# Poly Bridge geometry node

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

## Overview

This node builds a polygonal surface between edges loops in one edge selection or boundary loops of a primitive selection and another. The "bridge" can automatically blend between the source and destination, or you can the bridge follow a curve.

You can create open bridges between edges. The node will automatically use the component type you select.

You can create "tunnels" between surfaces.

The source and destination can have different number of components. The node will automatically compensate by adding triangles.

You can specify the shape of the bridge by attaching a curve to the second input and setting Spine shape to "Curve from second input".

You can control the width and twist along the bridge using ramps

You can treat adjacent edges/faces as individuals rather than as groups.

## How to

1. Select the edges or faces on one side of the gap you want to bridge.

2. In the Polygon tab, click Poly Bridge.

3. Select the edges or faces on the other side of the gap.

4. The node will often start with the wrong direction at one or both ends.

Turn Reverse on/off, and/or change the Depart to "Along" or "Opposite" at one or both ends to correct this.

## Multiple bridges

This node can build multiple bridges at once if you select multiple sources and destinations.

However it is usually easier to just use multiple PolyBridge nodes instead of trying to create multiple bridges at once. Consider using multiple nodes instead of creating multiple multiple bridges in a single node.

### Splitting groups

If you want to define multiple source loops with edges/faces that happen to be adjacent, they will just look like one thing to the node. You choose a point/edge Split group that divides adjacent faces/edges into separate groups.

(If you are bridging edges, you split with a point group. If you are bridging faces, you split with an edge group.)

In the image below, the yellow line is an edge group splitting the selected faces into two sources.

## Fixing mis-pairings

The node will sometimes guess wrong which points in the origin should match up with which points in the destination. In these cases you can shift the pairings, or specify one or more explicit pairings between points.

### Pairing shift

If the pairing looks mostly right except it’s "twisted" because the pairings picked by the node are "rotated" (off by a certain number of places), you can use the Default pairing shift parameter on the Pairing tab to correct it.

This won’t work if you're making multiple bridges and only one has the wrong pairings, because this parameter will shift them all. In that case you should use explicit pairings, or use multiple Poly Bridge nodes.

### Explicit pairings

Explicit pairings give the node hints toward the proper bridge shape.

You must specify the pairings using point numbers from the input geometry, not this node’s output. Unless you turn off Delete source primitives and Delete destination primitives, the point numbers will be different in the input and output. You can see the point numbers from the input using a display flag trick:

1. Turn on Display point numbers in the view toolbar to the right of the viewer.

2. In the network editor, select the Poly Bridge node, but put the display flag on the node connected to this node’s first input (that is, show the geometry prior to this node).

This lets you edit the parameters of the Poly Bridge in the parameter editor and see the bridge output in wireframe, while displaying the point numbers as they were in the input.

3. Pick a source and destination point that should be connected but aren’t, and note their point numbers.

4. In the Poly Bridge parameters, click the Pairing tab.

Under "Explicit pairs", click Add and enter the source and destination point numbers.

Explicit pairings appear in the bridge geometry highlighted in blue.

## Highlight colors

When the node is selected, it color codes certain parts of the bridge in the viewport.

 Green Source edges Red Destination edges Light green Bridge spine Blue Between explicitly paired points Magenta Boundary (unshared) edges on open bridges

## Footings

### Source

Group

The edges/faces at this end of the bridge. This can be the name of an edge/face group.

Divide Into

Whether to treat adjacent edges/faces as a group, or as individuals.

Split Group

When Divide into is "Connected components", all adjacent elements are treated as a single group. If you are doing multiple bridges and there edges/faces that are adjacent but you want to be separate groups, you can split them using this group. See splitting above.

Reverse

Pair the edges on this side in reverse order. Turn this on/off if this end of the bridge starts in the wrong direction or is twisted. The pair order affects direction, so if you change this, you might also need to change Depart.

Depart

Controls the initial direction of the bridge at this end. You can choose to go along or opposite the "loop normal" (which is not necessarily the surface normal), or set the direction manually (choose "Along" or "Opposite" and then "Explicit direction" and use the handle in the viewport to set the direction).

