head doesnt move in circle but rather a figure 8
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mcallegari79
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A little X offset, makes the pattern rotate.
Branch for testing: https://github.com/plugz/qlcplus/tree/efxpreview
(This works only for a 540⁰ pan range fixture)
That makes sense to me!
I would like to add a comment which might be helpful. I have seen many questions on various forums about moving lights in a circle. I think what many people are wondering (as I did once) is how can I get them going around and around (like the lights on a police car do). Say you start your light at 0 pan and 0 tilt (which probably means it is pointing straight out at a right angle to the fixture if it is hanging or sitting on its base). Don't move the tilt, but send it a signal to go to DMX 255 and it will pan all the way around and probably another half circle or so again (depending on what its pan range is, most are around 500-540 degrees). Now here is the rub. What everyone wants is to have it keep on going. "Hmmm, what if I send it a 0 now." What the light now does is go backward in the opposite direction back to 0. The 0-255 DMX range (or 0-64000 if you are using fine grain control) maps to the 540 degree (or so) circular turning range, but the light will ALWAYS MOVE IN THE DIRECTION of the difference between the current value and the new value. If you are going from 0-255 (0 degrees to 540 degrees) and it move clockwise, if you now go back to 0 it will move counterclockwise.
"But what if I want it to keep going round and round in the same direction?"
Sorry, most moving lights can't do this. And the reason is actually physical. The lights have connections between the lighting controller mounted in the base and the light head itself. These are usually wires and if the light kept moving in the same direction, these wires would get all twisted until they would simply stop the light or break. The light MUST go back in the opposite direction.
The only way a light could actually keep going in the same direction endlessly is if it used moving contact strips between the head and the base so that there were no wires to wind up. However, that isn't going to be found on a low-end lighting device for sure. Another option is a moving mirror light where the light stays fixed and only a mirror turns and the motor that turns it is also stationary and there are no wires between the base and the mirror.
So the circular paths that are traversed in various systems are usually really figure eights (in which the pan path alternates with each cycle) but tilted in a way that sort of looks like a circle. At least that's the best that I can describe it.
Jon