Boy's surface and Steiner's Roman surface are two famous immersions of the real projective plane into 3-dimensional space. This animation shows a homotopy (a smooth deformation) between the two surfaces. You can use your mouse to rotate the surface and to zoom in and out.[br]See: [url=https://mathworld.wolfram.com/BoySurface.html]https://mathworld.wolfram.com/BoySurface.html[/url]