If you use an explicit direction, make sure to set this to "Along" or "Opposite". If it is set to "Auto using", the direction will flip unexpectedly as you manipulate the handle.

Loop normal/Explicit direction

Whether to use the default direction (the "loop normal") or manually set the direction using a handle in the viewport.

Direction

When the menu above is set to "Explicit direction", this is the initial direction of this end of the bridge. You can set this interactively using a handle in the viewport.

Magnitude

Scales the first row of polygons at this end of the bridge.

Source Stiffness

How much the bridge will follow the initial direction at this end before heading toward the other end.

### Destination

Group

The edges/faces at this end of the bridge. This can be the name of an edge/face group.

Divide Into

Whether to treat adjacent edges/faces as a group, or as individuals.

Split Group

When Divide into is "Connected components", all adjacent elements are treated as a single group. If you are doing multiple bridges and there edges/faces that are adjacent but you want to be separate groups, you can split them using this group. See splitting above.

Reverse

Pair the edges on this side in reverse order. Turn this on/off if this end of the bridge starts in the wrong direction or is twisted. The pair order affects direction, so if you change this, you might also need to change Depart.

Arrive

Controls the initial direction of the bridge at this end. You can choose to go along or opposite the "loop normal" (which is not necessarily the surface normal), or set the direction manually (choose "Along" or "Opposite" and then "Explicit direction" and use the handle in the viewport to set the direction).

If you use an explicit direction, make sure to set this to "Along" or "Opposite". If it is set to "Auto using", the direction will flip unexpectedly as you manipulate the handle.

Loop normal/Explicit direction

Whether to use the default direction (the "loop normal") or manually set the direction using a handle in the viewport.

Direction

When the menu above is set to "Explicit direction", this is the initial direction of this end of the bridge. You can set this interactively using a handle in the viewport.

Magnitude

Scales the first row of polygons at this end of the bridge.

Source Stiffness

How much the bridge will follow the initial direction at this end before heading toward the other end.

## Spine

Spine shape

The path the bridge takes between the source and destination.

Straight

Straight from the source to the destination.

Curved

Curve between the initial and final directions.

Curve From Second Input

Take the shape of a curve connected to this node’s second input.

### Divisions

Divisions

The number of rows of polygons in the bridge, not including Source divisions and Destination divisions below.

Source Divisions

Adds extra rows to the start of the bridge with the exact same topology as the source edges. This may be useful if the bridge has triangles and you don’t want them to touch the source edges.

Source Divisions

Adds extra rows to the end of the bridge with the exact same topology as the destination edges. This may be useful if the bridge has triangles and you don’t want them to touch the destination edges.

Spacing

Controls the spacing of the divisions along the bridge.

Uniform

Spaced equally.

Curvature Sensitive

Uses more polygons in high curvature areas and fewer polygons in straight areas.

### External spine

Available when Spine Shape (at the top of the tab) is "Curve From Second Input".

U Range

Lets you use a subset of the full curve, where `0` is the start of the curve and `1` is the end.

Positioning

How to relate the position of the external curve in world space to the bridge. The best option is to use "Start at source, end at destination" (the default) and adjust the curve shape to get the bridge you want.

As is

Use the exact world space position of the curve. This may be useful if you've drawn the curve "in place" exactly where you want the bridge. If you've drawn the curve "off to the side", do not use this option.

Start at Source, End at Destination

Acts like the external curve was snapped between the start and end of the bridge. Uses the start and end directions of the curve, ignoring the directions set on the Footings tab.

The rest of the options are not as useful. It’s usually easier to just adjust the curve shape.

Start at Source, End Along Source Direction

Translates the start point of the curve to the source and rotates it minimally to ensure the end point of the curve lies along the source departing direction. Then scales the spine by the the Source Magnitude amount.

End at Destination, Start Along Destination Direction

Translates the end point of the curve to the destination and rotates it minimally to ensure the start point of the curve lies along the destination arriving direction. Then scales the spine by the the Destination Magnitude amount.

Start at Source, Tangent to Source Direction

Translates the start point of the curve to the source and rotates it minimally to make it tangent at the start point to the source departure direction. Then scales the spine by the the Source Magnitude amount.

