Hi I’d like to program a sin on Circle. Any ideas image under.

Is this going to be in the UMG, or do you mean on a sphere?

Dear Mateusz88,

you can work out the math and find out that the formula you are looking for is the following:

```
x = (R+a*sin(n*t*s))*cos(t*s)
y = (R+a*sin(n*t*s))*sin(t*s)
```

where:

**R** is the *Radius*

**a** is the *Amplitude*

**n** is the number of sines functions along the circle

**t** is the *time*

**s** is the *speed*

At the end, remember to add the center of the circle

You can either build the formula in your blueprint, or use a custom Math expression node, like in the following screenshot:

And this is the final result:

If you need other clarifications, I will be glad to help.

Dear FSapio,

Everything is working fine. Thank You for answer. I have another question about this shape. Is it possible to fill it with instance meshes.

Thank You for Help.

I mean on a sphere like hills on a planet

Ok, but you have the answer now…

By “fill it”, do you mean along the shape, or also inside it?

To place something along the shape, you can put an angle instead of the time and use 1 for the speed. This will give you a point along this shape at that angle from the center. Just divide 2 Pi by the number of meshes you want along the shape, and use the formula every angle that you found in the division.

To place something inside the shape, let’s say randomly, you can change the radius between a min and a max.