# Particle Fluid Solver dynamics node

Evolves an object as a particle fluid object.

The Particle Fluid Solver DOP evolves an object dynamically as a particle fluid.

## Changing from Metre Kilogram Second(MKS) to Centimetre Kilogram Second(CKS)

MKS is a physical system of units that expresses any given measurement using fundamental units of the metre, kilogram, and/or second. Unfortunately, the particle fluid object/solver does not expose the correct units to update its defaults so it does not change automatically. Going from MKS to CKS, you need to manually adjust the offending parms. The value given is the result of converting to CKS, the value in the parentheses is the scale factor used:

• Particle Separation: `10` (* 100)

• Rest Density: `1e-3` (/ 1003)

• Size: `100 x 100`

• Velocity: `100,0,0`

• Gas Constant: `0.025` (* 100 and / 1003)

• Viscosity: `0` (*10)

• `981` (* 100)

When converted to CKS, all new gravity nodes will have this proper value

The `* 100` makes the meter measures become centimetre measures.

The `/ (100*100*100)` is necessary because density measures kg/m3 and we are now measuring the denominator in centimetres.

Gas Constant is a force, so like Gravity, is `* 100`. However, the particle fluid solver applies forces to the density, not to the mass, so while our mass is the same (since kg == kg), our density isn’t, so the 1003 factor shows up again.

If you want CGS (centimetre grams seconds), rest density should be 1, the gas constant 25, and viscosity increased by a factor of 100 compared to the MKS system.

## Substeps

Min Substeps

The Particle Fluid solver will always enforce this minimum number of substeps.

This should only rarely need to be changed.

Max Substeps

The Particle Fluid solver will not break the simulation down in to more substeps than this.

It is a very good idea to always have a maximum to ensure frames will be finished regardless of their complexity. Lowering the ceiling can ensure a maximum computation time at the expense of accuracy.

CFL Condition

The CFL condition is a factor used to automatically determine what size substep the scene requires. The idea is to control the distance that a particle in the particle fluid object can travel in a given substep.

When this parameter is set to 0.5, for instance, the solver will set the length of each substep such that no particle travels more than 50% of its particle separation in a given substep.

## Internal Forces

Enable Pressure Force

Enables or disables pressure forces within the particle fluid object being evolved.

Pressure forces act to push particles apart or pull them together to bring them closer to the rest density stored in the particle fluid object.

Pressure Type

The type of pressure force to apply to the system.

Gas Pressure

Applies a fairly simple pressure force which tends to allow for a fairly high degree of compressibility in the evolving fluid.

Liquid Pressure

Applies a somewhat more complicated pressure force which ensures a more liquid-like particle distribution with less compressibility.

Gas Constant

Controls the magnitude of pressure forces applied between pairs of particles.

This parameter effectively controls the compressibility of the fluid. The default value has been chosen because it responds well when settling under standard gravity forces.

If the fluid is required to settle under a gravity force different from the default gravity force, this parameter should be adjusted accordingly. For instance, if the magnitude of the gravity force is scaled up five times, then this parameter should also be scaled up five times.

Enable Viscosity Force

Enables or disables viscosity forces acting between pairs of particles.

Viscosity has the effect of smoothing the particle velocity field, and a highly viscous fluid will appear thicker and less willing to flow than a fluid with low viscosity.

Enable Surface Tension Force

Enables or disables surface tension forces acting between pairs of particles.

Surface tension has the effect of pulling in particles close to the fluid surface. This tends to round out the particle field.

Enable Elastic Force

Enables or disables elastic forces acting between pairs of particles.

Elastic forces act as spring-like bonds between pairs of particles that push particles apart when they get too close together, and pull them together when they get too far apart.

Elasticity Constant

Controls the magnitude of elastic forces acting between pairs of particles.

Plasticity Constant

As the fluid evolves the rest lengths of bonds between pairs of particles is allowed to change as the fluid is stretched or compressed.

This parameter controls the magnitude of changes to these elastic rest lengths. A larger plasticity constant results in a larger deformation of pairwise elastic bonds when the particle set is stretched or compressed.

Plastic Yield Ratio

Controls the amount of deformation that can be resisted by an elastic bond between a pair of particles.

For instance, if this parameter is set to 0.3, then an elastic bond can be stretched or compressed by 30% of its rest length before it begins to deform.

Clamp Number of Springs

Limits the number of particle to particle springs that are created. Since all particles need to have the same size attribute, without clamping many particles close together might result in significant memory usage.

