Houdini 18.5 Nodes Geometry nodes

Vellum Solver geometry node

Runs a dynamic Vellum simulation.

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Since 17.0

The Vellum Solver is a wrapper around a DOP network to simplify the running of Vellum solves.

Like most Vellum SOPs, it is a three input SOP. The first input is the surface geometry to solve. The second input should have the same number of points as the first, with point-to-point correspondence either with point numbers or id attributes. The second input also should have special primitives describing the constraint relationships. Constraints are how the connectivity between points are defined and controlled and can be created with a Vellum Constraints SOP. Note that the network tab menu has several macros to refer to common setups, such as Vellum Configure Cloth. The third input provides the collision geometry. The collision geometry should have matching topology frame-to-frame. In addition, some types of packed geometry are recognized.

You can dive into the solver to add DOP nodes to apply special forces. You can also use the Vellum Constraint Property DOP to adjust the constraint properties during the solve using these internal nodes.

If using collisionignore, the third input’s object can be referred to as external and the generated ground plane as groundplane.

Parameters

Reset Simulation

Clears the entire simulation cache.

Start Frame

What frame on the Houdini playbar that the simulation should begin at.

Solver

Time Scale

Scales the effective time of the Vellum solve. This can be used to create bullet-time like effects where the physics of the Vellum solver run at a different rate than the Houdini playbar. A value of 2 will cause cloth to fall twice as fast, and 0.1 will slow it to a tenth the speed.

Substeps

Each frame will be broken into this number of substeps. Additional substeps are required for fast moving collisions or sudden forces.

The default substeps can be very aggressive, usually if the Vellum solver is too stretchy, raising substeps to 2 or 5 is a good first start.

Constraint Iterations

Within each substep, this number of passes will be taken by the constraint enforcement operations. Stiff constraints can require more iterations to converge. A good starting point is the diameter of the geometry - the number of edges between the farthest points.

Smoothing Iterations

The default constraint iterations use a Gauss-Seidel approach that is fast to converge. However, if it doesn’t fully converge due to too high stiffness, or impossible configurations, it will leave the error as bad looking triangles. The smoothing iterations use a Jacobi approach which is slower to converge but leaves error spread out in a more attractive fashion. The default of ten passes helps smooth out error, but might need to be increased if the overall Constraint Iterations is very high.

Collisions

Enable Collisions

Controls if any collision detection is done at all.

Self Collisions

Controls if self collisions are detected.

Ground Plane

Adds a ground plane to the simulation. The ground plane will be visualized with a blue grid.

Ground Position

Location of the center of the ground plane.

Collision Passes

Number of collision detection passes to perform. These are interleaved between the constraint iterations. Since collision is expensive, it is best to minimize this. But frequent interleaving helps avoid tent-poling effects where a small collider is fighting with the no-stretch constraints. In practice we find 10 to be correct for most situations, and substeps often being a better solution to increase quality.

Post Collision Passes

After all constraints are performed, a final round of collision detection is done. Collisions are often the most noticeable failure mode, and it is ideal if the next frame can start with non-intersecting geometry. Thus a final cleanup pass can achieve these requirements. We have found that "number of stacked layers + 2" is a good estimate for this number. This allows the effect of the underlying collider to ripple through the stacked layers fully.

Polish Passes

In any collision pass, any colliding pair may not be fully resolved. This number of additional collider-pair passes will be run until they are resolved. Since these are only performed on active colliders (and no new collision search is done) this is very cheap.

Layer Shock

The layer integer point attribute is used to flag point as belonging to different layers of cloth. Higher numbers refer to higher layers. Layer Shock will make lower layers this many times heavier during collision evaluation, ensuring the higher layers will move out of their way. The rest of the dynamics are unaffected by this, and the difference is fixed regardless of the number of layers between the two. This can be thought of as a way to dial between one-way layering of sims and fully coupled sims.

Forces

Gravity

Uniform gravity force to apply.

Wind

A uniform wind direction. Since this is a drag force, a wind of zero will act like still air and slow everything down; and a high wind will speed cloth up to that speed.

Wind Drag

The amount the particles are dragged by the wind force. This is also scaled by the tangential and normal drag forces specified on the Vellum Constraints SOP to provide unequal drag depending on orientation.

Velocity Damping

A more brute force approach to reducing dynamic velocity - the velocity is scaled directly by this amount, causing sudden movements to be quickly damped.

Friction

Static Threshold

A threshold at which to apply full friction. When the ratio of the tangential velocity and the normal impulse is less than this, the tangential velocity will be fully eliminated through friction. This is roughly tan() of the slope angle that will allow sliding under gravity.

Dynamic Scale

If the static threshold fails, this controls what percentage the tangential velocity will be reduced in the dynamic friction case.

Enable External

A scale factor on the amount of friction effect to apply for collisions with external geometry.

Enable Self

A scale factor on the amount of friction effect to apply for collisions with self geometry.

Ground Static Scale

A scale factor for the ground plane’s static friction. Useful to create frictionless grounds.

Ground Dynamic Scale

A scale factor for the ground plane’s dynamic friction. Useful to create frictionless grounds.

Simulation

Cache Enabled

Controls if the simulation is cached to memory.

Cache Memory (MB)

Maximum size of the memory cache.

Simulation Type

Style of the simulation.

Quasistatic

Each frame the simulation takes the inputs and runs them forward the given number of frames. The final result becomes that frames result. No frame-to-frame coherency is present.

Dynamic

Each frame is solved from the previous frame, and the inputs are used to setup the first frame only.

Quasistatic Frames

The number of frames to roll forward for the quasi-static simulation.

Clear Dynamics

All dynamic forces and states, such as velocities, are removed from the output. This allows the output of a clean state to start a new simulation from, such as when completing a drape.

Advanced

Target

Points on the simulation mesh can be marked as Pin to Target to follow the targeted animation. By default, this target is the first input. But in some cases the animation you wish to target may be present in another SOP node, so that can be specified here.

Target Path

The path of a node to refer to when simulation points are set to the target animation. Should have a one-to-one point correspondence with the simulation points, either by point number or id.

Integration

When integrating points forward by their velocities, curved motions like swinging pendulums will be mispredicted and be damped by the constraint projections. A second order predictor recovers more of this curved motion and maintains more energy in the system.

In any case, if collisions are detected the system will fall back to first order to avoid excessive bouncing.

Secondary Constraint Pass

Enable Secondary Constraint Pass

If this checkbox is turned on, all constraints in the specified Constraint Group will be solved in a separate, interleaved pass to the remaining constraints.

There are two main uses for this option. First, there are some expensive constraint types that do not need to be solved as frequently as the rest of the constraints, so enabling this option and choosing a low Solve Frequency can improve performance. For example, cloth bend constraints on high resolution cloth with low bend stiffness such a silk or cotton. You need to ensure that you're solving distance constraints every pass so the cloth doesn’t stretch. However, bend constraints are expensive and don’t need to be as strong, since silk and cotton have very low bend resistance and wrinkle easily. Solving the bend constraints as a secondary pass will give you strong performance gains. However, this method isn’t practical for stiffer material such as leather.

The second use case is constraints that cause frequent changes in the constraint topology, which causes the solver to re-order the constraint solve, possibly causing jittering in the remaining constraints. An example is organic tissue represented by tetrahedra and attached together with sliding Stitch constraints. As the sliding causes changes in the constraint topology the tetrahedra might jitter slightly as the constraint solve order changes. Moving the Stitch constraints to another pass by setting Constraint Group to @type=ptprim and increasing the Solve Frequency to 1 will retain the same stiffness but eliminate tetrahedral jittering due to changes in the solve order.

Constraint Group

The constraint group(s) that should be solved in the interleaved secondary pass. This parameter accepts standard group syntax, so can contain explicit group names and ad-hoc groups, often specifying one or more constraint types with something like @type==bend. Any constraint not contained in these groups will be solved in the primary pass as usual.

Solve Frequency

The frequency at which to solve the secondary pass. A setting of 1 will solve the secondary pass as often as the primary pass, while a setting of 0.25 will solve once every four passes of the primary pass (one quarter of the time).

Multi-Pass Solve

Enable Multi-Pass

The multi-pass options allow a substep to be repeated until certain conditions are met. The current conditions are designed to fix issues that are caused by disabled points causing geometry to be caught and cause the undisabled points to generate stretching. Since collisions always pre-empt constraints, the result is cloth or hair stretching. Points adjacent to auto-disabled points will be themselves disabled if too much stretching is detected. The solve step will then be repeated in the hopes this frees up the geometry.

