> modifiers

Move Along Curve

modifiers/move-along-curve·v1.3.0

IN:2 OUT:1

SUMMARY

The Move Along Curve attaches instances to a curve and animates them along the path using Line Strip POP. It works in two phases similar to Move Along Mesh: first, attaches instances to the curve based on proximity, distribution, or attributes; second, moves instances along the path either procedurally or through a solver.

There are several presets available to set up your instances to move as a group or to distribute themselves evenly along the path. The operator includes options for wrapping from the end of the path to the start, enabling easy looping motion.

The Attach step allows you to attach instances based on their proximity to the curve or based on an even distribution. You can even attach to multiple curves per-instance via a point attribute. The Offset controls determine how much of the original distance between each instance's starting position and the attachment position is maintained.

The Animation step allows procedurally moving instances along the curve based on the Goal parameter, or pushing the instances per timestep in a solver.

PARAMETERS

PAGEMove Along Curve

Group	Group	If there are input groups, specifying a group name in this field will cause this POPX to act only upon the group specified.
Curve to Attach To	Curve	Reference to a POP for the curve to attach instances to when no second input is connected.
Display Curve	Displaycurve	Visualizes the curve in the viewport.
[+]Display Color	Displaycolor	Color for curve visualization when Display Curve is enabled.
[+]Mode	Mode	Switches between Simple mode (procedural animation) and Solver mode (per-timestep solver).
Initialize	Initializepulse	Resets the simulation state to initial conditions.
Start	Startpulse	Begins the simulation from the current state.
Play	Play	Toggles simulation playback on or off when in Solver mode.
Step	Steppulse	Advances the simulation by one frame when in Solver mode.

PAGEAttach

Lock to Curve	Locktocurve	Locks the initial attachment positions so they don't need to be recalculated every frame, improving performance.
Reattach to Curve	Reattachtocurve	Recomputes attachment points for all instances.
[+]Curve Select Mode	Curveselectmode	Determines how to select which curve primitive to attach to.
Primitive Index	Primindex	Specifies which primitive index to attach to when Curve Select Mode is set to Primitive Index.
[+]Attach Method	Attachmethod	Determines how instances are attached to the selected curve: Nearest Point, Distribute evenly, or use an Attribute.
Search Distance	Searchdistance	Maximum distance for finding nearest attachment points when using Nearest Point attach method.
Attach Attribute	Attachattr	Specifies which attribute to use for determining attachment positions when Attach Method is set to Attribute.
Snap Centroid to Curve Start	Snaptocentroid	Moves the centroid of all instances to the start of the curve before attaching.
Do Orient Snap	Doorientsnap	Applies orientation alignment when snapping centroid to curve start.
[+]Normal Axis	Normalaxis	Defines the normal axis for orientation snapping.
[+]Up Axis	Upaxis	Defines the up axis for orientation snapping.
Maintain Offset	Maintainoffset	Blend amount for maintaining the original offset distance from the curve.
Open Offset Ramp Editor	Openoffsetrampeditor	Opens the internal offset ramp editor for customizing offset behavior along the curve.
Reset Offset Ramp	Resetoffsetramp	Resets the offset ramp to default values.
Custom Offset TOP	Customoffsettop	Reference to an external TOP for offset control. When specified, overrides the internal ramp editor.
Maintain Orient Offset	Maintainorientoffset	Blend amount between the original orientation and the curve orientation.
Open Orient Offset Ramp Editor	Openorientoffsetrampeditor	Opens the internal orientation offset ramp editor.
Reset Orient Offset Ramp	Resetorientoffsetramp	Resets the orientation offset ramp to default values.
Custom Orient TOP	Customorienttop	Reference to an external TOP for orientation offset. When specified, overrides the internal ramp editor.
Visualize Offset	Visualizeoffset	Displays lines showing the offset between instances and their attachment points.
Fetch Offsets Lines	Fetchoffsetslines	Creates a select POP with the selected offsets lines of the instances for visualization.
Reorient Input Curve	Reorientinputcurve	Enables reorientation of the input curve for better tangent and normal calculation.
Invert Tangent	Inverttangent	Reverses the tangent direction of the curve by 180 degrees.
Custom First Tangent	Customfirsttangent	Enables specification of a custom tangent vector at the start of the curve.
[+]First Tangent	Firsttangent	Custom tangent vector for the first point of the curve.
Twist Curve Amount	Twistcurveamount	Amount of twist to apply to the curve orientation in degrees.
Open Twist Curve Ramp Editor	Opentwistcurverampeditor	Opens the internal twist ramp editor for modulating twist along the curve.
Reset Twist Curve Ramp	Resettwistcurveramp	Resets the twist ramp to default values.
Custom Twist Curve TOP	Customtwistcurvetop	Reference to an external TOP for twist control. When specified, overrides the internal ramp editor.
Twist by Attribute	Twistbyattribute	Enables twist control via a point attribute instead of the ramp or TOP.
Twist Attribute	Twistattr	Name of the point attribute to use for twist values when Twist by Attribute is enabled.
[+]Resample Method	Resamplemethod	Line strip resample method.
Divisions	Resampledivs	The number of divisions.
Max Distance	Resamplemaxdist	Maximum distance between points.
Maximum Number of Vertices	Maxverts	Sets the number of vertices to be allocated.
Max Tries for Binary Search	Maxtries	Max number of iterations for binary search when linearly resampling.