Max Springs

The maximum number of springs that can attach to any one particle. If a particle has more close neighbors than this, they are connected in a closest-first basis.

Use Particle IDs

Determines if the particle springs should store particle id numbers or point numbers. Point numbers are faster to work with, but if points are deleted the springs become invalid.

This tab controls details related to the numerical simulation algorithms used to solve the fluid.

Simulation Method

The numerical simulation method used to control the fluid simulation. See the helpcard for the Gas Integrator DOP for more information on these methods.

Error Tolerance

Tolerance for error in certain simulation methods. See the helpcard for the Gas Integrator DOP for more information on these methods.

Substep Repetition Tolerance

Tolerance for substep repetition, which is performed by certain simulation methods. See the helpcard for the Gas Integrator DOP for more information on these methods.

The technique used to update particle positions. Standard

Particle positions are updated directly using the current particle velocity and time step length.

XSPH

Particle positions are updated using a velocity which is blended between each particle’s current velocity and the average velocity of its neighbors.

XSPH Constant

When Advection Method is set to "XSPH", this constant controls the degree of blending between a particle’s velocity and the velocity of its neighbors. A value of zero ignores neighbor velocities entirely, while larger values increasingly make use of neighbor velocities.

Build Neighbour List

To accelerate repeated searches for close particles, a per-particle list of close particles can be built. This consumes a fair bit of memory, however.

Integrate Orientation

When this toggle is disabled, the integrator only affects the position and velocity attributes of particles in response to values set in the force attribute by the node’s input solvers.

When this toggle is enabled, the integrator also affects the orientation and angular velocity attributes of particles in response to values set in the torque attribute by the node’s input solvers.

Enable Collision Detection

Enables collision detection/response between particles in the system and rigid body objects.

## Distribution

When distributing a particle fluid simulation it is important that each machine uses the same number of substeps. These distribution parameters will synchronize the substeps.

What machine will run the simtracker.py process for synchronization. If this is blank, there will be no attempt at synchronization or data transfer.

Tracker Port

The port specified when starting the simtracker.py process for communication.

Job Name

The job name to describe this synchronization or data exchange event. By using different job names one can have machines part of separate data-exchange and synchronization events.

Slice/Peer

The slice number that this machine should report itself as. Each machine connecting under the job name should have its own unique slice number. Sometimes this can be inferred from the operation so this parameter will be absent.

Number of Slice/Number of Peers

Total number of machines that have to synchronize. Sometimes this can be determined from the operation, so this parameter will be absent.

Parameter Operations

Each data option parameter has an associated menu which specifies how that parameter operates.

Use Default

Use the value from the Default Operation menu.

Set Initial

Set the value of this parameter only when this data is created. On all subsequent timesteps, the value of this parameter is not altered. This is useful for setting up initial conditions like position and velocity.

Set Always

Always set the value of this parameter. This is useful when specific keyframed values are required over time. This could be used to keyframe the position of an object over time, or to cause the geometry from a SOP to be refetched at each timestep if the geometry is deforming.

You can also use this setting in conjunction with the local variables for a parameter value to modify a value over time. For example, in the X Position, an expression like `\$tx + 0.1` would cause the object to move 0.1 units to the right on each timestep.

Set Never

Do not ever set the value of this parameter. This option is most useful when using this node to modify an existing piece of data connected through the first input.

For example, an RBD State DOP may want to animate just the mass of an object, and nothing else. The Set Never option could be used on all parameters except for Mass, which would use Set Always.

Default Operation

For any parameters with their Operation menu set to Use Default, this parameter controls what operation is used.

This parameter has the same menu options and meanings as the Parameter Operations menus, but without the Use Default choice.

Make Objects Mutual Affectors

All objects connected to the first input of this node become mutual affectors.

This is equivalent to using an Affector DOP to create an affector relationship between `*` and `*` before connecting it to this node. This option makes it convenient to have all objects feeding into a solver node affect each other.

Group

When an object connector is attached to the first input of this node, this parameter can be used to choose a subset of those objects to be affected by this node.

Data Name

Indicates the name that should be used to attach the data to an object or other piece of data. If the Data Name contains a "/" (or several), that indicates traversing inside subdata.

For example, if the Fan Force DOP has the default Data Name "Forces/Fan". This attaches the data with the name "Fan" to an existing piece of data named "Forces". If no data named "Forces" exists, a simple piece of container data is created to hold the "Fan" subdata.

Different pieces of data have different requirements on what names should be used for them. Except in very rare situations, the default value should be used. Some exceptions are described with particular pieces of data or with solvers that make use of some particular type of data.

