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DLA

simulations/dla·v1.5.1

IN:2 OUT:3

SUMMARY

The DLA operator spreads random walkers through a box, or on and inside the Geometry input, and lets them diffuse until they come within Attach Distance of the growing structure and stick to it. The points of the Seed input start the structure, and the operator outputs the structure as points, as lines from each point to its parent, and the walkers that are still diffusing.

Attach Distance sets how fine the branches are, while Attach Strength, Stick Probability and Noise Amplitude control how fast and how dense the growth is. Enable Life Cycle lets attached points die and respawn as walkers so branches decay and regrow, and the simulation runs as a feedback loop (Initialize, Start, Play) with a Walkers Target Feedback Loop POP for forces downstream.

PARAMETERS

PAGEDLA

Walkers Target Feedback Loop POP	Targetpop	A reference to a POP node downstream in the network whose data is retrieved one frame later. Only P is read back, as the walkers.
[+]Simulation Bounds	Simbounds	Sets the size of the box the walkers spawn in and stay inside, used when there is no Geometry input.
[+]Simulation Center	Simcenter	Sets the center of the simulation box.
Display Bounds	Displaybounds	Display the simulation box.
Display Random Walkers	Displayrandomwalkers	Display the walkers that are still diffusing, in red.
Display DLA Structure (Points)	Displaydlapoints	Display the structure as points on the first output.
Display DLA Structure (Lines)	Displaydlalines	Display the structure as lines from each point to its parent, on the second output.
Display Seeds	Displayseeds	Display the seeds (the Seed input's points) as spheres. Nothing is drawn while the Seed input is not connected.
Seeds Scale	Seedsscale	Sets the radius of the drawn seed spheres.
Max Number of Points	Maxpoints	Sets the number of walkers. The structure can grow by this many points plus the seeds.
Seed	Seed	Numerical value that initializes the randomization.
[+]Scatter Method	Method	How to sprinkle points: on primitives like triangles/quads, or inside closed volumes formed by primitives like triangles/quads.
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	Sets the constant direction of the rays that test whether a 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.
Max Search Distance	Maxsearchdist	Sets how far a walker looks for the structure. It is also the largest jump per step when nothing is in range.
Attach Distance	Attachdist	A walker within this distance of a structure point attaches to it. Smaller values give finer branches.
Attach Strength	Attachstrength	Sets the drift toward structure points in range, in units per second. 0 gives pure DLA, higher values grow faster and denser.
Stick Probability	Stickprob	Sets the chance per 1/60 second that a walker in reach attaches, the same at any frame rate. 1 is classic DLA, lower values grow denser.
Max Neighbors	Maxneighbors	Number of nearest structure points driving the attach drift, from 1 to 8.
Internal Noise	Internalnoise	When on, the walk's random vector (Rand) is generated here. When off, the input's Rand attribute drives the walk.
Noise Amplitude	Noiseamp	Sets the walk speed in units per second, the largest step a walker takes per frame.
Enable Life Cycle	Enablelifecycle	When on, walkers age: after their life span they die, wait the Respawn Delay and restart from their spawn position.
Life Span	Life	Life span of a structure point after it attaches, in seconds.
Life Variance (Fraction)	Lifevariance	Life Expectancy variation as fraction of life expectancy, added or removed at random per point.
Respawn Delay	Respawndelay	Sets the time in seconds a dead walker waits before it respawns.
Initialize	Initializepulse	Initializes the POP from its input and parameters. The input points become the seeds and the walkers start fresh.
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.

PAGECommon

Free Extra GPU Memory

Freeextragpumem

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

INPUTS

Input 0 POP - Seed

Input 1 POP - Geometry

OUTPUTS

Output 0 POP - DLA Structure (Points)

Output 1 POP - DLA Structure (Lines)

Output 2 POP - Random Walkers