Maximum Passes

The maximum number of times to repeat the substep. If no new points need to be disabled, the process will stop immediately.

Disable Stretch Ratio

The amount of stretch at the end of a solve step that will trigger points to be eligible for disabling. This is to detect when failed collisions are pulling the Vellum object apart. By failing additional points the object usually can be released and result in a better result than continuing to stretch.

Motion

Max Acceleration

Various acceleration limiting options can be used to prevent the simulation from being over-eager to obey non-realistic forces. These can otherwise result in large energy spikes.

Fallback to First Order Integration on Collision

If Max Acceleration is exceeded for a point, assume it signals a sharp, discontinuous collision where the second order prediction will be wrong and add erroneous motion, often in the form of bouncing. In this case, fallback to first order integration for the affected point.

Limit Acceleration in Velocity Update

Cap the amount that velocity of a particle is allowed to change as a result of any of the dynamics. This is useful to prevent some instant motion being mis-identified as a massive force, and thus avoid fly-away particles.

Limit Displacement on Collision

During the collision resolution, if the collision correction moves a particle more than the acceleration amount, cap the effect. The hope is to fail more gracefully when a part of a model snags on the cloth and is pulling it in a surprising fashion.

Disable Broken Welds

When a weld breaks, the two new points start off next to each other. If the surfaces do not separate naturally due to whatever triggered the break, they may trigger collision detection and be pushed out, causing an explosive motion when breaking occurs. This option sets the disableself attribute when points are de-welded to avoid these self collisions. Note that this may cause layered cloth to self penetrate, however.

Normalize Stress

Normalize the stress computation over time, so that the computed values are more predictable as the Substeps parameter changes.

Sliding Method

The method used for finding the next closest position on the target geometry when sliding Attach to Geometry or Stitch Points constraints. Closest Point simply chooses the closest point on the target geometry to the projected sliding position. This approach is fast but can improperly jump across concavities in the target geometry. Traverse Polygons starts from the current target primitive and successively walks outwards, finding the closest point on the surrounding primitives. This approach is more expensive but handles concave target geometry better. Traverse Triangles (Optimized) is similar to the previous option in its improved handling of concavities, but can be many times faster as it uses specialized triangle distance functions. However, it can only be used with target geometry consisting of triangles.

Tip

Target geometry with quadrilaterals can be triangulated with the Divide SOP.

OpenCL

OpenCL Graph Coloring

When doing graph coloring, a fast parallel OpenCL algorithm is used. Unfortunately it may require 10× more memory than the rest of the solve on tetrahedral meshes. Thus, systems that might fit in memory for solving will not succeed the color pass. Disabling this forces all graph coloring to be done in a slower sequential manner, preserving RAM for the actual solve.

Visualize

Show Collision

Show the collision object as a blue wireframe.

Show Guide Geometry

Show additional guide geometry from the solver.

Geometry

Thickness

Draw spheres for the pscale of the geometry. If the geometry has already solved it may have set the overlap_self attribute, if so, the actual effective thickness is drawn in cyan. This is useful to detect if the original thickness was too high - if so the extra thickness will be ignored by the simulation and just slow down the collisions.

Extrude

Draw the thickness by offsetting the geometry in opposite directions rather than by using spheres.

Failed Self Collision

Draw failed self collisions as red spheres. These points will no longer collide with their own geometry, nor will any edge or triangle attached to them.

Failed External Collision

Draw failed external collisions as orange spheres. These points will no longer collide with external geometry, nor will any edge or triangle attached to them.

Welds

Draw which points have been semantically fused together with the weld attribute. These can be broken during the solve using the auto break options, or by setting weld to -1.

Radius Scale

Because the thickness may be small, the visualization spheres can sometimes be lost. This scales the visualization spheres allowing them to be readily seen.

Constraints

Group

Constraints are often added to different groups. This allows you to isolate one particular group to visualize.

Pin to Target

Draw spheres over points pinned to the target animation.

Stitch Points

Draw stitch constraints of points stitched together.

Attach to Geometry

Draw attachment constraints for points attached to external geometry.

Radius

The constraint guides are not scaled by the thickness of the object, so this provides an absolute scale for their size.

Visualization

False Color Mode

Visualize properties of the constraints using a blue-to-red infrared coloring.

None

Leave the original colors.

Stretch Stress

Color according to the maximum stretching force applied by the constraints.

Bend Stress

Color according to the maximum bending force applied by the constraints.

Stretch Distance

Color according to how far constraints are stretched.

Stretch Ratio

Color according the ratio between original and current stretch.

Bend Angle

Color according to how many degrees the bend angle has deviated.

Stretch Plastic Flow

Color according to how much the stretch plastic flow has been triggered.

Bend Plastic Flow

Color according to how much the bend plastic flow has been triggered.

Volume Stress

Color according to the maximum volumetric force applied by the constraints.

Volume Distance

Color according to how far volumetric constraints have expanded from their rest state.

Volume Ratio

Color according the ratio between volumetric expansion and the rest state.

Display Visualization Geometry

Toggles if the simulation geometry is false-colored in addition to the constraints.

Max Stretch Stress

Scales the maximum stretch stress to be the maximum coloration.

Max Bend Stress

Scales the maximum bend stress to be the maximum coloration.

Max Stretch Distance

Sets the maximum stretch distance to be the maximum coloration.

Max Stretch Ratio

Sets the maximum stretch ratio to be the maximum coloration.

Max Bend Angle

Sets the maximum bend angle to be the maximum coloration.

Max Stretch Plastic Flow

Sets the maximum stretch plastic flow to be the maximum coloration.

Max Bend Plastic Flow

Sets the maximum bend plastic flow to be the maximum coloration.

Max Volume Stress

Scales the maximum volume stress to be the maximum coloration.

Max Volume Distance

Scales the maximum volume distance to be the maximum coloration.

Max Volume Ratio

Scales the maximum volume ratio to be the maximum coloration.

Examples

AnimatedConstraints Example for Vellum Solver geometry node

This example demonstrates animating Vellum constraint properties during simulation.

AnimatedPressure Example for Vellum Solver geometry node

This example demonstrates using the pressurescale attribute to create an animated inflation effect with the VellumSolver’s pressure constraint.

ArmLayer Example for Vellum Solver geometry node

This example demonstrates using the layer point attribute to improve collisions when simulating multiple layers of Vellum cloth.

ArmTarget Example for Vellum Solver geometry node

This example demonstrates using Pin to Target constraints to attract Vellum cloth to capture / deformed geometry.

CollisionDisable Example for Vellum Solver geometry node

This examples demonstrates using the disableexternal attribute to disable Vellum collisions on a point-by-point basis.

CollisionIgnore Example for Vellum Solver geometry node

This examples shows to use point attributes to directly control collisions with collisionignore and collisiongroup.

DynamicAttach Example for Vellum Solver geometry node

This example shows how to create Attach to Geometry constraints during a Vellum simulation based on proximity to a collision object.

DynamicStitchGlue Example for Vellum Solver geometry node

This example demonstrates dynamically stitching or gluing Vellum geometry together during a simulation.

GluedGrains Example for Vellum Solver geometry node

This example demonstrates gluing Vellum Grains together for sticky particle effects.

HairOrient Example for Vellum Solver geometry node

This example shows the most efficient and stable way to update the orientation for hair guides going into the Vellum Solver when used outside the standard Grooming tools.

ResolutionTarget Example for Vellum Solver geometry node

This examples shows how to target a hi-res Vellum cloth simulation to a previous low-res simulation to maintain overall motion while still getting fine wrinkles.

SimpleWeld Example for Vellum Solver geometry node

This example demonstrates simple breaking welds for tearing cloth using the Vellum solver.

StiffnessDropoff Example for Vellum Solver geometry node

This example demonstrates creating softly releasing Pin constraints using the Stiffness Dropoff parameter.

TetrahedralFiber Example for Vellum Solver geometry node

This example demonstrates the Tetrahedral Fiber constraint for simulating contracting softbodies.

VaryingFriction Example for Vellum Solver geometry node

This examples shows to use point attributes to get varying friction in Vellum cloth simulations.

See also

Geometry nodes

  • Adapt to Terrain

    Adapts a character’s skeleton to conform to terrain.