End at Destination, Tangent to Destination Direction

Translates the end point of the curve to the destination and rotates it minimally to make it tangent at end point to the destination arrival direction. Then scales the spine by the the Destination Magnitude amount.

Translate Start to Source

Translates the start point of the curve to the source. Then scales the spine by the the Source Magnitude amount.

Translate End to Destination

Translates the end point of the curve to the destination. Then scales the spine by the the Destination Magnitude amount.

Reverse Direction

Reverses the direction of the spine curve.

Axial Rotation

Rotates the spine curve around the line through its end points.

Source blending

How much to blend the start of the external curve with the source departure direction from the Footings tab.

Destination blending

How much to blend the end of the external curve with the destination arrival direction from the Footings tab.

### Sample points

Generate Spine Sample Points

Create points along the spine of the bridge, where the points correspond to divisions of the bridge. To get just these points, turn off Generate bridge mesh on the Bridge tab. This may be useful for highly technical solutions where you want to get the bridge path but generate the geometry yourself separately.

Group

Enter a name to put the sample points in a group. You can use this group name in later nodes to easily target just the sample points.

Tangent Attribute

Enter a name to create a vector attribute on the points containing the bridge tangent at each point.

Normal Attribute

Enter a name to create a vector attribute on the points containing the bridge normal at each point.

Binormal Attribute

Enter a name to create a vector attribute on the points containing the third axis direction (the cross-product of the tangent and normal) at each point.

## Bridge

### Bridge mesh

Generate Bridge Mesh

Turn this off to not generate the bridge. This might be useful if you just want the points from Generate spine sample points on the Spine tab.

Mesh Primitive Group

Enter a name to put the bridge polygons in this group. You can use this group name in later nodes to easily target just the bridge polygons.

Attach to Input Geometry at Source

Fuse (share points between) the source loop and the first row of the bridge. This is ignored if Clip start is greater than `0`.

Attach to Input Geometry at Destination

Fuse (share points between) the source loop and the first row of the bridge. This is ignored if Clip end is greater than `0`.

Clip Range

Clips the bridge at the start and end, where `0` is the start of the bridge and `1` is the end.

(If the the start clip is greater than the end clip, you will get a reversed bridge rather than no bridge.)

Miter Joints

When selected, the divisions are scaled along the spine bend directions to achieve better (mitered) joints around sharper turns.

### Input geometry

Keep Input Geometry

Pass the geometry in the input through along with the new bridge polygons. Turn this off to output only the bridge polygons.

Delete Source Primitives

If the source group is polygonal faces, remove them from the output. This is useful for automatically opening the ends of a "tunnel".

Delete Destination Primitives

If the destination group is polygonal faces, remove them from the output. This is useful for automatically opening the ends of a "tunnel".

### Local thickness

These parameters let you scale the width of the bridge along its length, creating pinches and/or bulges in the bridge.

Thickness Scale

Scales the values of the Thickness ramp and/or Thickness attribute.

Thickness Attribute

If Spine Shape is "Curve From Second Input" (on the Spine tab), use this attribute on the external curve to control the thickness of the bridge. This is multiplied by the Thickness scale and added to the thickness ramp.

Thickness Ramp

Controls the thickness of the bridge along its length. The horizontal axis represents the length of the bridge. Values of `0.5` do no scaling. Values less than `0.5` narrow the bridge. Values greater than `0.5` widen the bridge.

### Twist

Full-Turn Twists

The number of full twists to add to the bridge along its length.

Twist Scale

Scales the values of the Twist ramp and/or Twist attribute.

Twist Attribute

If Spine Shape is "External" (on the Spine tab), use this attribute on the external curve to control the twist of the bridge. This is multiplied by the Twist scale and added to the twist ramp.

Local Twist Ramp

Controls the twist of the bridge along its length. The horizontal axis represents the length of the bridge. Values of `0.5` represent no twist. Values less than `0.5` twist in one direction, values greater than `0.5` twist in the other direction.

## Pairing

Provides explicit controls over which points on the source edges connect to which points on the destination edges.

Interpolation

A technical parameter of the node’s internal algorithm. "Rotating frame" tends to be better for twisting bridges, but in practice there’s no good basis for choosing one or the other. You can try both and see if they make a difference for your bridge.

