This shader has an effect of rolling (like a paper) a procedural mesh, being a simple generated cube.
On the object Paper set on roll_shader_effect scene, open the material settings and change the value '_Unrolled Angle' which contains the 'Rolling' shader.
The basic code was provided by the following link: https://gamedev.stackexchange.com/questions/151904/how-can-i-roll-up-a-plane-with-a-vertex-shader