Unique Data Name

Turning on this parameter modifies the Data Name parameter value to ensure that the data created by this node is attached with a unique name so it will not overwrite any existing data.

With this parameter turned off, attaching two pieces of data with the same name will cause the second one to replace the first. There are situations where each type of behavior is desirable.

If an object needs to have several Fan Forces blowing on it, it is much easier to use the Unique Data Name feature to ensure that each fan does not overwrite a previous fan rather than trying to change the Data Name of each fan individually to avoid conflicts.

On the other hand, if an object is known to have RBD State data already attached to it, leaving this option turned off will allow some new RBD State data to overwrite the existing data.

Solver Per Object

The default behavior for solvers is to attach the exact same solver to all of the objects specified in the group. This allows the objects to be processed in a single pass by the solver, since the parameters are identical for each object. However, some objects operate more logically on a single object at a time. In these cases, one may want to use `\$OBJID` expressions to vary the solver parameters across the objects. Setting this toggle will create a separate solver per object, allowing `\$OBJID` to vary as expected.

## Inputs

Fluid to Solve

The simulation object to evolve as a particle fluid.

Prequel Solvers

Sequel Solvers

Additional solvers to apply at the end of each substep in the simulation that do not directly affect the particle fluid object itself.

Solvers such as the Particle Fluid Emitter or Particle Fluid Sink should be connected here.

Additional solvers that apply forces to the particle fluid object; that is, solvers that modify the force point attribute of particles in the object. An example of such a solver is the Gas Vorticle Forces node.

## Outputs

First Output

The operation of this output depends on what inputs are connected to this node. If an object stream is input to this node, the output is also an object stream containing the same objects as the input (but with the data from this node attached).

If no object stream is connected to this node, the output is a data output. This data output can be connected to an Apply Data DOP, or connected directly to a data input of another data node, to attach the data from this node to an object or another piece of data.

## Examples

This example demonstrates how to couple the Particle Fluid with an RBD object so they both affect each other. The result is a buoyant sphere.

FluidGlass Example for Particle Fluid Solver dynamics node

This example demonstrates how to get a smooth fluid stream to pour into a glass.

PopFlow Example for Particle Fluid Solver dynamics node

This example demonstrates how to integrate a POP network with a particle fluid simulation, granting one the Total Artistic Control of POPs with the fluid dynamics of the particle fluid simulator.

PressureExample Example for Particle Fluid Solver dynamics node

This is a simple example demonstrating pressure-driven flow with no viscosity. This example also demonstrates the use of a constantly emitting source of particle fluid as well as how to surface the fluid using the Particle Fluid Surface SOP.

ViscoelasticExample Example for Particle Fluid Solver dynamics node

This example demonstrates the use of viscous and elastic forces in a particle-based fluid to generate viscoelastic fluid behaviour. The result is a fluid-like object that tends to resist deformation and retain its shape.

ViscousFlow Example for Particle Fluid Solver dynamics node

This example demonstrates highly viscous fluid flow using particle-based fluids. Fluids of this form could be used to simulate slowly-flowing fluids such as lava or mud.

WorkflowExample Example for Particle Fluid Solver dynamics node

This somewhat complicated example is meant to demonstrate a simple workflow for simulating, storing, surfacing and rendering a particle fluid simulation. Three geometry nodes in the example are named Step 1, Step 2 and Step 3 according to the order in which they are to be used. They write out particle geometry to disk, read the geometry in and surface it, and read the surfaced geometry from disk, respectively. The example also has shaders and a camera built in so that it can be easily rendered.

The fluid animated in this scene models a highly-elastic gelatin-like blob of fluid.

The following examples include this node.

VolumeSource Example for Particle Fluid Emitter dynamics node

This example demonstrates the use of a volume emitter to fill a container with fluid. The volume of the inside of a tank is specified as volume emission geometry, and particles are emitted randomly at points inside of this geometry for a specified number of frames. This example uses an SPH fluid.

This example demonstrates how to couple the Particle Fluid with an RBD object so they both affect each other. The result is a buoyant sphere.

FluidGlass Example for Particle Fluid Solver dynamics node

This example demonstrates how to get a smooth fluid stream to pour into a glass.

PopFlow Example for Particle Fluid Solver dynamics node

This example demonstrates how to integrate a POP network with a particle fluid simulation, granting one the Total Artistic Control of POPs with the fluid dynamics of the particle fluid simulator.