  • Adaptive Prune

    Removes elements while trying to maintain the overall appearance.

  • Add

    Creates Points or Polygons, or adds points/polys to an input.

  • Agent

    Creates agent primitives.

  • Agent Animation Unpack

    Extracts animation or MotionClips from an agent primitive.

  • Agent Character Unpack

    Extracts the rest geometry, skeleton, and animation from an agent primitive.

  • Agent Clip

    Adds new clips to agent primitives.

  • Agent Clip Properties

    Defines how agents' animation clips should be played back.

  • Agent Clip Transition Graph

    Creates geometry describing possible transitions between animation clips.

  • Agent Collision Layer

    Creates a new agent layer that is suitable for collision detection.

  • Agent Configure Joints

    Creates point attributes that specify the rotation limits of an agent’s joints.

  • Agent Constraint Network

    Builds a constraint network to hold an agent’s limbs together.

  • Agent Definition Cache

    Writes agent definition files to disk.

  • Agent Edit

    Edits properties of agent primitives.

  • Agent Layer

    Adds a new layer to agent primitives.

  • Agent Look At

    Adjusts the head of an agent to look at a specific object or position.

  • Agent Pose from Rig

    Updates an agent primitive’s pose from a geometry skeleton.

  • Agent Prep

    Adds various common point attributes to agents for use by other crowd nodes.

  • Agent Proxy

    Provides simple proxy geometry for an agent.

  • Agent Relationship

    Creates parent-child relationships between agents.

  • Agent Terrain Adaptation

    Adapts agents' legs to conform to terrain and prevent the feet from sliding.

  • Agent Transform Group

    Adds new transform groups to agent primitives.

  • Agent Unpack

    Extracts geometry from agent primitives.

  • Agent Vellum Unpack

    Extracts geometry from agent primitives for a Vellum simulation.

  • Agent from Rig

    Creates an agent primitive from a geometry skeleton.

  • Alembic

    Loads the geometry from an Alembic scene archive (.abc) file into a geometry network.

  • Alembic Group

    Creates a geometry group for Alembic primitives.

  • Alembic Primitive

    Modifies intrinsic properties of Alembic primitives.

  • Alembic ROP output driver

  • Align

    Aligns a group of primitives to each other or to an auxiliary input.

  • Assemble

    Cleans up a series of break operations and creates the resulting pieces.

  • Attach Control Geometry

    Creates control geometry for SOP-based KineFX rigs.

  • Attribute Adjust Float

    Modifies floating point attribute values on the incoming geometry.

  • Attribute Adjust Integer

    Modifies integer attribute values on the incoming geometry.

  • Attribute Adjust Vector

    Modifies values for a vector-type attribute on the incoming geometry.

  • Attribute Blur

    Blurs out (or "relaxes") points in a mesh or a point cloud.

  • Attribute Cast

    Changes the size/precision Houdini uses to store an attribute.

  • Attribute Composite

    Composites vertex, point, primitive, and/or detail attributes between two or more selections.

  • Attribute Copy

    Copies attributes between groups of vertices, points, or primitives.

  • Attribute Create

    Adds or edits user defined attributes.

  • Attribute Delete

    Deletes point and primitive attributes.

  • Attribute Expression

    Allows simple VEX expressions to modify attributes.

  • Attribute Fade

    Fades a point attribute in and out over time.

  • Attribute From Pieces

    Assigns an attribute to points specifying which of a set of models should be copied/instanced to that point, randomly or based on various rules.

  • Attribute Interpolate

    Interpolates attributes within primitives or based on explicit weights.

  • Attribute Mirror

    Copies and flips attributes from one side of a plane to another.

  • Attribute Noise

    Adds or generates noise in geometry attributes.

  • Attribute Paint

    Interactively paint point attributes, such as color or deformation mask values, directly on geometry.

  • Attribute Promote

    Promotes or demotes attributes from one geometry level to another.

  • Attribute Randomize

    Generates random attribute values of various distributions.

  • Attribute Remap

    Fits an attribute’s values to a new range.

  • Attribute Rename

    Renames or deletes point and primitive attributes.

  • Attribute Reorient

    Modifies point attributes based on differences between two models.

  • Attribute String Edit

    Edits string attribute values.

  • Attribute Swap

    Copies, moves, or swaps the contents of attributes.

  • Attribute Transfer

    Transfers vertex, point, primitive, and/or detail attributes between two models.

  • Attribute Transfer By UV

    Transfers attributes between two geometries based on UV proximity.

  • Attribute VOP

    Runs a VOP network to modify geometry attributes.

  • Attribute Wrangle

    Runs a VEX snippet to modify attribute values.

  • Attribute from Map

    Samples texture map information to a point attribute.

  • Attribute from Parameters

    Creates a dictionary attribute filled with parameter values.

  • Attribute from Volume

    Copies information from a volume onto the point attributes of another piece of geometry, with optional remapping.

  • Bake ODE

    Converts primitives for ODE and Bullet solvers.

  • Bake Volume

    Computes lighting values within volume primitives

  • Ballistic Path

    Generates ballistic projectile paths from the incoming points.

  • Basis

    Provides operations for moving knots within the parametric space of a NURBS curve or surface.

  • Bend

    Applies captures such as bend, twist, taper, and squash/stretch.

  • Blast

    Deletes primitives, points, edges or breakpoints.

  • Blend Shapes

    Computes a 3D metamorphosis between shapes with the same topology.

  • Block Begin

    The start of a looping block.

  • Block Begin Compile

    The start of a compile block.

  • Block End

    The end/output of a looping block.

  • Block End Compile

    The end/output of a compile block.

  • Bone Capture

    Supports Bone Deform by assigning capture weights to bones.

  • Bone Capture Biharmonic

    Supports Bone Deform by assigning capture weights to points based on biharmonic functions on tetrahedral meshes.

  • Bone Capture Lines

    Utility node that supports Bone Capture Biharmonic by creating lines from bones with suitable attributes.

  • Bone Capture Proximity

    Supports Bone Deform by assigning capture weights to points based on distance to bones.

  • Bone Deform

    Uses capture attributes created from bones to deform geometry according to their movement.

  • Bone Link

    Creates default geometry for Bone objects.

  • Boolean

    Combines two polygonal objects with boolean operators, or finds the intersection lines between two polygonal objects.

  • Boolean Fracture

    Fractures the input geometry using cutting surfaces.

  • Bound

    Creates a bounding box, sphere, or rectangle for the input geometry.

  • Box

    Creates a cube or six-sided rectangular box.

  • Bulge

    Deforms the points in the first input using one or more magnets from the second input.

  • COP2 Network

    Imports 2d geometry from a Composite network.

  • Cache

    Records and caches its input geometry for faster playback.

  • Cap

    Closes open areas with flat or rounded coverings.

  • Capture Attribute Pack

    Converts array attributes into a single index-pair capture attribute.

  • Capture Attribute Unpack

    Converts a single index-pair capture attribute into per-point and detail array attributes.

  • Capture Correct

    Adjusts capture regions and capture weights.

  • Capture Layer Paint

    Lets you paint capture attributes directly onto geometry.

  • Capture Mirror

    Copies capture attributes from one half of a symmetric model to the other.

  • Capture Override

    Overrides the capture weights on individual points.

  • Capture Packed Geometry

    Rigidly capture input packed geometry to a SOP skeleton.

  • Capture Region

    Supports Capture and Deform operation by creating a volume within which points are captured to a bone.

  • Carve

    Slices, cuts or extracts points or cross-sections from a primitive.

  • Chain

    Repeats one or more pieces of geometry along a curve.

  • Channel

    Reads sample data from a chop and converts it into point positions and point attributes.

  • Character Blend Shapes

    Applies blend shapes to a KineFX character’s geometry using the weight attributes on its skeleton.

  • Character I/O

    Packs Character mesh, capture pose and animation, saves them to disk, and loads them back again.

  • Character Pack

    Creates a packed geometry primitive from a rest geometry, skeleton, and animation inputs.

  • Character Unpack

    Extracts the rest geometry, skeleton, and animation from an packed geometry primitive.

  • Circle

    Creates open or closed arcs, circles and ellipses.

  • Circle from Edges

    Transforms selected geometry into a circle.

  • Clay

    Lets you deform NURBS faces and NURBS surfaces by pulling points that lie directly on them.

  • Clean

    Helps clean up dirty models.

