Surge XT's 16-step sequencer can retrigger envelopes per-step and shape transitions with the Deform control

When an LFO slot is set to Step Seq shape, it becomes a 16-step sequencer whose steps draw a modulation curve. The two blue markers define loop start/end points within the steps. A Deform control at 0% outputs the steps as drawn; negative values create sharp spiky transitions; positive values smooth steps toward curves. Voice LFOs have an extra retrigger lane above the steps: filling a rectangle triggers both AEG and FEG at that step; half-filling (left) triggers only the filter envelope; half-filling (right) triggers only the amplitude envelope. This lets you create rhythmic envelope-retrigger patterns driven by the sequencer without MIDI note data. Steps can be shift-clicked to quantize to pitch degrees for microtonal sequencing.

Examples

Draw a 4-step pattern, fill retrigger at steps 1 and 3 to create a double-hit AEG retrigger, then add positive Deform to smooth the amplitude transitions.

Assessment

Describe what the Deform slider does to step sequencer output at 0%, at maximum negative, and at maximum positive. Then explain how to make only the filter envelope retrigger at a specific step.