IR5 Interactive Piece

March 5th, 2013 by Keith Peters

Introduction by Rebecca Allen:

We are creating a new website that will be launching at the end of March. Working on our own site is always an exciting process and one that is challenging as well. Our goal was to do the following with the new site:

1. Make it memorable!
2. Create a unique and fun interactive experience that captures our brand.
3. Display quickly and beautifully no matter what size device.
4. Communicate our mission and what we do clearly.

Today, we are going to give a sneak peak into #2. Keith Peters will walk you through the steps he took to create this interactive experience. Keith, take it from here!


As part of Infrared5’s new web site design, I was asked to create an interactive piece for the main page. The mock ups called for the design that has been our trademark since day one – an abstract space made of random isometric planes and lines. This is the design that is on our letterhead, business cards, and previous versions of our site.
I was given free range to come up with something interactive based on that design. One idea floated was to have the planes connect  with the lines and rotate around in the space. I decided to go with this concept. I realized that the idea was a bit odd once I got down to coding it. I mean, isometry itself is a form of 3D projection, and we also wanted to move the planes around in a 3D space with actual perspective. It could become quite a mess if done wrong. Specifically, in an isometric system the angles do not change and objects do not change size with distance. But I forged ahead anyway to see what could be done that might look decent.
The first thing I did was just get a 3D system of rotating particles. This was something I’d done and written about before, so was relatively straightforward. As you click and drag the mouse vertically the particles rotate around the x-axis, changing their y and z coordinates. When you drag on horizontally they rotate around the y-axis, changing on x and z.

Next step was to change the particles into isometric planes. I started out with true isometric projection, meaning the angles representing each axis are each 120 degrees apart. I soon switched over to dimetric projection, which has two angles at approximately 116 degrees and the third at about 127.

This has several advantages. First, it’s easier to calculate sizes of objects as the x-axis is simply twice the size of the y-axis. This also results in smoother lines with less antialiasing.

There are three different shapes I needed to draw: a panel facing left, one facing right, and a floor/ceiling panel.

As these would be animating, I didn’t want to have to redraw them on each frame using the canvas drawing API. So I made a panel object that creates a small canvas and draws a single panel to it with a random width and height. The program can then blit each one of these mini panel canvases to the main canvas on each frame. Each panel also got its own random gray shade and the result was something like this:

Now as I said earlier, when you move things around in a 3d space, they are supposed to grow larger or smaller depending on the distance from the camera. But in isometric/dimetric projection this is not the case. So we’re really mixing two forms of perspective. Having the panels scale as they went into the distance didn’t look right at all. Having them remain unchanged wasn’t exactly correct either but gave an odd trippy feel to the piece that I actually like a lot. So that’s how I left it. Also, to mix things up a bit, I made some of the panels fixed in space and not rotating. This comes up to about one in ten of the panels being stationary.

Next was the lines. When creating the panels, I made it so that some – but not all – of the panels connect to one other panel with a line. About 40 percent of the time a connection is made. This seemed to give the right density of lines on screen. Here’s what that looked like initially:

Pretty ugly because the lines go directly from one corner of a panel to one corner of another, breaking the isometric/dimetric space. They just look random and chaotic. To solve that I forced the lines to follow the same dimetric angles as the planes. This looked a million times better.

In order to add a bit more interaction, I added a few functions to allow users to add and remove planes and to assign various color schemes to the planes (or return to grayscale). For the colors, rather than just use a random color for each plane, which would be a bit chaotic, I found an HSV to RGB algorithm. Taking an initial hue, I generate a different color for each panel by randomly varying its hue and saturation. This gives a more cohesive look no matter what hue is chosen.

The way the colors work is by redrawing each of the individual panel canvases with the same parameters, but the newly chosen color. Again, this makes it so it only has to happen a single time and the panels can then be blitted to the main canvas on each frame.

All in all, this was a fun project that I’m glad I had the chance to work on.


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