  • Clip

    Removes or groups geometry on one side of a plane, or creases geometry along a plane.

  • Cloth Capture

    Captures low-res simulated cloth.

  • Cloth Deform

    Deforms geometry captured by the Cloth Capture SOP.

  • Cloud

    Creates a volume representation of source geometry.

  • Cloud Light

    Fills a volume with a diffuse light.

  • Cloud Noise

    Applies a cloud like noise to a Fog volume.

  • Cluster

    Low-level machinery to cluster points based on their positions (or any vector attribute).

  • Cluster Points

    Higher-level node to cluster points based on their positions (or any vector attribute).

  • Collision Source

    Creates geometry and VDB volumes for use with DOPs collisions.

  • Color

    Adds color attributes to geometry.

  • Comb

    Adjust surface point normals by painting.

  • Compute Rig Pose

    Evaluates a multiparm of transform parameters and applies them to the input skeleton.

  • Compute Transform

    Recomputes world space or local space transforms for points in a hierarchy.

  • Configure Clip Info

    Edits properties of a skeleton animation or motion clip.

  • Connect Adjacent Pieces

    Creates lines between nearby pieces.

  • Connectivity

    Creates an attribute with a unique value for each set of connected primitives or points.

  • Control

    Creates simple geometry for use as control shapes.

  • Convert

    Converts geometry from one geometry type to another.

  • Convert HeightField

    Converts a 2D height field to a 3D VDB volume, polygon surface, or polygon soup surface.

  • Convert Line

    Converts the input geometry into line segments.

  • Convert Meta

    Polygonizes metaball geometry.

  • Convert Tets

    Generates the oriented surface of a tetrahedron mesh.

  • Convert VDB

    Converts sparse volumes.

  • Convert VDB Points

    Converts a Point Cloud into a VDB Points Primitive, or vice versa.

  • Convert Volume

    Converts the iso-surface of a volume into a polygonal surface.

  • Convex Decomposition

    Decomposes the input geometry into approximate convex segments.

  • Copy Stamp

    Creates multiple copies of the input geometry, or copies the geometry onto the points of the second input.

  • Copy and Transform

    Copies geometry and applies transformations to the copies.

  • Copy to Curves

    Copies geometry in the first input onto curves of the second input.

  • Copy to Points

    Copies geometry in the first input onto the points of the second input.

  • Crease

    Manually adds or removes a creaseweight attribute to/from polygon edges, for use with the Subdivide SOP.

  • Creep

    Deforms and animates a piece of geometry across a surface.

  • Cross Section Surface

    Creates a surface around cross sections.

  • Crowd Source

    Populates a crowd of agent primitives.

  • Curve

    Creates polygonal, NURBS, or Bezier curves.

  • Curveclay

    Deforms a spline surface by reshaping a curve on the surface.

  • Curvesect

    Finds the intersections (or points of minimum distance) between two or more curves or faces.

  • DOP I/O

    Imports fields from DOP simulations, saves them to disk, and loads them back again.

  • DOP Import Fields

    Imports scalar and vector fields from a DOP simulation.

  • DOP Import Records

    Imports option and record data from DOP simulations into points with point attributes.

  • DOP Network

  • Debris Source

    Generates point emission sources for debris from separating fractured rigid body objects.

  • Deformation Wrangle

    Runs a VEX snippet to deform geometry.

  • Delete

    Deletes input geometry by group, entity number, bounding volume, primitive/point/edge normals, and/or degeneracy.

  • Delete Joints

    Delete Joints on a SOP Rig.

  • DeltaMush

    Smooths out (or "relaxes") point deformations.

  • Denoise AI

    Uses machine-learning algorithms to denoise images with high quality and speed.

  • Detangle

    Attempts to prevent collisions when deforming geometry.

  • Dissolve

    Deletes edges from the input polygonal geometry merging polygons with shared edges.

  • Distance Along Geometry

    Measures the distance of the shortest path along the geometry’s edges or surfaces from each start point.

  • Distance from Geometry

    Measures distance between each point and a reference geometry.

  • Distance from Target

    Measures distance of each point from a target.

  • Divide

    Divides, smooths, and triangulates polygons.

  • Dop Import

    Imports and transforms geometry based on information extracted from a DOP simulation.

  • Draw Curve

    Creates a curve based on user input in the viewport.

  • Draw Guides

  • Dynamic Warp

    Dynamically Time-warps the first input (the Source) using the second input (the Reference) as a reference.

  • Each

    Culls the input geometry according to the specifications of the For Each SOP.

  • Edge Collapse

    Collapses edges and faces to their centerpoints.

  • Edge Cusp

    Sharpens edges by uniquing their points and recomputing point normals.

  • Edge Divide

    Inserts points on the edges of polygons and optionally connects them.

  • Edge Equalize

    Transforms selected edges so that all edges are of equal length.

  • Edge Flip

    Flips the direction of polygon edges.

  • Edge Fracture

    Cuts geometry along edges using guiding curves.

  • Edge Straighten

    Straightens selected edges.

  • Edge Transport

    Copies and optionally modifies attribute values along edges networks and curves.

  • Edit

    Edits points, edges, or faces interactively.

  • Ends

    Closes, opens, or clamps end points.

  • Enumerate

    Sets an attribute on selected points or primitives to sequential numbers or strings.

  • Error

    Generates a message, warning, or error, which can show up on a parent asset.

  • Exploded View

    Pushes geometry out from the center to create an exploded view.

  • Export Object Transforms

    Export transform attributes to object nodes.

  • Extract Centroid

    Computes the centroid of each piece of the geometry.

  • Extract Locomotion

    Extracts translation and orientation from a character using a given input joint.

  • Extract Point from Curve

    Creates new points where an interpolated attribute has a certain value on a curve.

  • Extract Transform

    Computes the best-fit transform between two pieces of geometry.

  • Extrude

    Extrudes geometry along a normal.

  • Extrude Volume

    Extrudes surface geometry into a volume.

  • FBIK Configure Joints

    Configures joint properties used by full-body inverse kinematics solvers.

  • FBIK Configure Targets

    Configures joint properties used by full-body inverse kinematics solvers.

  • FBX Animation Import

    Import animation from an FBX file as a geometry-based skeleton.

  • FBX Character Import

    Import a skinned character from an FBX file with animation.

  • FBX Skin Import

    Import skin geometry from an FBX file.

  • FEM Validate

    Visualizes the quality of a tetrahedral mesh.

  • FEM Visualize

  • FK Transfer

    Transfer forward kinematic motion to a SOP-based skeleton

  • FLIP Source

    Creates a surface or density VDB for sourcing FLIP simulations.

  • Facet

    Controls the smoothness of faceting of a surface.

  • Filament Advect

    Evolves polygonal curves as vortex filaments.

  • File

    Reads, writes, or caches geometry on disk.

  • File Cache

    Writes and reads geometry sequences to disk.

  • File Merge

    Reads and collates data from disk.

  • Fillet

    Creates smooth bridging geometry between two curves or surfaces.

  • Filmbox FBX ROP output driver

  • Find Shortest Path

    Finds the shortest paths from start points to end points, following the edges of a surface.

  • Fit

    Fits a spline curve to points, or a spline surface to a mesh of points.

  • Fluid Compress

    Compresses the output of fluid simulations to decrease size on disk

  • Font

    Creates 3D text from Type 1, TrueType and OpenType fonts.

  • Force

    Uses a metaball to attract or repel points or springs.

  • Fractal

    Creates jagged mountain-like divisions of the input geometry.

  • Full Body IK

    Transfer a motion to a SOP-based skeleton using full-body inverse kinematics algorithm.

  • Fur

    Creates a set of hair-like curves across a surface.

  • Fuse

    Merges points.

  • Geometry nodes

    Geometry nodes live inside Geo objects and generate geometry.

  • Glue Cluster

    Adds strength to a glue constraint network according to cluster values.

  • Grain Source

    Generates particles to be used as sources in a particle-based grain simulation.

  • Graph Color

    Assigns a unique integer attribute to non-touching components.

  • Grid

    Creates planar geometry.

  • Groom Blend

    Blends the guides and skin of two grooms.

  • Groom Fetch

    Fetches groom data from grooming objects.

  • Groom Pack

    Packs the components of a groom into a set of named Packed Primitives for the purpose of writing it to disk.

  • Groom Switch

    Switches between all components of two groom streams.

  • Groom Unpack

    Unpacks the components of a groom from a packed groom.

