Shape generator is a component in Tinkercad that contains custom shapes that are designed and shared by the Tinkercad community. Note that some of the shapes available here may not work and cause problems in your design while others may work very well. You can use the ones available in Featured section, since they are contributed by Autodesk and therefore, they are stable. shapes have certain properties that you can change to get different forms. Some examples of shapes here include the Extrusion, Ring, Voronoi, Metric gear, ISO metric thread, Image Generator, etc.
We will start by dragging the Extrude Shape Generator into the canvas and see what we can do with it. The inspector window now shows a sketch window with a grid, which will change your shape in the canvas as you drag the control points. There’s a Settings button on the sketch editor that allows you to snap to the grid. Use this tool if you want to be very precise.
By manipulating the handles, you can create smoother curvatures or convert the curve into a point if you take these handles all the way into the centre point. You can even self-intersect the volume if you keep dragging the handles past the centre. The extruded shape will react to each of your changes.