Sine wave on the environment texture

Question

I am trying to create a Sine wave that goes around the environment texture (something like what is shown in the attached image)

I have tried to mess up around with the math nodes.

So far I am trying to mess up a bit with the math nodes and I have made this:

Which gives this as a result:

This makes sense, but I cannot figure out a way on how could I do what I want. How could I create and deal with this kind of issue?

btw: I am quite familiar with trigonometry and mathematical functions as my background is engineering.

Answer 1

I'll take Lemon's excellent answer and modify it to use Blender's built in textures for those of us who don't work so well with math nodes.

We can run a large wave texture through a color ramp to squeeze down and isolate a solid line on the z axis. (Rough equivalent to running z channel through compare node)

We can create a second wave texture using a radial gradient as the vector to define a period for our sine wave. (Radial gradient outputs the arctan2 operation mapped from -pi to pi.)

Then we can mix this period mask into our z coordinate, and basically we're telling blender to pull down the z coordinates in the white spaces, and controlling how much with the mix factor.

Finally, if you want to recreate the "drawn" feeling of the reference, you can mix noise into the main texture coordinate.

Answer 2

That can be this kind of settings:

Base nodes (with X and Y centered from "generated" coordinates, using "vector mapping")

• Take the angle through "separate X Y Z" and "artan2" using X and Y.

• Get the "sin".

• And compare it to Z value.

Tuning (in green above)

• Multiply the angle with some value to have the wave amount.

• Multiply Z to handle the wave height.

• Use some value to tune the wave line height.

here a blend file for 2.8: