Tutorial - Moving Head Patterns

[Mathieu]

Here's a little sample project showing a few movement patterns to help you get started with moving heads.

** Make sure you're running Lightjams version 426 or higher **

There are 4 moving heads (Mac 101) named A, B, C and D. The things to know before starting:

- Some specific patterns like a circle cannot be formed if the head is pointing straight up or down (depending if the moving head is on the floor or ceiling). Ideally, hang your moving heads horizontally.

- The closer to extremes the moving head is pointing, the less accurate the pattern will be. So try to keep the tilt between 80 and 20 degrees.  

- The min&max for the pan and tilt need to be set to define the area of the pattern. Most moving heads have a pan of 540 degrees but only about a 120 degrees range is used to create geometric patterns. The whole 540 degrees range is useful when creating more organic patterns.

- Good starting values for the min&max are: Pan min=70, max=110, Tilt min=20, max=60. Feel free offsetting the pan range to point in the direction you want. TIP: right-click in the middle section of the range selector control to offset the min&max together.

- Most moving heads are relatively slow so first try the pattern at a low speed and gradually speed it up until you see the moving head lagging behind.

Now back to the sample project. You can go in the pan/tilt grid and open the monitor (ctrl-m). As of version 424, you can also select the pan and tilt attributes of a fixture on a grid and see the pattern on the right.

Here are the patterns for the 4 moving heads:

A) Circle

The range of the pan and tilt (the difference between max and min) are equal, giving the circle pattern. In this case,the range is 40 degrees. The source controlling the pan is a cosine and the one controlling the tilt is a sinus.

TIP: when modifying a source's formula, to make sure the pan and tilt are still in sync, click the reset time button at the top right of the grid.

B) Ellipse

By modifying the range of the pan or tilt and not having equal ranges, you get an ellipse. In this case, the range for the pan is 80 degrees and the range for the tilt is 40 degrees. The result is an horizontal ellipse.

C) Figure-8

A cosine twice as fast to control the pan gives the figure-8. In the sample project, the cosine for the pan is 1.5 seconds and the sine for the tilt is 3 seconds. 

One funny thing to experiment with is to use the formulas for the circle and move the tilt around 90 degrees (pointing straight down). This also gives you a figure-8.

D) Diamond

The triangle function comes handy here. For the tilt, configure the source's power with formula: triangle(3). Then for the pan, we need the same triangle but shifted (delayed) by 1/4 of a cycle (25%). Here's one way of doing it. The formula for the source controlling the pan is: map.triangle(sawtooth(3)+25). The sawtooth goes from 0% to 100% in 3 seconds. But then we offset it by 25% so that it goes from 25% to 125%. The map.triangle function then generates our shifted triangle.

You could also use the source's delay function and control both the pan and tilt with the same source but move the pan away in order to delay it. It's a less precise way but may be more fun to experiment.

Enjoy!