  • Group

    Generates groups of points, primitives, edges, or vertices according to various criteria.

  • Group Combine

    Combines point groups, primitive groups, or edge groups according to boolean operations.

  • Group Copy

    Copies groups between two pieces of geometry, based on point/primitive numbers.

  • Group Delete

    Deletes groups of points, primitives, edges, or vertices according to patterns.

  • Group Expand

    Expands or shrinks groups of Edges, Points, Primitives, or Vertices.

  • Group Expression

    Runs VEX expressions to modify group membership.

  • Group Find Path

    Constructs groups for paths between elements.

  • Group Joints

    Group Joints on a SOP Rig.

  • Group Paint

    Sets group membership interactively by painting.

  • Group Promote

    Converts point, primitive, edge, or vertex groups into point, primitive, edge, or vertex groups.

  • Group Range

    Groups points and primitives by ranges.

  • Group Rename

    Renames groups according to patterns.

  • Group Transfer

    Transfers groups between two pieces of geometry, based on proximity.

  • Group by Lasso

    Groups points and primitives by lasso.

  • Group from Attribute Boundary

    Creates a group that includes the boundaries of the specified attribute.

  • Guide Advect

    Advects guide points through a velocity volume.

  • Guide Collide With VDB

    Resolves collisions of guide curves with VDB signed distance fields.

  • Guide Deform

    Deforms geometry with an animated skin and optionally guide curves.

  • Guide Groom

    Allows intuitive manipulation of guide curves in the viewport.

  • Guide Group

    Creates standard primitive groups used by grooming tools.

  • Guide Initialize

    Quickly give hair guides some initial direction.

  • Guide Mask

    Creates masking attributes for other grooming operations.

  • Guide Partition

    Creates and prepares parting lines for use with hair generation.

  • Guide Skin Attribute Lookup

    Looks up skin geometry attributes under the root point of guide curves.

  • Guide Tangent Space

    Constructs a coherent tangent space along a curve.

  • Guide Transfer

    Transfer hair guides between geometries.

  • Hair Card Generate

    Converts dense hair curves to a polygon card, keeping the style and shape of the groom.

  • Hair Clump

    Clumps guide curves together.

  • Hair Generate

    Generates hair on a surface or from points.

  • Hair Growth Field

    Generates a velocity field based on stroke primitives.

  • HeightField

    Generates an initial heightfield volume for use with terrain tools.

  • HeightField Blur

    Blurs a terrain height field or mask.

  • HeightField Clip

    Limits height values to a certain minimum and/or maximum.

  • HeightField Copy Layer

    Creates a copy of a height field or mask.

  • HeightField Crop

    Extracts a square of a certain width/length from a larger height volume, or resizes/moves the boundaries of the height field.

  • HeightField Cutout by Object

    Creates a cutout on a terrain based on geometry.

  • HeightField Distort by Layer

    Displaces a height field by another field.

  • HeightField Distort by Noise

    Advects the input volume through a noise pattern to break up hard edges and add variety.

  • HeightField Draw Mask

    Lets you draw shapes to create a mask for height field tools.

  • HeightField Erode

    Calculates thermal and hydraulic erosion over time (frames) to create more realistic terrain.

  • HeightField Erode Hydro

    Simulates the erosion from one heightfield sliding over another for a short time.

  • HeightField Erode Precipitation

    Distributes water along a heightfield. Offers controls for adjusting the intensity, variability, and location of rainfall.

  • HeightField Erode Thermal

    Calculates the effect of thermal erosion on terrain for a short time.

  • HeightField File

    Imports a 2D image map from a file or compositing node into a height field or mask.

  • HeightField Flow Field

    Generates flow and flow direction layers according to the input height layer.

  • HeightField Isolate Layer

    Copies another layer over the mask layer, and optionally flattens the height field.

  • HeightField Layer

    Composites together two height fields.

  • HeightField Layer Clear

    Sets all values in a heightfield layer to a fixed value.

  • HeightField Layer Property

    Sets the border voxel policy on a height field volume.

  • HeightField Mask by Feature

    Creates a mask based on different features of the height layer.

  • HeightField Mask by Object

    Creates a mask based some other geometry.

  • HeightField Mask by Occlusion

    Creates a mask where the input terrain is hollow/depressed, for example riverbeds and valleys.

  • HeightField Noise

    Adds vertical noise to a height field, creating peaks and valleys.

  • HeightField Output

    Exports height and/or mask layers to disk as an image.

  • HeightField Paint

    Lets you paint values into a height or mask field using strokes.

  • HeightField Patch

    Patches features from one heightfield to another.

  • HeightField Pattern

    Adds displacement in the form of a ramps, steps, stripes, Voronoi cells, or other patterns.

  • HeightField Project

    Projects 3D geometry into a height field.

  • HeightField Quick Shade

    Applies a material that lets you plug in textures for different layers.

  • HeightField Remap

    Remaps the values in a height field or mask layer.

  • HeightField Resample

    Changes the resolution of a height field.

  • HeightField Scatter

    Scatters points across the surface of a height field.

  • HeightField Slump

    Simulates loose material sliding down inclines and piling at the bottom.

  • HeightField Terrace

    Creates stepped plains from slopes in the terrain.

  • HeightField Tile Splice

    Stitches height field tiles back together.

  • HeightField Tile Split

    Splits a height field volume into rows and columns.

  • HeightField Transform

    Height field specific scales and offsets.

  • HeightField Visualize

    Visualizes elevations using a custom ramp material, and mask layers using tint colors.

  • Hole

    Makes holes in surfaces.

  • IK Chains

    Create and evaluate Two-Bone IK solvers on a SOP skeleton.

  • Inflate

    Deforms the points in the first input to make room for the inflation tool.

  • Instance

    Instances Geometry on Points.

  • Intersection Analysis

    Creates points with attributes at intersections between a triangle and/or curve mesh with itself, or with an optional second set of triangles and/or curves.

  • Intersection Stitch

    Composes triangle surfaces and curves together into a single connected mesh.

  • Invoke Compiled Block

    Processes its inputs using the operation of a referenced compiled block.

  • IsoOffset

    Builds an offset surface from geometry.

  • IsoSurface

    Generates an isometric surface from an implicit function.

  • Join

    The Join op connects a sequence of faces or surfaces into a single primitive that inherits their attributes.

  • Knife

    Divides, deletes, or groups geometry based on an interactively drawn line.

  • L-System

    Creates fractal geometry from the recursive application of simple rules.

  • LOP Import

  • Lattice

    Deforms geometry based on how you reshape control geometry.

  • Lidar Import

    Reads a lidar file and imports a point cloud from its data.

  • Line

    Creates polygon or NURBS lines from a position, direction, and distance.

  • MDD

    Animates points using an MDD file.

  • Magnet

    Deforms geometry by using another piece of geometry to attract or repel points.

  • Map Points

    Stores a reference on a point to a point in another geometry.

  • Mask by Feature

    Creates a point attribute "mask" based on visibility/lighting, letting you limit the effect of other nodes to areas that are visible, or facing a certain direction, or in shadow.

  • Match Axis

    Aligns the input geometry to a specific axis.

  • Match Size

    Resizes and recenters the geometry according to reference geometry.

  • Match Topology

    Reorders the primitive and point numbers of the input geometry to match some reference geometry.

  • Material

    Assigns one or more materials to geometry.

  • Measure

    Measures area, volume, or curvature of individual elements or larger pieces of a geometry and puts the results in attributes.

  • Merge

    Merges geometry from its inputs.

  • MetaGroups

    Defines groupings of metaballs so that separate groupings are treated as separate surfaces when merged.

  • Metaball

    Creates metaballs and meta-superquadric surfaces.

  • Mirror

    Duplicates and mirrors geometry across a mirror plane.

  • Mocap Import

    Parses and imports motion capture data as geometry.

  • MotionClip

    Converts a skeleton animation to a MotionClip

  • MotionClip Blend

    Blends the animation of one MotionClip on top of another

  • MotionClip Cycle

    Smoothly loops a section of a MotionClip

  • MotionClip Evaluate

    Evaluates a single frame of a MotionClip

  • MotionClip Extract

    Extracts the motion of joints over a set of frames from a MotionClip

  • MotionClip Pose Delete

    Removes the specified samples from the MotionClip

  • MotionClip Pose Insert

    Adds a new sample to a MotionClip containing the given pose

  • MotionClip Retime

    Adjusts the timing of a MotionClip

  • MotionClip Sequence

    Concatenates two MotionClips

  • MotionClip Update

    Update a MotionClip using the given point list

  • Mountain

    Displaces points along their normals based on fractal noise.