Implicit Pairing

A technical parameter of the node’s internal algorithm. Controls how the node pairs up points other than the initial pair and any explicit pairs. Changing this will often have no effect on the bridge.

Use Relative Edge Lengths

Pairings are done by matching each point to the opposite sides closest point in terms of proportional distances along the boundary loop from the explicit or default pairs.

Use Edge Counts

Pairings are done by matching the points based on the number of edges between them and the explicit or default pairs on the two loops.

Default Pairing Shift

Shifts the pairings between points. This can fix cases where the bridge is "twisted" because the pairings are off by one or more. See how to fix mispairing.

Explicit Pairs

Lets you manually specify that certain points in the source geometry should connect along the bridge to certain points in the destination geometry. Note that these are point numbers on the input geometry. See how to fix mispairing.

# Geometry nodes

• Removes elements while trying to maintain the overall appearance.

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

• Creates agent primitives.

• Adds new clips to agent primitives.

• Defines how agents' animation clips should be played back.

• Creates geometry describing possible transitions between animation clips.

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

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

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

• Writes agent definition files to disk.

• Edits properties of agent primitives.

• Adds a new layer to agent primitives.

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

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

• Provides simple proxy geometry for an agent.

• Creates parent-child relationships between agents.

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

• Adds new transform groups to agent primitives.

• Extracts geometry from agent primitives.

• Extracts geometry from agent primitives for a Vellum simulation.

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

• Creates a geometry group for Alembic primitives.

• Modifies intrinsic properties of Alembic primitives.

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

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

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

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

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

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

• Adds or edits user defined attributes.

• Deletes point and primitive attributes.

• Allows simple VEX expressions to modify attributes.

• Fades a point attribute in and out over time.

• Interpolates attributes within primitives or based on explicit weights.

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

• Adds noise to attributes of the incoming geometry.

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

• Promotes or demotes attributes from one geometry level to another.

• Generates random attribute values of various distributions.

• Fits an attribute’s values to a new range.

• Renames or deletes point and primitive attributes.

• Modifies point attributes based on differences between two models.

• Edits string attribute values.

• Copies, moves, or swaps the contents of attributes.

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

• Transfers attributes between two geometries based on UV proximity.

• Runs a VOP network to modify geometry attributes.

• Runs a VEX snippet to modify attribute values.

• Samples texture map information to a point attribute.

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

• Converts primitives for ODE and Bullet solvers.

• Computes lighting values within volume primitives

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

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

• Deletes primitives, points, edges or breakpoints.

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

• The start of a looping block.

• The start of a compile block.

• The end/output of a looping block.

• The end/output of a compile block.

• Supports Bone Deform by assigning capture weights to bones.

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

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

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

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

• Creates default geometry for Bone objects.

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

• Fractures the input geometry using cutting surfaces.

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

• Creates a cube or six-sided rectangular box.

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

• Records and caches its input geometry for faster playback.

• Closes open areas with flat or rounded coverings.

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

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

• Adjusts capture regions and capture weights.

• Lets you paint capture attributes directly onto geometry.

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

• Overrides the capture weights on individual points.

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

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

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

• Creates open or closed arcs, circles and ellipses.

• Transforms selected geometry into a circle.

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

• Helps clean up dirty models.

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

• Captures low-res simulated cloth.

• Deforms geometry captured by the Cloth Capture SOP.

• Creates a volume representation of source geometry.

• Fills a volume with a diffuse light.

• Applies a cloud like noise to a Fog volume.

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

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

• Creates geometry and VDB volumes for use with DOPs collisions.

• Adds color attributes to geometry.

• Adjust surface point normals by painting.

• Creates lines between nearby pieces.

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

• Creates simple geometry for use as control shapes.

• Converts geometry from one geometry type to another.

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

• Converts the input geometry into line segments.

• Polygonizes metaball geometry.

• Generates the oriented surface of a tetrahedron mesh.

• Converts sparse volumes.

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

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

• Decomposes the input geometry into approximate convex segments.

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

• Copies geometry and applies transformations to the copies.

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

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

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

• Deforms and animates a piece of geometry across a surface.

• Creates a surface around cross sections.

• Populates a crowd of agent primitives.

• Creates polygonal, NURBS, or Bezier curves.

