Skip to content

Effects and chasers

The problem

Lighting often needs things that keep moving: a slow colour wash rolling across the rig, moving heads circling, dimmers pulsing to the beat, a red-blue-red-blue flicker. You could program that as a long list of cues, one per step, but:

  • you'd need dozens of cues for one smooth circle
  • the speed would be fixed in the cue times, while every DJ plays at a different tempo
  • spreading it across fixtures ("each light a bit later than its neighbour") would multiply the work again

grandMA2 has two tools for anything that loops: effects and chasers. They solve the problem in very different ways.

Effects: a modulation of attributes

An effect doesn't store steps. It describes a movement: an attribute swinging between a low and a high value following a form (sine, ramp, step …), at a speed. "Dimmer from 0 to 100 as a sine at 60 BPM" is one effect, whether it runs on 2 fixtures or 200.

An effect is spread across the selection:

  • Phase offsets each fixture's position in the cycle. Spread the phase from 0° to 360° along the selection and you get a wave running through the rig. The order comes from your selection or group (see Selection and groups).
  • Width says how much of the cycle each fixture is "on". Together with MAtricks (blocks, groups, wings) this builds chases, waves and alternating patterns without any steps.
Selection order The same sine, phase spread 0°→360° Right now Fixture 1 phase 0° 21 Fixture 2 phase 72° 79 Fixture 3 phase 144° 98 Fixture 4 phase 216° 50 Fixture 5 phase 288° 2 now time (two effect cycles) the wave runs this way
One sine on five fixtures, phase spread along the selection. Each fixture runs the same curve a little later, so at any moment the levels form a wave.
Absolute vs. relative
An absolute effect moves between fixed low and high values. A relative effect adds its movement on top of the current value, which is what you want for position (circle around where the light is pointing).
Template vs. selective
A template effect works on any fixtures you select that have the attributes. A selective effect is tied to specific fixtures, like a selective preset.
Low and high can be presets
An effect between preset "Red" and preset "Blue" follows when the presets are updated. This is the same reference idea as in Presets.

Effects live in the effect pool, can be started from there, stored into cues like any other value (they are the effect layers in the sheets), or put on an executor of their own.

Movement effects on moving lights

Movement is where effects and presets meet. To keep movement working when the room or the hang changes, build it on position presets:

Relative effect around a position preset
Apply a position preset ("Centre", "DJ booth"), then a relative pan/tilt effect (circle, sweep). The manual notes that relative effects add their low and high values onto the actual value, and are "mainly used in pan and tilt". The preset is the centre, the effect is the shape around it. Store both in the cue: change the preset later and the movement moves with it.
Absolute effect between position presets
Set the effect's low and high values to presets ("Stage left" and "Stage right", or "Floor" and "Air"). The beams travel between the two positions, and follow when either preset is updated.
Relative effect circle around preset “DJ booth” DJ booth the preset is the centre, the effect is the shape around it Preset updated booth is further left tonight before update DJ booth Update the preset once: every cue with this circle follows Absolute effect low/high = two position presets Stage L Stage R beams travel between the presets and follow when either is updated position preset beam path of the effect (pan/tilt seen from the front)
Relative: the preset is the centre and the effect the shape around it, so updating the preset moves the movement. Absolute: the effect travels between two presets.

With the phase spread across an ordered group (or MAtricks wings for a mirrored fan), one movement effect turns into a wave, a ballyhoo or a symmetric fan across the whole rig.

Practice

For busking, a common setup is: position presets on buttons (where the beams point), relative movement effects on faders (how much they move, with the fader as effect size), all on one speed master. Position and movement can then be combined freely, and the effects follow the tempo.

To verify in onPC: check 8

Chasers: a looping sequence

A chaser is a sequence whose cues are played as steps in a loop. The cue timing is ignored; instead the chaser has its own speed (in BPM) and a step fade (how much of each step is spent fading: 0% snaps, 100% fades the whole time). You can run it forward, backward, bounce or random, endlessly or once.

Because each step is just a cue, a chaser can contain anything: complete looks, different fixtures in each step, positions plus colours plus gobos.

Which one when?

The manual's rule of thumb is short: chasers "whenever you need a loop with more than two steps. If you only need two steps, then use an effect."

Practice

A broader rule of thumb from practice:

You want Use
smooth, continuous movement (circles, sine dimmer, colour fade) effect
the same movement spread across many fixtures as a wave or fan effect with phase spread
a pattern of distinct looks, each step different (this look, then that one) chaser
a story that progresses once, with exact timing cues
to sync everything to the music either, on a shared speed master

Effects are usually the more flexible choice: one effect on a group adapts to any number of fixtures, while a chaser has to be re-programmed when the rig changes.

For a look that needs several tools at once (an effect plus presets plus MAtricks, or a chaser next to an effect executor), see Choosing the tool for a look.

Speed: keeping everything in time

Both effects and chasers can follow one of the 15 speed masters, one of which can follow the beat of the sound input. Put all your rhythmic material on the same speed master and one tap tempo (Learn) keeps everything in sync. Chasers also offer half/double speed and speed factors for "same beat, twice as fast". See Timing, and for the musical side (tap vs. BPM detection, factors per layer, SyncEffects for phase) Playing in time.

When it matters, and when not

  • Concerts and busking: effects and chasers on a shared speed master are central. Expect to spend real time on them.
  • Programmed routines (an intro, a live act's fixed set): occasional effects stored in the cues, such as a slow flicker under the intro; chasers less often.
  • Predefined effects in the effect pool are a good way to start. Apply, watch, then open the editor to see how they're built.

Sources