PressureExample Example for Particle Fluid Solver dynamics node

This is a simple example demonstrating pressure-driven flow with no viscosity. This example also demonstrates the use of a constantly emitting source of particle fluid as well as how to surface the fluid using the Particle Fluid Surface SOP.

ViscoelasticExample Example for Particle Fluid Solver dynamics node

This example demonstrates the use of viscous and elastic forces in a particle-based fluid to generate viscoelastic fluid behaviour. The result is a fluid-like object that tends to resist deformation and retain its shape.

ViscousFlow Example for Particle Fluid Solver dynamics node

This example demonstrates highly viscous fluid flow using particle-based fluids. Fluids of this form could be used to simulate slowly-flowing fluids such as lava or mud.

WorkflowExample Example for Particle Fluid Solver dynamics node

This somewhat complicated example is meant to demonstrate a simple workflow for simulating, storing, surfacing and rendering a particle fluid simulation. Three geometry nodes in the example are named Step 1, Step 2 and Step 3 according to the order in which they are to be used. They write out particle geometry to disk, read the geometry in and surface it, and read the surfaced geometry from disk, respectively. The example also has shaders and a camera built in so that it can be easily rendered.

The fluid animated in this scene models a highly-elastic gelatin-like blob of fluid.

# Dynamics nodes

• Marks a simulation object as active or passive.

• Creates affector relationships between groups of objects.

• Blends between a set of animation clips based on the agent’s turn rate.

• Layers additional animation clips onto an agent.

• Chooses an object/position for the head of an agent to look at.

• Moves the head of an agent to look at a target.

• Adapts the legs of an agent to conform to terrain and prevent the feet from sliding.

• Adapts the legs of a biped agent to conform to terrain.

• Project the agent/particle points onto the terrain

• Defines an orientation that aligns an axis in object space with a second axis defined by the relative locations of two positional anchors.

• Defines multiple points, specified by their number or group, on the given geometry of a simulation object.

• Defines orientations based on multiple points on the given geometry of a simulation object.

• Defines a position by looking at the position of a point on the geometry of a simulation object.

• Defines an orientation by looking at a point on the geometry of a simulation object.

• Defines a position by looking at the position of a point on the geometry of a simulation object.

• Defines an orientation by looking at a point on the geometry of a simulation object.

• Defines a position by looking at the position of a particular UV coordinate location on a primitive.

• Defines a position by specifying a position in the space of some simulation object.

• Defines an orientation by specifying a rotation in the space of some simulation object.

• Defines multiple attachment points on a polygonal surface of an object.

• Defines a position by specifying a position in world space.

• Defines an orientation by specifying a rotation in world space.

• Attaches data to simulation objects or other data.

• Creates relationships between simulation objects.

• Attaches the appropriate data for Bullet Objects to an object.

• Sets and configures an Bullet Dynamics solver.

• Applies a uniform force to objects submerged in a fluid.

• Constrains a set of points on a cloth object to the surface of a Static Object.

• Attaches the appropriate data for Cloth Objects to an object.

• Defines the mass properties.

• Defines the physical material for a deformable surface.

• Defines the internal cloth forces.

• Creates a Cloth Object from SOP Geometry.

• Creates a Cloth Object from SOP Geometry.

• Defines the plasticity properties.

• Constrains part of the boundary of a cloth object to the boundary of another cloth object.

• Defines how cloth uses target.

• Defines a way of resolving collisions involving a cloth object and DOPs objects with volumetric representations (RBD Objects, ground planes, etc.)

• Constrains an object to remain a certain distance from the constraint, and limits the object’s rotation.

• Constrains pairs of RBD objects together according to a polygon network.

• Defines a set of constraints based on geometry.

• Visualizes the constraints defined by constraint network geometry.

• Creates multiple copies of the input data.

• Sets and configures a Copy Data Solver.

• Mimics the information set by the Copy Object DOP.

• Defines a Crowd Fuzzy Logic

• Creates a crowd object with required agent attributes to be used in the crowd simulation.

• Updates agents according to their steer forces and animation clips.

• Update crowd agents based on the custom steerforces and adjusting animation playback of clips

• Defines a Crowd State

• Defines a Crowd State.

• Defines a transition between crowd states.

• Defines a transition between crowd states.

• Defines a Crowd Trigger

• Defines a Crowd Trigger

• Combines multiple crowd triggers to build a more complex trigger.

• Adds a data only once to an object, regardless of number of wires.

• Deletes both objects and data according to patterns.

• Applies force and torque to objects that resists their current direction of motion.