  • Muscle Capture

    Supports Muscle Deform by assigning capture weights to points based on distance away from given primitives

  • Muscle Deform

    Deforms a surface mesh representing skin to envelop or drape over geometry representing muscles

  • Name

    Creates a "naming" attribute on points or primitives allowing you to refer to them easily, similar to groups.

  • Normal

    Computes surface normal attribute.

  • Null

    Does nothing.

  • Object Merge

    Merges geometry from multiple sources and allows you to define the manner in which they are grouped together and transformed.

  • Object_musclerig@musclerigstrokebuilder

  • Object_riggedmuscle@musclestrokebuilder

    Assists the creation of a Muscle or Muscle Rig by allowing you to draw a stroke on a projection surface.

  • Ocean Evaluate

    Deforms input geometry based on ocean "spectrum" volumes.

  • Ocean Foam

    Generates particle-based foam

  • Ocean Source

    Generates particles and volumes from ocean "spectrum" volumes for use in simulations

  • Ocean Spectrum

    Generates volumes containing information for simulating ocean waves.

  • Ocean Waves

    Instances individual waveforms onto input points and generated points.

  • OpenCL

    Executes an OpenCL kernel on geometry.

  • Orientation Along Curve

    Computes orientations (frames) along curves.

  • Output

    Marks the output of a sub-network.

  • Pack

    Packs geometry into an embedded primitive.

  • Pack Points

    Packs points into a tiled grid of packed primitives.

  • Packed Disk Edit

    Editing Packed Disk Primitives.

  • Packed Edit

    Editing Packed Primitives.

  • Paint Color Volume

    Creates a color volume based on drawn curve

  • Paint Fog Volume

    Creates a fog volume based on drawn curve

  • Paint SDF Volume

    Creates an SDF volume based on drawn curve

  • Particle Fluid Surface

    Generates a surface around the particles from a particle fluid simulation.

  • Particle Fluid Tank

    Creates a set of regular points filling a tank.

  • Partition

    Places points and primitives into groups based on a user-supplied rule.

  • Path Deform

    Deforms geometry using the shape of a curve.

  • Peak

    Moves primitives, points, edges or breakpoints along their normals.

  • Planar Patch

    Creates a planar polygonal patch.

  • Planar Patch from Curves

    Fills in a 2d curve network with triangles.

  • Planar Pleat

    Deforms flat geometry into a pleat.

  • Platonic Solids

    Creates platonic solids of different types.

  • Point Cloud Iso

    Constructs an iso surface from its input points.

  • Point Deform

    Deforms geometry according to an arbitrary connected point mesh.

  • Point Generate

    Creates new points, optionally based on point positions in the input geometry.

  • Point Jitter

    Jitters points in random directions.

  • Point Relax

    Moves points with overlapping radii away from each other, optionally on a surface.

  • Point Replicate

    Generates a cloud of points around the input points.

  • Point Split

    Splits points shared by multiple vertices, optionally only if the vertices differ in attribute values.

  • Point Velocity

    Computes and manipulates velocities for points of a geometry.

  • Point Weld

    Merges points interactively.

  • Points from Volume

    Creates set of regular points filling a volume.

  • Poly Bridge

    Creates flat or tube-shaped polygon surfaces between source and destination edge loops, with controls for the shape of the bridge.

  • Poly Expand 2D

    Creates offset polygonal geometry for planar polygonal graphs.

  • Poly Extrude

    Extrudes polygonal faces and edges.

  • PolyBevel

    Creates straight, rounded, or custom fillets along edges and corners.

  • PolyCut

    Breaks curves where an attribute crosses a threshold.

  • PolyDoctor

    Helps repair invalid polygonal geometry, such as for cloth simulation.

  • PolyFill

    Fills holes with polygonal patches.

  • PolyFrame

    Creates coordinate frame attributes for points and vertices.

  • PolyLoft

    Creates new polygons using existing points.

  • PolyPatch

    Creates a smooth polygonal patch from primitives.

  • PolyPath

    Cleans up topology of polygon curves.

  • PolyReduce

    Reduces the number of polygons in a model while retaining its shape. This node preserves features, attributes, textures, and quads during reduction.

  • PolySoup

    Combines polygons into a single primitive that can be more efficient for many polygons

  • PolySpline

    The PolySpline SOP fits a spline curve to a polygon or hull and outputs a polygonal approximation of that spline.

  • PolySplit

    Divides an existing polygon into multiple new polygons.

  • PolyWire

    Constructs polygonal tubes around polylines, creating renderable geometry with smooth bends and intersections.

  • Pose Difference

    Compute the difference between point transforms on two SOP skeletons.

  • Pose Scope

    Assigns channel paths and/or pickscripts to geometry.

  • Pose-Space Deform

    Interpolates between a set of pose-shapes based on the value of a set of drivers.

  • Pose-Space Deform Combine

    Combine result of Pose-Space Deform with rest geometry.

  • Pose-Space Edit

    Packs geometry edits for pose-space deformation.

  • Pose-Space Edit Configure

    Creates common attributes used by the Pose-Space Edit SOP.

  • Primitive

    Edits primitive, primitive attributes, and profile curves.

  • Profile

    Extracts or manipulates profile curves.

  • Project

    Creates profile curves on surfaces.

  • Pyro Bake Volume

    Helps develop the volume look both for viewport display and rendering after the pyro solve.

  • Pyro Burst Source

    Creates points suitable for sourcing into pyro simulations to create explosions.

  • Pyro Post-Process

    Applies common post-processing effects to the results of Pyro solves.

  • Pyro Scatter from Burst

    Generates a cloud of points around the input points suitable for pyro trails and particle simulations.

  • Pyro Solver

    Runs a dynamic Pyro simulation.

  • Pyro Source

    Creates points for sourcing pyro and smoke simulations.

  • Pyro Source Spread

    Pyro Source Spread solves for the spreading of flame across a point cloud.

  • Pyro Trail Path

    Generates curves to use as trails for the Pyro Trail Source node.

  • Pyro Trail Source

    Creates points suitable for sourcing into pyro simulations to create trails for explosions.

  • Python

    Runs a Python snippet to modify the incoming geometry.

  • RBD Bullet Solver

    Runs a dynamic Bullet simulation.

  • RBD Cluster

    Combines fractured pieces or constraints into larger clusters.

  • RBD Configure

    Packs and creates attributes describing rigid body objects.

  • RBD Connected Faces

    Stores the primitive number and distance to the opposite face on the inside faces of fractured geometry.

  • RBD Constraint Properties

    Creates attributes describing rigid body constraints.

  • RBD Constraints From Curves

    Creates rigid body constraint geometry from curves drawn in the viewport.

  • RBD Constraints From Lines

    Creates rigid body constraint geometry from interactively drawn lines in the viewport.

  • RBD Constraints From Rules

    Creates rigid body constraint geometry from a set of rules and conditions.

  • RBD Convert Constraints

    Converts existing constraint prims into constraints with different anchor positions.

  • RBD Deform Pieces

    Deforms geometry with simulated proxy geometry.

  • RBD Disconnected Faces

    Detects when connected faces have become separated.

  • RBD Exploded View

    Visualize RBD fractured geometry merged with the proxy geometry, pushed out from the center to create an exploded view.

  • RBD Guide Setup

    Sets attributes on packed fragments for the RBD Guide DOP.

  • RBD I/O

    Packs RBD fractured geometry, saves them to disk, and loads them back again.

  • RBD Interior Detail

    Creates additional detail on the interior surfaces of fractured geometry.

  • RBD Material Fracture

    Fractures the input geometry based on a material type.

  • RBD Pack

    Packs RBD geometry, constraints, and proxy geometry into a single geometry.

  • RBD Paint

    Paints values onto geometry or constraints using strokes.

  • RBD Unpack

    Unpacks an RBD setup into three outputs.

  • RMan Shader

    Attaches RenderMan shaders to groups of faces.

  • ROP FBX Animation Output

    Export animation from geometry-based skeleton to an FBX file.

  • ROP FBX Character Output

    Export a skinned character with geometry-based skeleton to an FBX file.

