oscillating transform value on X axis, loopable animation

[crispr_boi]

I am trying to adapt this tutorial by Rohan Dalvi called: HOUDINI KINEFX - 1 - Basic parenting

https://www.youtube.com/watch?v=RTNVyGbpwv0&t=917s

At around 4:46 he is using a transform node to define the distance between the parent and the child.

The tz (transform in the z axis) parameter is used to define the distance from the parent to the child.

My goal: I want to create a loopable animation, have the child revolve around a parent one time per animation (rotating the parent 360 degrees results in the child revolving once around the parent), but I want to vary the distance from child to parent in like an oscillating fashion.

I want an imperfect circle meaning a changing radius, but create a seamlessly loopable animation.

In this example, the child is translated by 3, but my goal is to change this value in a periodic fashion. Let's say between 2.7 and 3.3. Sin wave?

1. I want to have easy control over the the distance between parent and child, without keyframes (I just didn't know what to google or how to adapt snippets of code for my problem)

2. Control the frequency of it happening (x times per animation)

3. The whole thing should result in a seamless loop.

 

Maybe asking for too much, but:

Is it possible to have smoothly changing random z transform values, or at least seemingly irregular and make it loopable?

I am thinking of something like the wiggle expression in After Effects, which would move a point in random directions but smoothly, and if I recall correctly this was loopable.

wiggle(freq, amp, octaves = 1, amp_mult = .5, t = time)
wiggle(3,15);

https://www.schoolofmotion.com/blog/wiggle-expression

 

 

 

odforce_oscillating_transform.hiplc

Edited June 22, 2021 by crispr_boi

[crispr_boi]

Okay I found an okay solution, it's fairly simple, so a method to make it seem or be random or look less regular, would still be much appreciated.

But I found this old tutorial from 2009, in which Dave Kaul shows: Houdini, sin, cos, smooth functions

https://www.youtube.com/watch?v=aH0KGGOlDkc

I used his snippet of code:

sin($F*3)*0.2