> simulations

Field Fill

simulations/field-fill·v1.5.1

IN:3 OUT:3

SUMMARY

The Field Fill operator takes a grid POP whose Weight marks the space to fill. Seed particles move along the gradient of the distance to the unfilled space and clear the weight around them, and the operator outputs the filled field, the particle trails as line strips and a lookup result.

Seeds come from the Seed input or are scattered on the field's surface with Spawn From Density, and Continuous Simulation lets the weight grow back so the particles keep roaming. The Lookup input samples the filled field onto any geometry as weight or color, and the simulation runs as a feedback loop (Initialize, Start, Play).

PARAMETERS

PAGEField Fill

[+]Simulation Resolution	Simres	The resulting grid resolution (read-only).
[+]Simulation Size	Simsize	Size of the field volume, taken from the input (read-only).
[+]Simulation Center	Simcenter	Center of the field volume, taken from the input (read-only).
Display Field	Displayfield	Enable drawing the occupied voxels as points.
Display Seeds	Displayseeds	Display the particles.
Display Bounds	Displaybounds	Display the field box.
Weight Attribute	Weightinputattr	Float attribute of the input field marking the space to fill. 1 fills, 0 is empty.
Color Attribute	Colorinputattr	Color attribute of the field, carried into the filled output.
Time Scale	Timescale	Speed multiplier on the time step. 0 freezes and 2 doubles.
Time Step	Timestep	The time step per frame in seconds, 1 divided by the cook rate (read-only). Time Scale multiplies it.
Radius	Radius	Radius each particle clears per frame. Smaller values pack tighter.
Velocity Blur Passes	Blurpasses	Number of Gaussian blur passes on the guiding velocity per frame, for smoother, rounder paths. 0 disables the blur.
Blur Sigma	Blursigma	Sigma of the velocity blur, in cells.
Continuous Simulation	Continuoussim	Keep running after the field is filled. Cleared weight regrows by Retention each frame.
Retention	Retention	Fraction of the original weight that regrows per 1/60 second in Continuous Simulation (the same per second at any frame rate).
Stop Threshold	Stopthreshold	Stop the particles once the remaining total weight drops below this value.
Weight Output Attribute	Weightoutputattr	Name of the attribute holding the remaining weight on the Field output.
Inverted Weight Output Attribute	Invweightoutputattr	Name of the filled attribute on the Field output: 1 minus the remaining weight, masked by the input weight.
Color Output Attribute	Coloroutputattr	Name of the color attribute on the Field output: the input color multiplied by the remaining weight.
Initialize	Initializepulse	Initializes the POP from its input and parameters. The particles start at their seeds.
Start	Startpulse	Start the simulation from the initialized state.
Play	Play	Pause or play the feedback loop.
Step	Steppulse	Advance the simulation by one frame while paused.

PAGESeed

Spawn From Density	Spawn	Spawn the seeds on a surface built where the Dist/Weight Attribute crosses Threshold, instead of from the seed input.
Dist/Weight Attribute	Disweighttattr	Attribute of the field the spawn surface is built from: a signed distance (Dist) or a density (Weight).
Threshold	Threshold	Value of the Dist/Weight Attribute where the spawn surface is built: 0 for a signed distance, between 0 and 1 for a weight.
Seed	Seed	Numerical value that initializes the randomization.
[+]Method	Method	How to sprinkle points: on primitives like triangles/quads, or inside closed volumes formed by primitives like triangles/quads.
Number of Points	Numpoints	Sets the number of particles to spawn.
Attempts per Point	Attemptsperpoint	For volume sprinkle, the number of attempts to try to get a point inside the mesh.
[+]Ray Direction Mode	Raydirmode	To determine if point is inside or outside, cast rays in random direction or in constant direction.
[+]Ray Direction	Raydir	Constant direction to cast rays to determine if candidate point is inside or outside.
[+]Hardware Ray Tracing	Hwraytracing	Selects mode for Hardware Ray Tracing if supported. Used by the Volume scatter inside test, Windows only.

PAGETrails

Enable Trails	Enabletrails	Enable recording each particle's path as a line strip on output 2.
Length	Length	Length of the trails in 1/60 second steps: the trails cover Length / 60 seconds at any frame rate.
Line Smooth	Linesmooth	Enable smoothing the trails.
[+]Filter Type	Filtertype	Determines the smoothing kernel type: Gaussian or Box.
Edge Distance	Filterdist	Size of the smoothing kernel along the line.
Effect	Effect	Determines the amount of smoothing applied, blending from the raw result at 0 to the smoothed result at 1.
End Points Fixed	Endpointsfixed	Keep the end points of the trails fixed while smoothing.

PAGELookup

Voxel Centered Sampling Location	Voxelcentered	Sample at voxel centers, a half-cell offset, per axis.
Cyclic Index	Cyclic	Wrap the lookup on this axis.
[+]Input Extend Mode	Inputextend	What happens when the lookup falls outside the field: Hold, Zero, Repeat or Mirror.
Interpolate	Interpolate	When on, values are interpolated between samples. When off, the nearest sample is used.
Margin	Margin	Padding added to the field bounds before the lookup.
[+]Translate	T	Shift the lookup in field UVW, where 0 to 1 spans the field.
Rotate	R	Rotate the lookup around the pivot. Angles are given in degrees.
[+]Scale	S	Scale the lookup about the pivot, in field UVW.
[+]Pivot	P	The pivot point of the lookup scale, in field UVW.
Debug Lookup Weight	Debuglookupweight	Write the sampled weight as the color of the Lookup Output.

PAGECommon

Free Extra GPU Memory

Freeextragpumem

Free memory that has accumulated when output memory has grown and shrunk.

INPUTS

Input 0 POP - Field to Fill

Input 1 POP - Seed

Input 2 POP - Lookup Input

OUTPUTS

Output 0 POP - Field

Output 1 POP - Trails

Output 2 POP - Lookup Output