Trying to understand the noise plugin Tundra

[Quan_Li]

curlPattern simplified v0.gh (26.0 KB)

I am learning Tundra using the official example file.
From what I understand, the Curl component is a function that modifies Perlin noise. I am trying to grasp the logic behind why we need to connect the Perlin noise to the Z input of the Curl function,

If I input Constant values into X and Y, and connect Perlin to Z, does that mean the Curl only modifies the Z direction of the Perlin noise(curlify it?), while smoothing out its features in the XY directions? If this is true, then how do we obtain the tensor in XY direction? Shouldn’t the tensor which obtained by evaluating the points in XY plane all pointing either positive Z or negative Z?

I’m currently learning the very basics of noise functions. If anyone has a good understanding of this, please guide me through it. Thank you very much!

[laurent_delrieu]

Hello
Curl uses a Vector Field (Vector varying on X, Y, Z), I think in Tundra Perlin is a Scalar Field (number varying on X, Y, Z and sometime time)

Curl (mathematics)

From my understanding If vector Z is only changing in Z you will have a Curl vector field just on X (i), Y (j)

[Quan_Li]

Thank you! @laurent_delrieu
I am not sure if I understand it. Can I see this as constant swirling winds being scattered by undulating hills (with the Perlin value input into the Z - slot of Curl)?

I generated this image with ChatGPT.