09 Feb 2019

This article will take about 3 minutes to read.

Few days ago, I was chatting with our design team, and we were wondering how hard would be to create a fake audio spectrum (that mimics human speech) and visualize it. I immediately said it should be easy, and that I will play with it over the weekend. Of course, I didn’t wait for the weekend, but wrote it the same evening. It was fairly straightforward, but it had few gotchas.


Before you start playing with the checkboxes I advise you to read the rest of this post.


My initial idea was to analyze couple of audio files to extract the Try disabling all checkboxes but “static”. for the spectrum. Then combine it with the data from this great post about language pitch. At the end, I ended up tweaking values to make it “look better”, based only on my personal feel.

Only thing left was to multiple the values I got with the Enable “random” and “static” checkboxes and disable the “perlin” one to see how it looks. It kinda works, but it feel too random.

Perlin noise

But before I started, I asked my colleagues for ideas, and I got some great feedback. One of the suggestions was to use Perlin noise. I’ve never heard of it, so I did some reading.

Perlin Noise is a technique used to produce natural appearing textures on computer generated surfaces for motion picture visual effects.

Ken Perlin was frustrated by machine-like look of computer graphics at the time, and created a gradient noise algorithm. It is basically a pseudo-random generator which outputs more Disable “random” and play with the other two checkboxes to see how it feels. .

That seemed like a great way to improve my random only solution.

There are multiple JavaScript implementations, but I ended using this one as it was really simple and I didn’t need 2D or 3D noise.

Putting everything together

Now when I had everything I needed, it was easy to write the actual code. Working demo was done really quickly. Then I started playing with values and tweaking them. Finally I was satisfied with the result. It still feels a little bit too smooth and unnatural. But I didn’t mind it that much, I left it as something that can be improved, along with different speed for jumps and drops.

To animate things I ended up using CSS transforms plus flexbox, as it was the easiest way I could think of. Using canvas probably could probably improve performance, but this was a proof of concept and I didn’t bother with it.

Code can be found on Codepen. Have fun!

We probably won’t use this one on the real project, but it’s about the journey, not the destination. I had a lot of fun and I learned new things. And that is the main reason I enjoy research and proof of concepts so much.