Pixelblaze Pattern: RGB-XYZ 3D Sweep

The success of a static test pattern in 3D space is encouraging, but it’s still in the realm of something fairly easy to replicate with a simple microcontroller. We have barely tapped into the power of a Pixelblaze controller. Using the pixel mapper is fun, but it’s the animation engine that makes a Pixelblaze exciting.

Resisting an urge to go wild, this next step is only a small incremental step from the static pattern. Again it is a test of all three coordinate axis, and again I will map RGB to XYZ in that order. The difference this time is that each axis and their positive direction will be shown with an animation, and since I’m starting to play in the time domain, each axis will get their own time to shine with an animated band of illuminated pixels.

The band needs to be wide enough to span several pixels, for a smooth handoff between one to the next. If the band covers less than two pixels, it would look more like a collection of blinking LEDs which might be cool but the objective is to convey motion.

Since the coordinate space is passed into render3D(index,x,y,z) in the range of 0 to 1, the naive first approach is to animate from 0 to 1. This turned out to look strange, because the animated band would pop into existance across several LEDs, reach the opposite end, and blink out abruptly. The solution to this problem is to increase the range of sweep so that our band (mathematically) starts off the display space before entering the stage, and exits the stage gracefully out the other end.

But that alone didn’t give us a pleasing sweep. I realized the band is too harsh so an additional blend was required: instead of LEDs turning on and off, there will be a ramp-up and a ramp-down for a smoother edge to the band. This looks better but might get in the way of diagnosing pixel alignment issues, so I left both as option in the code that can be switched back and forth with the style variable.

Code for this pattern is avilable on Github and also shared on public Pixelblaze pattern database as “RGB-XYZ 3D Sweep”

What’s next? Maybe add some interactivity by introducing some sensors into the mix.

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