  • ROP Geometry Output

  • Rails

    Generates surfaces by stretching cross-sections between two guide rails.

  • Ray

    Projects one surface onto another.

  • Re-Orient Joints

    Re-Orient Joints on a SOP Rig..

  • Refine

    Increases the number of points/CVs in a curve or surface without changing its shape.

  • Reguide

    Scatters new guides, interpolating the properties of existing guides.

  • Remesh

    Recreates the shape of the input surface using "high-quality" (nearly equilateral) triangles.

  • Repack

    Repacks geometry as an embedded primitive.

  • Reparent Joints

    Reparent Joints on a SOP Rig.

  • Resample

    Resamples one or more curves or surfaces into even length segments.

  • Rest Position

    Sets the alignment of solid textures to the geometry so the texture stays put on the surface as it deforms.

  • Retime

    Retimes the time-dependent input geometry.

  • Reverse

    Reverses or cycles the vertex order of faces.

  • Reverse Foot

    Creates a reverse foot set up for the given input skeleton.

  • Revolve

    Revolves a curve around a center axis to sweep out a surface.

  • Rewire Vertices

    Rewires vertices to different points specified by an attribute.

  • Rig Attribute VOP

    Runs a VOP network to modify geometry attributes on a KineFX rig.

  • Rig Attribute Wrangle

    Runs a VEX snippet to modify transform attribute values on a KineFX rig.

  • Rig Copy Transforms

    Attach the joints of a skeleton SOP to another, posed skeleton.

  • Rig Doctor

    Optimize and run checks on a SOP skeleton

  • Rig Match Pose

    Conform the rest poses of two skeletons in preparation for retargeting.

  • Rig Mirror Pose

    Mirror a SOP skeleton’s pose.

  • Rig Pose

    Pose and animate a SOP rig or skeleton.

  • Rig Python

    Runs a Python snippet to modify the incoming rig geometry.

  • Rig Stash Pose

    Store a static pose on a skeleton as a matrix point attribute.

  • Ripple

    Generates ripples by displacing points along the up direction specified.

  • Ripple

    Generates ripples by displacing points along the up direction specified.

  • Scatter

    Scatters new points randomly across a surface or through a volume.

  • Scatter and Align

    Scatters points across a surface with randomized scale and orientation attributes for use with Copy to Points.

  • Scene Character Export

    Export animation from a geometry-based character to the Scene (OBJ) context.

  • Scene Character Import

    Creates a geometry-based character with animation from the Scene (OBJ) context.

  • Script

    Runs scripts when cooked.

  • Sculpt

    Lets you interactively reshape a surface by brushing.

  • Sequence Blend

    Morphs though a sequence of 3D shapes, interpolating geometry and attributes.

  • Shape Diff

    Computes the post-deform or pre-deform difference of two geometries with similar topologies.

  • Shrinkwrap

    Computes the convex hull of the input geometry and moves its polygons inwards along their normals.

  • Skeleton

    Interactively create and edit geometry-based skeletons.

  • Skeleton Blend

    Blends two skeletons

  • Skeleton Mirror

    Modify an input skeleton by duplicating joints across a mirror plane.

  • Skin

    Builds a skin surface between any number of shape curves.

  • Sky

    Creates a sky filled with volumentric clouds

  • Smooth

    Smooths out (or "relaxes") polygons, meshes and curves without increasing the number of points.

  • Soft Peak

    Moves the selected point along its normal, with smooth rolloff to surrounding points.

  • Soft Transform

    Moves the selected point, with smooth rolloff to surrounding points.

  • Solid Fracture

    Creates a partition of a tetrahedral mesh that can be used for finite-element fracturing.

  • Solver

    Allows running a SOP network iteratively over some input geometry, with the output of the network from the previous frame serving as the input for the network at the current frame.

  • Sort

    Reorders points and primitives in different ways, including randomly.

  • Sphere

    Creates a sphere or ovoid surface.

  • Split

    Splits primitives or points into two streams.

  • Spray Paint

    Spray paints random points onto a surface.

  • Sprite

    A SOP node that sets the sprite display for points.

  • Stabilize Joint

    Removes jitter from the input animation and handles terrain snapping of joints.

  • Starburst

    Insets points on polygonal faces.

  • Stash

    Caches the input geometry in the node on command, and then uses it as the node’s output.

  • Stitch

    Stretches two curves or surfaces to cover a smooth area.

  • Stroke

    Low level tool for building interactive assets.

  • Subdivide

    Subdivides polygons into smoother, higher-resolution polygons.

  • Subnetwork

    The Subnet op is essentially a way of creating a macro to represent a collection of ops as a single op in the Network Editor.

  • Super Quad

    Generates an isoquadric surface.

  • Surfsect

    Trims or creates profile curves along the intersection lines between NURBS or bezier surfaces.

  • Sweep

    Creates a surface by sweeping a cross section curve along a spine curve.

  • Switch

    Switches between network branches based on an expression or keyframe animation.

  • Switch-If

    Switches between two network branches based on an expression or geometry test.

  • TOP Geometry

    Sends input geometry to a TOP subnet and retrieves the output geometry.

  • Table Import

    Reads a CSV file creating point per row.

  • Test Geometry: Crag

    Creates a rock creature, which can be used as test geometry.

  • Test Geometry: Pig Head

    Creates a pig head, which can be used as test geometry..

  • Test Geometry: Rubber Toy

    Creates a rubber toy, which can be used as test geometry.

  • Test Geometry: Shader Ball

    Creates a shader ball, which can be used to test shaders.

  • Test Geometry: Squab

    Creates a squab, which can be used as test geometry.

  • Test Geometry: Template Body

    Creates a template body, which can be used as test geometry.

  • Test Geometry: Template Head

    Creates a template head, which can be used as test geometry.

  • Test Geometry: Tommy

    Creates a soldier, which can be used as test geometry.

  • Test Simulation: Crowd Transition

    Provides a simple crowd simulation for testing transitions between animation clips.

  • Test Simulation: Ragdoll

    Provides a simple Bullet simulation for testing the behavior of a ragdoll.

  • Tet Conform

    Creates a tetrahedral mesh that conforms to a connected mesh as much as possible.

  • Tet Embed

    Creates a simple tetrahedral mesh that covers a connected mesh.

  • Tet Partition

    Partitions a given tetrahedron mesh into groups of tets isolated by a given polygon mesh

  • TimeShift

    Cooks the input at a different time.

  • Toon Shader Attributes

    Sets attributes used by the Toon Color Shader and Toon Outline Shader.

  • Topo Transfer

    Non-rigidly deforms a surface to match the size and shape of a different surface.

  • TopoBuild

    Lets you interactively draw a reduced quad mesh automatically snapped to existing geometry.

  • Torus

    Creates a torus (doughnut) shaped surface.

  • Trace

    Traces curves from an image file.

  • Trail

    Creates trails behind points.

  • Transform

    The Transform operation transforms the source geometry in "object space" using a transformation matrix.

  • Transform Axis

    Transforms the input geometry relative to a specific axis.

  • Transform By Attribute

    Transforms the input geometry by a point attribute.

  • Transform Pieces

    Transforms input geometry according to transformation attributes on template geometry.

  • Tri Bezier

    Creates a triangular Bezier surface.

  • TriDivide

    Refines triangular meshes using various metrics.

  • Triangulate 2D

    Connects points to form well-shaped triangles.

  • Trim

    Trims away parts of a spline surface defined by a profile curve or untrims previous trims.

  • Tube

    Creates open or closed tubes, cones, or pyramids.

  • USD Animation Import

    Imports a skeleton and animation from a UsdSkel character.

  • USD Character Import

    Imports the rest geometry, skeleton, and animation from a UsdSkel character.

  • USD Skin Import

    Imports skinned geometry from a UsdSkel character.

  • UV Autoseam

    Generates an edge group representing suggested seams for flattening a polygon model in UV space.

  • UV Brush

    Adjusts texture coordinates in the UV viewport by painting.

  • UV Edit

    Lets you interactively move UVs in the texture view.

  • UV Flatten

    Creates flattened pieces in texture space from 3D geometry.

  • UV Fuse

    Merges UVs.

  • UV Layout

    Packs UV islands efficiently into a limited area.

  • UV Pelt

    Relaxes UVs by pulling them out toward the edges of the texture area.

  • UV Project

    Assigns UVs by projecting them onto the surface from a set direction.

