I was following this tutorial and had a few questions about nose.

http://www.sidefx.com/index.php?option=com_content&task=view [sidefx.com]

In C4D they have other options for noise that are not available in Houdini
Here is a list and a preview image:
http://www.cybergooch.com/pages/c4d/noise/c4d_noise.htm [cybergooch.com]

In Maya they have Billow, Wispy, Brownian, Crater, etc.

Does anyone have any insight into the C4D/Maya textures if they are based on shaping or warping, or are they completely different noise algorithms altogether.

Most of these noise textures or something similar seems like it can be made in Houdini by “shaping” and “warping” the 6 or so basic noise textures. Its always nice to have more options for basic patterns.

I'm not sure if there is an exhaustive list of noise types anywhere? from the demo, there is simplex, perlin, sparse, worly, voronoi, cell, alligator

are there more?

A mishmash of terms here. All intended to confuse and obfuscate things.
And then there's “Turbulize”. LOL!

Billow and Crater are folded turbulent or fBm (aka Brownian) better known as fractal Brownian Motion noise. Most of the more interesting noise patterns here are folded.

It is very common to take turbulent noise which in itself can be constructed of fBm and take the absolute value which results in a noise that looks billowy or crater. All depends if you push it up and out or in.

The problem with folding noise like this for displacements is that it can cause aliasing artefacts. Whenever you clamp or abs any continuously variable pattern, you will get an infinite amount of info at the 0 inflection point that needs to be antialiased. These days with more things using raytracing, the aliasing you would have gotten with Reyes shading isn't so much of an issue these days. Just fire more rays. But it does still affect displacements.

One time-honoured approach to avoid aliasing and displacements is to port your vex network off to a VOP COP and generate a big ass texture map, 8k or higher and then apply as a texture map. Don't have to calculate expensive noise shaders all the time either and you get anti-aliasing for free with texture filter look-ups and mip levels in .rat files in Mantra.


As for Wispy, this is generally very heavily thresholded anisotropically scaled noise where you only see the peaks or valleys of the noise. Doesn't matter what noise pattern really. The trick is to make the wisps coherent and there is the art with this noise form. Because the wisp is a very narrow band of the noise, it is prone to temporal aliasing or flickering. Resolution works well here if it is a surface texture.


If you want an exhaustive list of noise options, just use the Unified Noise VOP. You can wring just about any type of noise pattern from that VOP. And it for the most part is fairly well anti-aliased.

Then you too can come up with your own name for your noise shaping pattern and just add to the growing list of descriptions out there.

In the end it's all just noise.

Many of these noise pattern names arise from the authors names and have little bearing on the look of the noise, adding to the mystery. The classic is Perlin Noise of course. This makes google searching for some of these noise type terms next to impossible unless it is somehow immortalized in a software app interface and then it is taken as fact. A must have feature! LOL!


I think the only one who didn't name noise after themselves is Kenton Musgrave who took noise to a whole new level in the 80's and 90s. Much of his work along with other noise authors can be accessed from the Texturing and Modeling - A Procedural Approach book here:

http://www.amazon.com/Texturing-Modeling-Third-Edition-Procedural/dp/1558608486 [amazon.com]

After going through this book, you'll get a newer and deeper appreciation for noise.

Are there any unique new noise patterns out there? And where to find them?
Best to follow any and all siggraph papers and see what is up and coming.


If there are some guidelines to working with noise beyond what Ari talks about, it is when layering noise try to separate the base frequencies by a factor of 2 or doubling or halving the frequency of each different layer of noise ( similar to lacunarity wrt fBm). For example when layering the Ocean displacements as layers, using the golden ratio of 1.681 works quite well (which for arguments sake is sort of around 2).

Thresholding noise by shoving noise in to bandwidth, hi-pass or lo-pass filters and then using these regions to trigger other noises can create some nice organic shapes. This is used to create many of the complex noise patterns on that page. Those also happen to be the ones with the wonky names. As though Houdini doesn't have wonky names… ops:


One example is a noise pattern called “Gloop” where you take cellular noise but you square the result. Similar to folding as you get only positive values but you also get nice gloopy rounded bubbles reminiscent of underwater coral.


I hear you about the presets. Good idea to have expanded presets for VOPs that ship with Houdini.

great response!

That unified noise looks crazy. I like it.

I'm definately going to check out that book, however most of the examples look like renderman or C++ code. I'm not familiar with either.

Thanks

Its should be edit on camtasia and mute the noise well. after that done it.