Whether busking lighting for a live rock band where the drummer naturally ebbs and flows, triggering cues to a club DJ mixing tracks at fluctuating tempos, or executing precision theater cues against a fixed backing track, rhythmic cohesion is what separates amateur blinking lights from a professional light show. Unilighter features a unified, project-wide master clock architecture that keeps keyframe curves, step chases, procedural oscillators, and audio triggers tightly locked in musical sync.
🎛️ Master Tempo Controls in the Header
Positioned persistently in the top navigation bar, the tempo block provides instant, zero-latency access to the show timebase:
1. Numeric BPM Display
Displays the current project tempo with at most one decimal place (e.g. 120 BPM or 128.5 BPM). Calculations and saved values retain full precision. Clicking the number opens a direct numerical input to type an exact tempo value (e.g. 128.5).
2. TAP Tempo Button
The primary tool for live show busking. Tapping the button (or hitting a mapped keyboard shortcut / MIDI pad) continuously computes a rolling moving average of recent tap intervals. Within 3 to 4 taps, Unilighter locks smoothly onto the live tempo.
3. x2 and /2 Quick Multipliers
Instant half-time and double-time buttons. When a DJ transitions from a 70 BPM half-time hip-hop groove into a 140 BPM dubstep drop, clicking x2 doubles the show speed instantly while keeping the existing downbeat phase intact.
4. Beat Reset Button (⟲)
Resynchronizes the master downbeat to the current exact millisecond without changing the tempo value. If a live drummer drops a beat or comes in off-phrase after a drum fill, a single hit on Beat Reset pulls all running animations back into step instantly.
⏱️ How Engine Subsystems Synchronize
1. Keyframe Animation Timelines
- Elapsed-Time Playback: The playback position follows actual elapsed time rather than the number of processed frames. At 120 BPM and 1x, 16 beats last 8 seconds after the initial next-beat launch wait. Lower frame rates or a busy visualizer can reduce update smoothness without stretching the timeline.
- Continuous Loops: A delayed update retains the portion of time already elapsed into the next cycle. Both the runtime animation and editor preview preserve this remainder.
- Beats vs. Seconds Mode: Timelines support two distinct time modes: absolute Seconds or musical Beats.
- Proportional Scaling: In Beat mode, keyframes are placed on musical bars and subdivisions (
1.0,1.25,2.0). When the master BPM changes, the timeline expands or contracts proportionally—your lighting cues remain locked to the music without manual re-keyframing. - Track Multipliers: Each keyframe animation includes an independent multiplier from
/8through8x, allowing rapid accents to run far above the project tempo while slow ambient color washes stretch across several beats. - Phase-Preserving Pause: Pausing an animation freezes its exact beat offset, ensuring that resuming playback retains musical phase.
2. Step Chases
Each step's duration is defined in musical beat fractions (1/1, 1/2, 1/4, 1/8, 1/16). A 4-step chase set to 1/4 executes a complete cycle every musical bar.
3. Node Graph Oscillators & Wave Generators
In Oscillator Nodes, toggling BPM Sync binds wave oscillation frequencies directly to master tempo subdivisions, producing sweeping moving head ballyhoos and dimmer breathing effects that breathe in time with the song.
4. Autonomous Tempo Tracking with BpmNode
With a BPM Node connected to a live Audio Input, enabling Control tempo lets a confidently tracked musical grid gradually steer both master tempo and phase. Timestamped audio analysis runs independently of graph updates. Tempo changes and phase alignment use gradual speed adjustments so running beat animations retain a continuous position.
Continuous audio corrections preserve step-animation selection, hold timers, playback direction and running fades. Steps configured to advance on beats continue following the master clock, while timed holds keep their configured duration.
Beat-phase estimates are smoothed, and a large change must remain consistent for two beats before the clock follows it. This reduces tempo excursions caused by brief subdivision changes while still allowing gradual alignment to a new song. Master tempo can temporarily differ from the detected tempo during alignment; see BPM Node for tracking states and limitations.
The Response knob trades early response against stronger confirmation. Its default 25% · Careful waits for a consistent grid. Fast can follow a Provisional tempo from early intervals while its beat phase remains unconfirmed; it may be corrected as more evidence arrives. The node also distinguishes Acquiring, Locked, Holdover and Lost. Weak or missing evidence pauses phase corrections while the clock continues at its last adopted tempo. Manual TAP or a manual tempo edit takes ownership away from the audio node.
At 0–33% Response, the node holds the accepted tempo and requires fresh confirmation before replacing it; small estimate fluctuations below 0.5 BPM do not change that target.
Sync beat phase is enabled by default. Turn it off on the BPM Node to follow tempo without aligning the clock to audio beats. With Stable/Careful, the master then settles to the held tempo until a new one is confirmed. Small estimation errors can gradually cause beat drift in this mode. Switching the setting preserves tracking history and animation position. With phase synchronization enabled, temporary BPM movement remains part of beat alignment even while the accepted tempo is held.
Use Clock for musical pulses and Transient for detected audio attacks. Old projects retain their mixed Trigger output for compatibility. Automatic synchronization is relative to the captured audio: it does not compensate for external speaker or fixture latency, identify bar downbeats, or guarantee a lock on rhythmically ambiguous material.
🎮 Tactile Hardware Mapping
Physical controllers can be bound to the master tempo system using Assign Mode:
- Tactile TAP Button: Map a physical rubber drum pad or momentary button to TAP and another to Beat Reset.
- Rotary BPM Encoder: Assign an endless rotary dial to smoothly nudge or sweep BPM live during performance.
Note
Unilighter's MIDI synchronization is strictly inbound from hardware controllers to the console.
Read more in the Animations Reference Manual and the Assign Mode & Controller Mapping Guide.
Computer Sleep
In an updated Unilighter Desktop shell, playback time freezes during system sleep by default and resumes from the same position after waking. Open Advanced settings to include sleep in playback time instead. A manually paused animation remains paused in either mode. Minimizing the window or locking the screen does not itself pause playback.