• Defines how the surrounding medium affects a soft body object.

• Controls Embedded Geometry that can be deformed along with the simulated geometry in a finite element simulation.

• Creates an Empty Data for holding custom information.

• Creates an Empty Object.

• Constrains points of a solid object or a hybrid object to points of another DOP object.

• Creates an FEM Hybrid Object from SOP Geometry.

• Constrains regions of a solid object or a hybrid object to another solid or hybrid object.

• Creates a simulated FEM solid from geometry.

• Sets and configures a Finite Element solver.

• Constrains an FEM object to a target trajectory using a hard constraint or soft constraint.

• Attaches the appropriate data for Particle Fluid Objects to become a FLIP based fluid.

• Evolves an object as a FLIP fluid object.

• Applies forces on the objects as if a cone-shaped fan were acting on them.

• Fetches a piece of data from a simulation object.

• Applies forces to an object using some piece of geometry as a vector field.

• Creates a vortex filament object from SOP Geometry.

• Evolves vortex filament geometry over time.

• Imports vortex filaments from a SOP network.

• Saves and loads simulation objects to external files.

• Allows a finite-element object to generate optional output attributes.

• Attaches the appropriate data for Fluid Objects to an object.

• Applies forces to resist the current motion of soft body objects relative to a fluid.

• Attaches the appropriate data for Fluid Objects to an object.

• A solver for Sign Distance Field (SDF) liquid simulations.

• A microsolver that adjusts an internal coordinate system attached to fluid particles in a particle fluid simulation.

• A microsolver that adjusts the strength of elastic bonds between pairs of particles in a fluid simulation.

• A microsolver that advects fields and geometry by a velocity field.

• A microsolver that advects fields and geometry by a velocity field using OpenCL acceleration.

• A microsolver that advects fields and geometry by a velocity field.

• A microsolver that computes analytic property of fields.

• A microsolver that swaps geometry attributes.

• A microsolver that blends the density of two fields.

• A microsolver that blurs fields.

• A microsolver that determines the collision field between the fluid field and any affector objects.

• A microsolver that builds a mask for each voxel to show the presence or absence of relationships between objects.

• A microsolver that calculates an adhoc buoyancy force and updates a velocity field.

• Sets the object to use the Gas Burn solver.

• Creates an object with appropriate data to use as a fire source.

• A microsolver that performs general calculations on a pair of fields.

• A microsolver that detects collisions between particles and geometry.

• A microsolver that applies a combustion model to the simulation.

• A microsolver that calculates particle fluid attribute values for each particle in a particle fluid field.

• A microsolver that adjusts an SDF according to surface markers.

• A microsolver that computes the cross product of two vector fields.

• A DOP node that creates forces generated from a curve.

• A microsolver that applies one round detontation shock dyanamics.

• Attaches the appropriate data for Smoke Objects to become a flame front based fire.

• A microsolver that applies the flamefront-based fire simulation.

• A microsolver that scales down velocity, damping motion.

• A microsolver that diffuses a field or point attribute.

• A microsolver that dissipates a field.

• Adds detail at a certain scale by applying "disturbance" forces to a scalar or vector field.

• Adds detail at a certain scale by applying "disturbance" forces to a scalar or vector field.

• A microsolver that runs once for each matching data.

• A microsolver that computes pairwise elastic forces between particles in a fluid simulation.

• A microsolver that embeds one fluid inside another.

• A microsolver that enforces boundary conditions on a field.

• A microsolver that equalizes the density of two fields.

• A microsolver that equalizes the volume of two fields.

• A microsolver that evaluates the external DOPs forces for each point in a velocity field and updates the velocity field accordingly.

• A microsolver that extrapolates a field’s value along an SDF.

• A microsolver that creates a feathered mask out of a field.

• A microsolver that calculates and applies feedback forces to collision geometry.

• A data node that fetches the fields needed to embed one fluid in another.

• Runs CVEX on a set of fields.

• Runs CVEX on a set of fields.

• A microsolver that copies the values of a field into a point attribute on geometry.

• A microsolver that defragments geometry.

• A microsolver that creates a signed distance field out of geometry.

• Blends a set of SOP volumes into a set of new collision fields for the creation of a guided simulation.

• A microsolver that copies Impact data onto point attributes.

• A microsolver that applies forces to a particle fluid system.

• A microsolver that solves its subsolvers at a regular interval.

• A microsolver that clamps a field within certain values.

• A microsolver that keeps particles within a box.

• A microsolver that combines multiple fields or attributes together.

