Noise on ramp transition (edge)

[Neekozo]

Hello amazing Houdini people!

 

I have been struggling with what i thought would be an easy thing to do. (It probably is but my brain cant figure it out)

In the image below you can see a unified noise (static) being multiplied with ramp paramater. 

 

Output becomes then noised ramp.

 

What i want to achieve is noise ONLY on the edge of the ramp. 

Kind of like growth. 

 

Any advice? Losing my mind here  have been using fit and clamps but cant seem to do it.

 

One thing to note is taht im not actually animating the ramp, im animating the UV coordinates.

 

 

 

 

[velurpasha]

 

noise_shift_001.hipnc

[Neekozo]

Wow! 

 

Thanks so much! I will pick this apart, BIG thanks Velur!! 

[Neekozo]

Hello again!

 

I was trying out your setup, it works for all intents and purposes. 

 

I am just wondering if there are other ways to accomplish this? 

[HundredsofBears]

Bumping this old thread in case anyone else finds themselves in a similar boat where they're drawing a blank on this technique and end up googling "Houdini noise transition".

The trick is to first form your gradient using a value, in this case the x position along a grid...

...and then add noise to that value.

For a deeper dive into this kind of thing, definitely check out this series of classes by Main Road Post and this brilliant page by Kiryha. 

Hope this helps.