattern. Parallel lines and radial rays can provide the famous Dinostratus Quadratrix, a curve studied by Hippias of Elis in 430 BC and by Dinostratus in 350 BC, cf. en.wikipedia.org. GeoGebra illustration (.html).
Please, turn the rotation on and off by the button and click on/touch the image and move it. Reload = Readjust.