• A microsolver that adaptively sharpens a field.

• A microsolver that looksup field values according to a position field.

• A microsolver that rebuilds fields to match in size and resolution to a reference field.

• A microsolver that arbitrary simulation data between multiple machines.

• A microsolver that exchanges boundary data between multiple machines.

• A microsolver that exchanges boundary data between multiple machines.

• A microsolver that balances slices data between multiple machines.

• A microsolver that exchanges boundary data between multiple machines.

• Executes the provided kernel with the given paramters

• A microsolver that counts the number of particles in each voxel of a field.

• A microsolver that computes pairwise collision forces between particles that represent instanced spheres.

• A microsolver that moves particles to lie along a certain isosurface of an SDF.

• Updates a neighbourhood list for Geometry to match moved points.

• A microsolver that computes pairwise fluid pressure forces between particles in a fluid simulation.

• A microsolver that separates adjacent particles by adjusting their point positions..

• A microsolver that copies a particle system’s point attribute into a field.

• A microsolver that converts a particle system into a signed distance field.

• A microsolver that removes the divergent components of a velocity field.

• A microsolver that removes the divergent components of a velocity field using a multi-grid method.

• A microsolver that removes the divergent components of a velocity field.

• A microsolver that reduces a field to a single constant field .

• A microsolver that reduces surrounding voxels to a single value.

• A microsolver that reinitializes a signed distance field while preserving the zero isocontour.

• A microsolver that repeatedly solves its input.

• A microsolver that changes the size of fields.

• A microsolver that resizes a fluid to match simulating fluid bounds

• A microsolver that initializes a rest field.

• A microsolver that converts an SDF field to a Fog field.

• A microsolver that calculates the density at particle positions in a particle field using techniques from Smoothed Particle Hydrodynamics.

• A microsolver that uses techniques from Smoothed Particle Hydrodynamics to compute pressure, viscosity and surface tension forces acting between particles in a fluid simulation.

• A microsolver that computes the forces to treat the fluid simulation as sand rather than fluid.

• A microsolver that seeds marker particles around the boundary of a surface.

• A microsolver that seeds particles uniformly inside a surface.

• Applies a Shredding Force to the velocity field specified.

• A microsolver that computes slice numbers into an index field.

• Adjusts a fluid velocity field to match collision velocities.

• A microsolver that calculates the forces imparted by a strain field.

• A microsolver that updates the strain field according to the current velocity field.

• A microsolver that substeps input microsolvers.

• A microsolver that snaps a surface onto a collision surface.

• A microsolver that calculates a surface tension force proportional to the curvature of the surface field.

• A microsolver that applies a force towards a target object.

• Modifies the temperature of a FLIP over time.

• Applies Turbulence to the specified velocity field.

• Up-scales and/or modifies a smoke, fire, or liquid simulations.

• A microsolver that reorients geometry according to motion of a velocity field.

• A microsolver that applies viscosity to a velocity field.

• A microsolver that seeds flip particles into a new volume region.

• Remaps a field according to a ramp.

• Applies a confinement force on specific bands of sampled energy.

• Applies a vortex confinement force to a velocity field.

• Applies a confinement force on specific bands of sampled energy.

• A microsolver that applies forces to a velocity field or geometry according to vorticle geometry.

• A DOP node that adds the appropriately formatted data to represent vorticles.

• A DOP node that recycles vorticles by moving them to the opposite side of the fluid box when they leave.

• A microsolver that performs a wavelet decomposition of a field.

• A microsolver that applies a wind force.

• Runs CVEX on geometry attributes.

• Runs a VEX snippet to modify attribute values.

• Applies a gravity-like force to objects.

• Creates a ground plane suitable for RBD or cloth simulations.

• Creates simulation object groups.

• Defines a constraint relationship that must always be satisfied.

• Attaches the appropriate data for Hybrid Objects to an object.

• Stores filtered information about impacts on an RBD object.

• Applies an impulse to an object.

• Creates an index field.

• Visualizes an index field.

• Creates DOP Objects according to instance attributes

• Marks a simulation object as intangible or tangible.

• Stores the name of the scene level object source for this DOP object.

• Apply forces on objects using a force field defined by metaballs.

• Creates a matrix field.

• Visualizes a matrix field.

• Merges multiple streams of objects or data into a single stream.

• Modifies or creates options on arbitrary data.

• Defines an object’s position, orientation, linear velocity, and angular velocity.

• Unified visualization of multiple fields.

• A DOP that transfers arbitrary simulation data between multiple machines.

• Does nothing.

