Morf_tool

Houdini Digital Asset (morf_tool) for handling transitions between formations in a drone show timeline. Controls timing, spatial falloff, inflation/deflation effects, and transition bias masks.

HDA: houdinitools/hda/morf_tool.hda

Parameters

Time

ParameterTypeDefaultDescription
Start Frame Start_FrameInteger1Frame on which drones leave the first figure (input 1).
DurationInteger100Length of the transition in frames: drones arrive at the second figure (input 2) on Start Frame + Duration.
Time Interpolate Time_InterpolateFloat ramp—How far drones have moved (vertical axis) over the transition time (horizontal axis). A straight line moves them evenly; flatten its ends to ease in and out.

Falloff

ParameterTypeDefaultDescription
Falloff On Falloff_OnMenuOffStart drones at different times by their distance from Falloff Position, so the transition runs across the formation as a wave. With falloff each drone flies in half of Duration, so it moves twice as fast as without it.
Reverse revMenuonOn: drones nearest to Falloff Position move first. Off: the farthest move first.
Falloff Position sortfromFloat ×30, 0, 0Point the falloff wave is measured from, in scene coordinates. Distances are taken to the drones of the first figure. Hidden when Falloff_On != 1
Falloff Curve Falloff_CurveFloat ramp—Maps the distance from Falloff Position (horizontal axis: 0 nearest, 1 farthest) to the start delay (vertical axis: 0 starts at once, 1 starts halfway through the transition). Hidden when Falloff_On != 1

Inflation

ParameterTypeDefaultDescription
Inflation On inflationonToggleOffPush drones outward from the center of the first figure during the transition, most in its first half, so the formation swells instead of passing through itself.
Inflation Scale inflationscaleFloat1Strength of the inflation push: at 1 a drone is moved up to about 1.2 m. Hidden when inflationon != 1
Deflation On deflationonToggleOffPush drones outward from the center of the second figure during the transition, most in its second half, so the formation shrinks into place.
Deflation Scale deflationscaleFloat2Strength of the deflation push: at 1 a drone is moved up to about 1.2 m. Hidden when deflationon != 1

Transition bias mask

ParameterTypeDefaultDescription
Enable transition bias mask transition_bias_maskToggleOffWrite each drone's transition progress to a point attribute: 0 still at the first figure, 1 arrived at the second. Use it to drive other effects, such as color, by the transition.
set custom name transition_mask_nameString—Name of the point attribute for the transition progress. Empty writes it to bias. Hidden when transition_bias_mask == 0

Usage

  1. Set timing — Configure Start Frame and Duration for the transition
  2. Adjust easing — Use Time Interpolate ramp for ease-in/ease-out
  3. Spatial falloff — Enable Falloff On and position the falloff origin to make the transition propagate across the formation (e.g., left-to-right or center-out)
  4. Inflation/Deflation — Optionally enable Inflation On or Deflation On to add scale-based movement from the origin during the transition
  5. Per-point bias — Enable transition bias mask to control individual drone transition timing via a custom attribute

Video tutorials

Dronatello Course #08 — Morphing Between Shapes: An IntroductionMorphing is one of the most widely used animation techniques in drone shows. We set up a Morph node between two text variations with matching point counts and explore how its parameters shape the transition.
Dronatello Course #22 — Advanced Transitions Using an Intermediate FormationA plain cut from static text to static coral is boring. We add an intermediate bubble formation using linked reference copies of the Morph node, creating a smooth, thematic transition that fits the underwater story.