PAGEAnimate

Do Falloff	Dofalloff	Enables falloff-based modulation of animation effects.
Falloff Affects Speed	Affectspeed	Allows falloff values to modulate instance movement speed.
Falloff Affects Rotation	Affectrot	Allows falloff values to modulate instance rotation alignment.
Falloff Attribute	Falloffattr	Specifies which attribute to use for falloff values that modulate animation intensity.
[+]Goal Type	Goaltype	Determines how goal position is calculated: Goal U (parametric) or Arc Length (distance-based).
Goal	Goal	Target position along the curve for procedural animation in Simple mode. 0 is the start, 1 is the end of the curve.
Speed	Speed	Global speed multiplier for instance movement along the curve in Solver mode.
Random Speed	Randomspeed	Amount of random variation applied to each instance's speed.
Seed	Seedspeed	Random seed value for speed randomization.
Reverse	Reverse	Reverses the direction of movement along the curve.
Align to Curve	Aligntocurve	Aligns instance orientation to follow the curve tangent direction.
Wrap	Wrap	Enables wrapping from the end of the curve back to the start for continuous looping motion.
Output Goal Attributes	Outputgoalattrs	Outputs GoalU and CurveIndex attributes.
Twist Amount	Twistamount	Additional twist rotation applied during animation in degrees.
Open Twist Ramp Editor	Opentwistrampeditor	Opens the internal twist ramp editor for animation twist modulation.
Reset Twist Ramp	Resettwistramp	Resets the animation twist ramp to default values.
Custom Twist TOP	Customtwisttop	Reference to an external TOP for animation twist control. When specified, overrides the internal ramp editor.
Scale by Goal	Scalebygoal	Enables scale modulation based on goal position along the curve.
[+]Remap Scale	Remapscale	Remaps the output scale values from the ramp to this range.
Open Scale Ramp Editor	Openscalerampeditor	Opens the internal scale ramp editor for creating custom scale curves based on goal position.
Reset Scale Ramp	Resetscaleramp	Resets the scale ramp to default values.
Custom Scale TOP	Customscaletop	Reference to an external TOP for scale control. When specified, overrides the internal ramp editor.
Accelerate by Goal	Acceleratebygoal	Enables acceleration modulation based on goal position along the curve.
Open Acceleration Ramp Editor	Openaccrampeditor	Opens the internal acceleration ramp editor for modulating speed along the curve.
Reset Acceleration Ramp	Resetaccramp	Resets the acceleration ramp to default values.
Custom Acceleration TOP	Customacctop	Reference to an external TOP for acceleration control. When specified, overrides the internal ramp editor.

PAGECommon

Bypass	Bypass	Pass through the first input to the output unchanged.
Free Extra GPU Memory	Freeextragpumem	Free memory that has accumulated when output memory has grown and shrunk.
Render Primitives	Renderprimitives	Toggles rendering of POPX Geometry or shows it as point instances only.
Convert to Point Primitives	Converttoptprim	Converts points to primitive points when Render Primitives is toggled off.
SRT / RST	Srtrst	Sets the transform order when using POPX Geometry as built-in TouchDesigner instances.

INPUTS

Input 0 POP – POPX/POP Geometry

Input 1 POP – Curve to Attach To

OUTPUTS

Output 0 POP – POPX_out1