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

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

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

• Imports scalar and vector fields from a DOP simulation.

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

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

• Runs a VEX snippet to deform geometry.

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

• Smooths out (or "relaxes") point deformations.

• Attempts to prevent collisions when deforming geometry.

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

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

• Measures distance between each point and a reference geometry.

• Measures distance of each point from a target.

• Divides, smooths, and triangulates polygons.

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

• Creates a curve based on user input in the viewport.

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

• Collapses edges and faces to their centerpoints.

• Sharpens edges by uniquing their points and recomputing point normals.

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

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

• Flips the direction of polygon edges.

• Cuts geometry along edges using guiding curves.

• Straightens selected edges.

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

• Edits points, edges, or faces interactively.

• Closes, opens, or clamps end points.

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

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

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

• Export transform attributes to object nodes.

• Computes the centroid of each piece of the geometry.

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

• Extrudes geometry along a normal.

• Extrudes surface geometry into a volume.

• Creates a surface or density VDB for sourcing FLIP simulations.

• Controls the smoothness of faceting of a surface.

• Evolves polygonal curves as vortex filaments.

• Reads, writes, or caches geometry on disk.

• Writes and reads geometry sequences to disk.

• Reads and collates data from disk.

• Creates smooth bridging geometry between two curves or surfaces.

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

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

• Compresses the output of fluid simulations to decrease size on disk

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

• Uses a metaball to attract or repel points or springs.

• Creates jagged mountain-like divisions of the input geometry.

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

• Merges points.

• Geometry nodes live inside Geo objects and generate geometry.

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

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

• Assigns a unique integer attribute to non-touching components.

• Creates planar geometry.

• Blends the guides and skin of two grooms.

• Fetches groom data from grooming objects.

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

• Switches between all components of two groom streams.

• Unpacks the components of a groom from a packed groom.

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

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

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

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

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

• Runs VEX expressions to modify group membership.

• Constructs groups for paths between elements.

• Sets group membership interactively by painting.

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

• Groups points and primitives by ranges.

• Renames groups according to patterns.

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

• Groups points and primitives by lasso.

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

• Advects guide points through a velocity volume.

• Resolves collisions of guide curves with VDB signed distance fields.

• Deforms geometry with an animated skin and optionally guide curves.

• Allows intuitive manipulation of guide curves in the viewport.

• Creates standard primitive groups used by grooming tools.

• Quickly give hair guides some initial direction.

• Creates masking attributes for other grooming operations.

• Creates and prepares parting lines for use with hair generation.

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

• Constructs a coherent tangent space along a curve.

• Transfer hair guides between geometries.

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

• Clumps guide curves together.

• Generates hair on a surface or from points.

• Generates a velocity field based on stroke primitives.

• Generates an initial heightfield volume for use with terrain tools.

• Blurs a terrain height field or mask.

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

• Creates a copy of a height field or mask.

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

• Creates a cutout on a terrain based on geometry.

• Displaces a height field by another field.

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

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

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

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

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

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

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

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

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

• Composites together two height fields.

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

• Sets the border voxel policy on a height field volume.

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

• Creates a mask based some other geometry.

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

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

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

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

• Patches features from one heightfield to another.

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

• Projects 3D geometry into a height field.

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

• Remaps the values in a height field or mask layer.

• Changes the resolution of a height field.

• Scatters points across the surface of a height field.

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

• Creates stepped plains from slopes in the terrain.

• Stitches height field tiles back together.

• Splits a height field volume into rows and columns.

• Height field specific scales and offsets.

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

• Makes holes in surfaces.

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

• Instances Geometry on Points.

• 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.

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

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

• Builds an offset surface from geometry.

• Generates an isometric surface from an implicit function.

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

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

• Creates fractal geometry from the recursive application of simple rules.

• Deforms geometry based on how you reshape control geometry.

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

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

• Animates points using an MDD file.

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

• Aligns the input geometry to a specific axis.

• Resizes and recenters the geometry according to reference geometry.

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

• Assigns one or more materials to geometry.

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

• Merges geometry from its inputs.

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

• Creates metaballs and meta-superquadric surfaces.

• Duplicates and mirrors geometry across a mirror plane.

