Hello,
I am following a tutorial where a NOISE CHOP is used to animate a series of points on a LINE SOP. To do so, absTime.frame is being used on the rotation around the z-axes. I can’t quite visualize what this means in practical terms, although the effect is exactly the points moving up and down along the Y axes.
Thanks!
Hi,
As I understand it, the noise algorithm uses transform information (ie: a given position in a 3D field) as part of the coefficients that are used to compute the noise value. Transforming that field allows you to change the coefficients and, so modulate the noise.
This is a fair bit easier to conceptualize if you play around with the noiseTOP.
You’ll often see people simply modulate the “Translate” parameter to generate continuously evolving noise, though there are some caveats there.
In your case, by modulating the rotation parameter you’re able to generate modulating noise values that smoothly loop, since rotating by 360 degree brings you back to where you started.
Thank you, Florian. Noise TOP is easier to understand as the translation movements, especially on the X and Y axes, have a direct correspondence with what I see (the pattern moves on the X/Y axes altogether), whilst on the Z axes is a bit harder to understand what’s going on, but it’s fine.
For the NOISE Chop, instead, I understand there’s not a visual match between what I am manipulating and what the object does, but it’s fine, I think it requires a bit of a leap of faith 
Thanks!
Yup, the Z axis translation is showing you different 2D ‘slices’ in the 3D noise field when you adjust the z translation in the noiseTOP. I just remembered that there is actually a pretty intuitive presentation of smoothly interpolating noise algorithms here:
The noiseCHOP, as far as I know, is not a shader, but something that’s optimized for CPU evaluation, but the principles ought to be largely transferrable.
Ohh that’s a cool reference, thank you!
Hi again, sorry if I’m inundating you with stuff but, as often happens, thinking about your question made me want to explore this further. I wound up building a 3D noise visualizer that lets you manipulate the position and rotation of a noise function and shows the result in 3d.
it’s attached if you’re interested.
noiseViz.toe (5.7 KB)
edit: also added scale for more fun viz
That looks cool! I’ll probably get back to this after digging into shaders. Thanks for sharing!
