# How to make cylinder to sine wave plane animation?

I'm trying to apply boolean cut to a plane which turned into a cylinder with simple deform modifier and than turn that cylinder into a plane again (something like this which i saw in a Numberphile video). First i create a plane, give it enough loop cuts than add simple deform, add rotated cube for boolean operation but when i apply boolean modifier, mesh looks like this.I don't want to apply simple deform modifier because i'll animate cylinder to plane transition. What i am doing wrong? Why does applying boolean modifier messes up geometry?

• Hello and welcome. While files, images, and external videos or links may be helpful additions they should not be the only way to obtain information about your issue. Don't make understanding your question rely on downloading a file, watching a video or visiting an external site. Use the builtin tools to upload images or gifs, along with thoroughly explaining the problem in written form so it can be indexed and searched for thus helping future visitors with similar issues. Nov 18 '21 at 10:21
• There must be an smart way to do it but if you begin with a plane (object A), give it a Boolean modifier then a Surface Deform modifier with a second plane (object B) as Object, bind. Give object B a Simple Deform/Bend and bend 360° on Z. Here is what it gives when you unbend: zupimages.net/up/21/46/1q9y.gif Nov 18 '21 at 11:02

## Dynamic Paint

Once you set up your plane with a modifier, and add a cube, go to physics tab and dynamic paint for both:

• the cube - brush, paint color black
• the plane - canvas, Image Sequence format, increase resolution (it's just one frame so I increased it to 2048), frame end the same as frame start (again, just one frame), initial color white, set output to a place where you can easily navigate later and bake.

Now select the plane, in Material Properties > Settings change Blend Mode to Alpha Hashed or Alpha Clip. Modify the nodes of the material by adding an Image Texture node and loading the baked canvas. Connect its Color output to the Principled BSDF's Alpha input.

Now animate the modifier:

You can use a single object, by animating the alpha in the material.

Why does applying boolean modifier messes up geometry?

Because you apply it before the Simple Deform modifier, so you apply it on the flat plane.

..Late to this, but an option would be to create a plane, with a sinusoidal top edge:

• Create a Z math-function surface, sin(pi * (x - 0.5)) as shown..