• Displaces points along their normals based on fractal noise.

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

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

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

• Computes surface normal attribute.

• Does nothing.

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

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

• Deforms input geometry based on ocean "spectrum" volumes.

• Generates particle-based foam

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

• Generates volumes containing information for simulating ocean waves.

• Instances individual waveforms onto input points and generated points.

• Executes an OpenCL kernel on geometry.

• Computes orientations (frames) along curves.

• Marks the output of a sub-network.

• Packs geometry into an embedded primitive.

• Packs points into a tiled grid of packed primitives.

• Editing Packed Disk Primitives.

• Editing Packed Primitives.

• Creates a color volume based on drawn curve

• Creates a fog volume based on drawn curve

• Creates an SDF volume based on drawn curve

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

• Creates a set of regular points filling a tank.

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

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

• Creates a planar polygonal patch.

• Fills in a 2d curve network with triangles.

• Deforms flat geometry into a pleat.

• Creates platonic solids of different types.

• Constructs an iso surface from its input points.

• Deforms geometry on an arbitrary connected point mesh.

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

• Jitters points in random directions.

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

• Generates a cloud of points around the input points.

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

• Computes and manipulates velocities for points of a geometry.

• Merges points interactively.

• Creates set of regular points filling a volume.

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

• Creates offset polygonal geometry for planar polygonal graphs.

• Extrudes polygonal faces and edges.

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

• Breaks curves where an attribute crosses a threshold.

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

• Fills holes with polygonal patches.

• Creates coordinate frame attributes for points and vertices.

• Creates new polygons using existing points.

• Creates a smooth polygonal patch from primitives.

• Cleans up topology of polygon curves.

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

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

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

• Divides an existing polygon into multiple new polygons.

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

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

• Combine result of Pose-Space Deform with rest geometry.

• Packs geometry edits for pose-space deformation.

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

• Edits primitive, primitive attributes, and profile curves.

• Extracts or manipulates profile curves.

• Creates profile curves on surfaces.

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

• Runs a dynamic Pyro simulation.

• Creates points for sourcing pyro and smoke simulations.

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

• Runs a Python snippet to modify the incoming geometry.

• Runs a dynamic Bullet simulation.

• Combines fractured pieces or constraints into larger clusters.

• Packs and creates attributes describing rigid body objects.

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

• Creates attributes describing rigid body constraints.

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

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

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

• Converts existing constraint prims into constraints with different anchor positions.

• Deforms geometry with simulated proxy geometry.

• Detects when connected faces have become separated.

• Merges RBD fractured geometry with the proxy geometry and pushes it out from the center to create an exploded view.

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

• Creates additional detail on the interior surfaces of fractured geometry.

• Fractures the input geometry based on a material type.

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

• Paints values onto geometry or constraints using strokes.

• Unpacks an RBD setup into three outputs.

• Attaches RenderMan shaders to groups of faces.

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

• Projects one surface onto another.

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

• Scatters new guides, interpolating the properties of existing guides.

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

• Repacks geometry as an embedded primitive.

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

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

• Retimes the time-dependent input geometry.

• Reverses or cycles the vertex order of faces.

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

• Rewires vertices to different points specified by an attribute.

• Generates ripples by displacing points along the up direction specified.

• Generates ripples by displacing points along the up direction specified.

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

• Runs scripts when cooked.

• Lets you interactively reshape a surface by brushing.

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

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

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

• Builds a skin surface between any number of shape curves.

• Creates a sky filled with volumentric clouds

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

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

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

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

• Creates a simple tetrahedral mesh that covers a connected mesh.

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

• 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.

• Reorders points and primitives in different ways, including randomly.

• Creates a sphere or ovoid surface.

• Splits primitives or points into two streams.

• Spray paints random points onto a surface.

• A SOP node that sets the sprite display for points.

• Insets points on polygonal faces.

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

• Stretches two curves or surfaces to cover a smooth area.

• Low level tool for building interactive assets.

• Subdivides polygons into smoother, higher-resolution polygons.

• 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.

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

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

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

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

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

• Reads a CSV file creating point per row.

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

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

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

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

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

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

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

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

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

• Performs variations of a Delaunay Tetrahedralization.