• Creates position information from an object’s transform.

• Serves as the end-point of the simulation network. Has controls for writing out sim files.

• Uses vortex filaments to move particles.

• A POP node that uses velocity volumes to move particles.

• A POP node that attracts particles to positions and geometry.

• A POP node that copies volume values into a particle attribute.

• A POP node that resets the stopped attribute on particles, waking them up.

• A POP node that applies a force around an axis.

• A POP node that reacts to collisions.

• A POP node that detects and reacts to collisions.

• A POP node marks particles to ignore implicit collisions.

• A POP node that colors particles.

• A POP node that creates forces generated from a curve.

• A POP node that applies drag to particles.

• A POP node that applies drag to the spin of particles.

• A POP node that applies a conical fan wind to particles.

• A POP node that creates a simple fireworks system.

• A POP node that floats particles on the surface of a liquid simulation.

• A POP node that applies a flocking algorithm to particles.

• Controls local density by applying forces between nearby particles.

• A POP node that applies forces to particles.

• A POP node that applies sand grain interaction to particles.

• A POP node that groups particles.

• A POP node that sets up the instancepath for particles.

• A POP node that applies forces between particles.

• A POP node that kills particles.

• A POP node that limits particles.

• A POP node that applies forces within the particle’s frame.

• A POP solver that generates particles at a point.

• A POP node makes a particle look at a point.

• A POP node that applies forces according to metaballs.

• Converts a regular particle system into a dynamic object capable of interacting correctly with other objects in the DOP environment.

• A POP node that sets various common attributes on particles.

• A POP node that sets attributes based on nearby particles.

• A POP Node that generates particles from incoming particles.

• A POP node that creates a spongy boundary.

• A POP solver updates particles according to their velocities and forces.

• A POP node that generates particles from geometry.

• A POP node that sets the speed limits for particles.

• A POP node that sets the spin of particles..

• A POP node that uses the vorticity of velocity volumes to spin particles.

• A POP node that sets the sprite display for particles.

• Applies force to agents/particles to align them with neighbors.

• Applies anticipatory avoidance force to agents/particles to avoid potential future collisions with other agents/particles.

• Applies forces to agents/particles to bring them closer to their neighbors.

• Applies forces to agents/particles calulated using a VOP network.

• Applies force to agents/particles to avoid potential collisions with static objects.

• Applies force to agents/particles to avoid potential collisions with static objects.

• Applies force to agents/particles according to directions from a path curve.

• Applies force to agents/particles to move them toward a target position.

• Apply force to agents/particles to move them apart from each other.

• Used internally in the crowd solver to integrate steering forces.

• Used internally in the crowd solver to integrate custom steering forces.

• Constrains agent velocity to only go in a direction within a certain angle range of its current heading, to prevent agents from floating backward.

• Apply forces to agents/particles to create a random motion.

• A POP node that creates a new stream of particles.

• A POP node that applies torque to particles, causing them to spin.

• Runs CVEX on a particle system.

• A POP node that directly changes the velocity of particles.

• A POP node that applies wind to particles.

• Runs a VEX snippet to modify particles.

• Attaches the appropriate data for Particle Fluid Objects to an object.

• Emits particles into a particle fluid simulation.

• Creates a Particle Fluid Object from SOP Geometry.

• Evolves an object as a particle fluid object.

• Visualizes particles.

• Creates simulation object groups based on an expression.

• Defines the base physical parameters of DOP objects.

• Applies a force to an object from a particular location in space.

• Creates position information from a point on some SOP geometry.

• Associates a position and orientation to an object.

• Sets and configures a Pyro solver. This solver can be used to create both fire and smoke.

• Constrains an RBD object to a certain orientation.

• Constrains an RBD object to have a certain orientation, but with a set amount of springiness.

• Automatically freezes RBD Objects that have come to rest

• Attaches the appropriate data for RBD Objects to an object.

• Creates a number of RBD Objects from SOP Geometry. These individual RBD Objects are created from the geometry name attributes.

• Constrains an object to two constraints, creating a rotation similar to a hinge or a trapeze bar.

• Creates an RBD Object from SOP Geometry.

• Creates a single DOP object from SOP Geometry that represents a number of RBD Objects.

• Constrains an RBD object a certain distance from the constraint.

• Creates a simulation object at each point of some source geometry, similarly to how the Copy surface node copies geometry onto points.

• Sets and configures a Rigid Body Dynamics solver.

• Constrains an object to remain a certain distance from the constraint, with a set amount of springiness.