  • UV Quick Shade

    Applies an image file as a textured shader to a surface.

  • UV Texture

    Assigns texture UV coordinates to geometry for use in texture and bump mapping.

  • UV Transform

    Transforms UV texture coordinates on the source geometry.

  • UV Unwrap

    Separates UVs into reasonably flat, non-overlapping groups.

  • Unix

    Processes geometry using an external program.

  • Unpack

    Unpacks packed primitives.

  • Unpack Points

    Unpacks points from packed primitives.

  • Unpack USD

    Converts "packed USD" primitives into normal Houdini geometry.

  • VDB

    Creates one or more empty/uniform VDB volume primitives.

  • VDB Activate

    Activates voxel regions of a VDB for further processing.

  • VDB Activate SDF

    Expand or contract signed distance fields stored on VDB volume primitives.

  • VDB Advect

    Moves VDBs in the input geometry along a VDB velocity field.

  • VDB Advect Points

    Moves points in the input geometry along a VDB velocity field.

  • VDB Analysis

    Computes an analytic property of a VDB volumes, such as gradient or curvature.

  • VDB Clip

    Clips VDB volume primitives using a bounding box or another VDB as a mask.

  • VDB Combine

    Combines the values of two aligned VDB volumes in various ways.

  • VDB Diagnostics

    Tests VDBs for Bad Values and Repairs.

  • VDB Fracture

    Cuts level set VDB volume primitives into multiple pieces.

  • VDB LOD

    Build an LOD Pyramid from a VDB.

  • VDB Morph SDF

    Blends between source and target SDF VDBs.

  • VDB Occlusion Mask

    Create a mask of the voxels in shadow from a camera for VDB primitives.

  • VDB Points Delete

    Deletes points inside of VDB Points primitives.

  • VDB Points Group

    Manipulates the Internal Groups of a VDB Points Primitive.

  • VDB Potential Flow

    Computes the steady-state air flow around VDB obstacles.

  • VDB Project Non-Divergent

    Removes divergence from a Vector VDB.

  • VDB Renormalize SDF

    Fixes signed distance fields stored in VDB volume primitives.

  • VDB Resample

    Re-samples a VDB volume primitive into a new orientation and/or voxel size.

  • VDB Reshape SDF

    Reshapes signed distance fields in VDB volume primitives.

  • VDB Segment by Connectivity

    Splits SDF VDBs into connected components.

  • VDB Smooth

    Smooths out the values in a VDB volume primitive.

  • VDB Smooth SDF

    Smooths out SDF values in a VDB volume primitive.

  • VDB Topology to SDF

    Creates an SDF VDB based on the active set of another VDB.

  • VDB Vector Merge

    Merges three scalar VDB into one vector VDB.

  • VDB Vector Split

    Splits a vector VDB primitive into three scalar VDB primitives.

  • VDB Visualize Tree

    Replaces a VDB volume with geometry that visualizes its structure.

  • VDB from Particle Fluid

    Generates a signed distance field (SDF) VDB volume representing the surface of a set of particles from a particle fluid simulation.

  • VDB from Particles

    Converts point clouds and/or point attributes into VDB volume primitives.

  • VDB from Polygons

    Converts polygonal surfaces and/or surface attributes into VDB volume primitives.

  • VDB to Spheres

    Fills a VDB volume with adaptively-sized spheres.

  • Vellum Brush

    Interactive brushing of Vellum geometry in the viewport.

  • Vellum Configure Grain

    Configures geometry for Vellum Grain constraints.

  • Vellum Constraint Property

    Modifies common Vellum Constraint properties.

  • Vellum Constraints

    Configure constraints on geometry for the Vellum solvers.

  • Vellum Drape

    Vellum solver setup to pre-roll fabric to drape over characters.

  • Vellum I/O

    Packs Vellum simulations, saves them to disk, and loads them back again.

  • Vellum Pack

    Packs Vellum geometry and constraints into a single geometry.

  • Vellum Post-Process

    Applies common post-processing effects to the result of Vellum solves.

  • Vellum Reference Frame

    Ties Vellum points to a reference frame defined by moving geometry.

  • Vellum Rest Blend

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

  • Vellum Solver

    Runs a dynamic Vellum simulation.

  • Vellum Unpack

    Unpacks a Vellum simulation into two outputs.

  • Verify BSDF

    Verify that a bsdf conforms to the required interface.

  • Vertex

    Manually adds or edits attributes on vertices (rather than on points).

  • Visibility

    Shows/hides primitives in the 3D viewer and UV editor.

  • Visualize

    Lets you attach visualizations to different nodes in a geometry network.

  • Visualize Rig

    Visualize the transformations and parenting of a SOP skeleton

  • Volume

    Creates a volume primitive.

  • Volume Analysis

    Computes analytic properties of volumes.

  • Volume Arrival Time

    Computes a speed-defined travel time from source points to voxels.

  • Volume Blur

    Blurs the voxels of a volume.

  • Volume Bound

    Bounds voxel data.

  • Volume Break

    Cuts polygonal objects using a signed distance field volume.

  • Volume Compress

    Re-compresses Volume Primitives.

  • Volume Convolve 3×3×3

    Convolves a volume by a 3×3×3 kernel.

  • Volume FFT

    Compute the Fast Fourier Transform of volumes.

  • Volume Feather

    Feathers the edges of volumes.

  • Volume Merge

    Flattens many volumes into one volume.

  • Volume Mix

    Combines the scalar fields of volume primitives.

  • Volume Optical Flow

    Translates the motion between two "image" volumes into displacement vectors.

  • Volume Patch

    Fill in a region of a volume with features from another volume.

  • Volume Ramp

    Remaps a volume according to a ramp.

  • Volume Rasterize

    Rasterizes into a volume.

  • Volume Rasterize Attributes

    Samples point attributes into VDBs.

  • Volume Rasterize Curve

    Converts a curve into a volume.

  • Volume Rasterize Hair

    Converts fur or hair to a volume for rendering.

  • Volume Rasterize Particles

    Converts a point cloud into a volume.

  • Volume Rasterize Points

    Converts a point cloud into a volume.

  • Volume Reduce

    Reduces the values of a volume into a single number.

  • Volume Resample

    Resamples the voxels of a volume to a new resolution.

  • Volume Resize

    Resizes the bounds of a volume without changing voxels.

  • Volume SDF

    Builds a Signed Distance Field from an isocontour of a volume.

  • Volume Slice

    Extracts 2d slices from volumes.

  • Volume Splice

    Splices overlapping volume primitives together.

  • Volume Stamp

    Stamps volumes instanced on points into a single target volume.

  • Volume Surface

    Adaptively surfaces a volume hierarchy with a regular triangle mesh.

  • Volume Trail

    Computes a trail of points through a velocity volume.

  • Volume VOP

    Runs CVEX on a set of volume primitives.

  • Volume Velocity

    Computes a velocity volume.

  • Volume Velocity from Curves

    Generates a volume velocity field using curve tangents.

  • Volume Velocity from Surface

    Generates a velocity field within a surface geometry.

  • Volume Visualization

    Adjusts attributes for multi-volume visualization.

  • Volume Wrangle

    Runs a VEX snippet to modify voxel values in a volume.

  • Volume from Attribute

    Sets the voxels of a volume from point attributes.

  • Voronoi Adjacency

    Create a line segment between points with adjacent Voronoi cells

  • Voronoi Fracture

    Fractures the input geometry by performing a Voronoi decomposition of space around the input cell points

  • Voronoi Fracture Points

    Given an object and points of impact on the object, this SOP generates a set of points that can be used as input to the Voronoi Fracture SOP to simulate fracturing the object from those impacts.

  • Voronoi Split

    Cuts the geometry into small pieces according to a set of cuts defined by polylines.

  • Vortex Force Attributes

    Creates the point attributes needed to create a Vortex Force DOP.

  • Whitewater Source

    Generates volumes to be used as sources in a whitewater simulation.

  • Winding Number

    Computes generalized winding number of surface at query points.

  • Wire Blend

    Morphs between curve shapes while maintaining curve length.

  • Wire Capture

    Captures surfaces to a wire, allowing you to edit the wire to deform the surface.

  • Wire Deform

    Deforms geometry captured to a curve via the Wire Capture node.

  • Wire Transfer

    Transfers the shape of one curve to another.

  • Wireframe

    Constructs polygonal tubes around polylines, creating renderable geometry.

  • glTF ROP output driver