• Cooks the input at a different time.

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

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

• Creates a torus (doughnut) shaped surface.

• Traces curves from an image file.

• Creates trails behind points.

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

• Transforms the input geometry relative to a specific axis.

• Transforms the input geometry by a point attribute.

• Transforms input geometry according to transformation attributes on template geometry.

• Creates a triangular Bezier surface.

• Refines triangular meshes using various metrics.

• Connects points to form well-shaped triangles.

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

• Creates open or closed tubes, cones, or pyramids.

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

• Adjusts texture coordinates in the UV viewport by painting.

• Lets you interactively move UVs in the texture view.

• Creates flattened pieces in texture space from 3D geometry.

• Merges UVs.

• Packs UV islands efficiently into a limited area.

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

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

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

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

• Transforms UV texture coordinates on the source geometry.

• Separates UVs into reasonably flat, non-overlapping groups.

• Processes geometry using an external program.

• Unpacks packed primitives.

• Unpacks points from packed primitives.

• Converts "packed USD" primitives into normal Houdini geometry.

• Creates one or more empty/uniform VDB volume primitives.

• Activates voxel regions of a VDB for further processing.

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

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

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

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

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

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

• Tests VDBs for Bad Values and Repairs.

• Cuts level set VDB volume primitives into multiple pieces.

• Build an LOD Pyramid from a VDB.

• Blends between source and target SDF VDBs.

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

• Deletes points inside of VDB Points primitives.

• Manipulates the Internal Groups of a VDB Points Primitive.

• Computes the steady-state air flow around VDB obstacles.

• Removes divergence from a Vector VDB.

• Fixes signed distance fields stored in VDB volume primitives.

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

• Reshapes signed distance fields in VDB volume primitives.

• Splits SDF VDBs into connected components.

• Smooths out the values in a VDB volume primitive.

• Smooths out SDF values in a VDB volume primitive.

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

• Merges three scalar VDB into one vector VDB.

• Splits a vector VDB primitive into three scalar VDB primitives.

• Replaces a VDB volume with geometry that visualizes its structure.

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

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

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

• Fills a VDB volume with adaptively-sized spheres.

• Configures geometry for Vellum Grain constraints.

• Configure constraints on geometry for the Vellum solvers.

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

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

• Packs Vellum geometry and constraints into a single geometry.

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

• Ties vellum points to a reference frame defined by moving geometry.

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

• Runs a dynamic Vellum simulation.

• Unpacks a Vellum simulation into two outputs.

• Verify that a bsdf conforms to the required interface.

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

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

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

• Creates a volume primitive.

• Computes analytic properties of volumes.

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

• Blurs the voxels of a volume.

• Bounds voxel data.

• Cuts polygonal objects using a signed distance field volume.

• Re-compresses Volume Primitives.

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

• Compute the Fast Fourier Transform of volumes.

• Feathers the edges of volumes.

• Flattens many volumes into one volume.

• Combines the scalar fields of volume primitives.

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

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

• Remaps a volume according to a ramp.

• Rasterizes into a volume.

• Samples point attributes into VDBs.

• Converts a curve into a volume.

• Converts fur or hair to a volume for rendering.

• Converts a point cloud into a volume.

• Converts a point cloud into a volume.

• Reduces the values of a volume into a single number.

• Resamples the voxels of a volume to a new resolution.

• Resizes the bounds of a volume without changing voxels.

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

• Extracts 2d slices from volumes.

• Splices overlapping volume primitives together.

• Stamps volumes instanced on points into a single target volume.

• Adaptively surfaces a volume hierarchy with a regular triangle mesh.

• Computes a trail of points through a velocity volume.

• Runs CVEX on a set of volume primitives.

• Computes a velocity volume.

• Generates a volume velocity field using curve tangents.

• Generates a velocity field within a surface geometry.

• Adjusts attributes for multi-volume visualization.

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

• Sets the voxels of a volume from point attributes.

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

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

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

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

• Computes generalized winding number of surface at query points.

• Morphs between curve shapes while maintaining curve length.

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

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

• Transfers the shape of one curve to another.

• Constructs polygonal tubes around polylines, creating renderable geometry.

• Assigns channel paths and/or pickscripts to geometry.