Three Practical Uses for Noise — The Swiss Army Knife of VFX

Three Practical Uses for Noise — The Swiss Army Knife of VFX

VFX artists can wield noise in just about any way they see fit, and we're covering 3 practical ways to use it!

You know what it is and you’ve used it before: noise. Though fundamentally simple, it’s one of the most versatile tools in visual effects. Once you put it to the test, you begin to see its value! 

The beauty of noise as it’s used in VFX is how it defies the traditional definition. Merriam Webster definitions for the word throw out terms like “unwanted”, “unpleasant”, and “meaningless”, but in true effects wizard fashion, we make it have meaning! 

You probably wouldn’t even think about it if you saw the character on the right alone, but when compared to the character on the left who has no noise applied, it’s clear how even the slightest addition of variety to the color gives the character some style and depth.
There are thousands of uses for noise that can become shockingly specific — I once used noise in 3D material authoring suite Substance to generate patterns of cookies in a procedural ice cream texture. 

For now, let’s stick with three of noise’s most common and practical uses. 

1. Creating Texture

A quick YouTube search for “noise After Effects” will net you several tutorials for the most basic application of noise for textures, adding a bit of value to otherwise flat or single colored motion graphics elements.

Like many effects, this is something that can either be turned to 11 for a stylized look or applied as a subtle icing on the cake like the characters above.

The below GIF was achieved in essentially no time at all with fractal noise in After Effects. With some tweaking, you can generate stripes, blobs, swirls, and all kinds of looks from just one instance of noise.

2. Generating Quick and Dirty Dynamics

Noise’s strongest property is its procedural nature. Once you’ve created a noise pattern that you’re happy with, it can be recreated and evolved randomly without breaking the rules you set for it.

From there, it’s a matter of knowing which inputs you want to animate and you can really start having fun with the results. 

Shockwaves, smoke, clouds, nebulae, water — all of these dynamic occurrences can (to some degree) be mimicked through the use of noise in conjunction with other techniques. It’s important to note the limitations of this in comparison to either a full CG simulation or use of stock footage. The best case for it is usually supplementary. 

If you’re compositing a spooky cornfield with some of our atmospheric smoke and fog, for example, there are a lot of opportunities to fill in any gaps with well blended and softly feathered noise generated smoke. Or, if you just want to make lava as I did for the GIF above, you can do that too!

3. Creating Mattes and Maps

At its core, noise is a translation of data to value in an image. This simplicity and flexibility makes noise extremely useful for a variety of both mattes and maps. For alpha channels, noise can be used to create broken and uneven edges.

This can offer a huge advantage in comparison to simple feathers or gradients, especially when compositing elements with complex patterns. It would look unnatural if they were blended smoothly and predictably.

Below you can see how noise and some masks could be used to blend two elements in interesting ways.
Another common use of noise data is to drive various displacement maps. In After Effects, the two hit combo is fractal noise and turbulent displace. These tools can be a quick solution for distortion effects such as heat waves, mirages, and shock blasts.

These three simple noise tricks are just the tip of the iceberg for this incredible tool! Whether you’re in After Effects, Nuke, or even CG packages like Maya or Blender, always know in the back of your head that noise is available to you. 

As a concept, it’s one of the few gold standard tools that can be found in nearly all forms of digital art. Master it and know it well!             

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