• Alters the state information for an RBD Object.

• Saves the state of a DOP network simulation into files.

• Applies forces to an object according to the difference between two reference frames.

• Sets and configures a Rigid Body Dynamics solver.

• Attaches the appropriate data for Ripple Objects to an object.

• Creates an object from existing geometry that will be deformed with the ripple solver.

• Animates wave propagation across Ripple Objects.

• Creates a signed distance field representation of a piece of geometry that can be used for collision detection.

• A microsolver that performs general calculations on a pair consisting of a DOP field and a SOP volume/VDB.

• Creates a scalar field from a SOP Volume.

• Creates a vector field from a SOP Volume Primitive.

• Creates a scalar field.

• Visualizes a scalar field.

• Defines the internal seam angle.

• Defines the mass density of a Cloth Object.

• Divides a particle system uniformly into multiple slices along a line.

• Specifies a cutting plane to divide a particle system into two slices for distributed simulations.

• Constrains an object to rotate and translate on a single axis, and limits the rotation and translation on that axis.

• Attaches the appropriate data for Smoke Objects to an object.

• Creates an Smoke Object from SOP Geometry.

• Sets and configures a Smoke solver. This is a slightly lower-level solver that is the basis for the Pyro solver.

• Constrains a set of points on a soft body object to a certain position using a hard constraint or soft constraint.

• Constrains a point on a soft body object to a certain position.

• Constrains a point on a soft body to a certain position, with a set amount of springiness.

• Defines how a soft body object responds to collisions.

• Defines how a Soft Body Object responds to collisions.

• Defines how a Soft Body Object responds to collisions.

• Defines how a Soft Body Object responds to collisions.

• Allows the user to import the rest state from a SOP node.

• Sets and configures a Soft Body solver.

• Defines the strengths of the soft constraint on a soft body object.

• Controls the anisotropic behavior of a Solid Object.

• Attaches the appropriate data for Solid Objects to an object.

• Defines the mass density of a Solid Object.

• Defines how a Solid Object reacts to strain and change of volume.

• Creates a Solid Object from SOP Geometry.

• This builds a tree of spheres producing bounding information for an edge cloud.

• This builds a tree of spheres producing bounding information for a point cloud.

• Splits an incoming object stream into as many as four output streams.

• Creates a Static Object from SOP Geometry.

• Allows you to inspect the behavior of a static object in the viewport.

• Control the thickness of the object that collides with cloth.

• Passes one of the input object or data streams to the output.

• Creates a Terrain Object from SOP Geometry.

• Defines a way of resolving collisions between two rigid bodies.

• Applies a uniform force and torque to objects.

• Applies forces on the objects according to a VOP network.

• Creates a vector field.

• Visualizes a vector field.

• Modifies common Vellum Constraint properties during a Vellum solve.

• Microsolver to create Vellum constraints during a simulation.

• Creates a DOP Object for use with the Vellum Solver.

• Blends the current rest values of constraints with a rest state calculated from the current simulation or external geometry.

• Sets and configures a Vellum solver.

• A Vellum node that creates Vellum patches.

• Applies an impulse to an object.

• A microsolver to create soft references to visualizers on itself.

• Imports SOP source geometry into smoke, pyro, and FLIP simulations.

• Defines a way of resolving collisions involving two rigid bodies with volume.

• Attaches the appropriate data to make an object fractureable by the Voronoi Fracture Solver

• Defines the parameters for dynamic fracturing using the Voronoi Fracture Solver

• Dynamically fractures objects based on data from the Voronoi Fracture Configure Object DOP

• Applies a vortex-like force on objects, causing them to orbit about an axis along a circular path.

• Creates a Whitewater Object that holds data for a whitewater simulation.

• Creates a Whitewater Object that holds data for a whitewater simulation.

• Sets and configures a Whitewater Solver.

• Sets and configures a Whitewater solver.

• Applies forces to resist the current motion of objects relative to a turbulent wind.

• Constrains a wire point’s orientation to a certain direction.

• Constrains a wire point’s orientation to a certain direction, with a set amount of springiness.

• Attaches the appropriate data for Wire Objects to an object.

• Defines the elasticity of a wire object.

• Constraints a wire point to a certain position and direction.

• Creates a Wire Object from SOP Geometry.

• Defines the physical parameters of a wire object.

• Defines the plasticity of a wire object.

• Sets and configures a Wire solver.

• Defines a way of resolving collisions involving a wire object and DOPs objects with volumetric representations.

• Defines a way of resolving collisions between two wires.