Houdini 20.5

Shelf tools

How to use and customize the icons on the shelf at the top of the main window.

On this page

Overview

The shelf gives you quick access to commonly used functions in Houdini.

  • Most tools create new nodes for you in the background.

  • Some items on the shelf and in the toolbox are more “actions” than “tools” – they do something immediately when you click them, and don’t enter into a “tool state” or show options on the operation controls toolbar.

  • Most tools will use the current selection if possible. Some tools will prompt you for one or more selections if the current selection is not relevant, or if it needs more information. For example, the Parent tool on the Modify shelf tab prompts you to select the child and then the parent.

    After you make a prompted selection, press Enter to finish the selection. (You can also press ⇧ Shift + or right-click and choose Accept selection).

  • Some tools have alternate action-like behavior when you hold ⌃ Ctrl and click them.

    You can usually quick-place the object created by a tool at the origin by ⌃ Ctrl-clicking the tool. For example, when you ⌃ Ctrl-click the Sphere tool, it immediately creates a sphere at the origin instead of asking you to place the sphere in the viewer.

    If you ⌃ Ctrl-click the light or camera tools, they create a light/camera from the current view, instead of asking you to place the new object.

  • Hold the mouse over an item on the shelf to see its label and a brief description of what it does. While the tooltip is open, press F1 to see the full help page for the item.

  • See how to customize the shelf.

Create

Box

Creates a cube or six-sided rectangular box.

Sphere

Creates a sphere or ovoid surface.

Tube

Creates open or closed tubes, cones, or pyramids.

Torus

Creates a torus (doughnut) shaped surface.

Grid

Creates planar geometry.

Line

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

Circle

Creates open or closed arcs, circles and ellipses.

Draw Curve

Creates a curve based on user input in the viewport.

Spray Paint

Spray paints random points onto a surface.

Platonic Solids

Creates platonic solids of different types.

Metaball

Creates metaballs and meta-superquadric surfaces.

File

Reads, writes, or caches geometry on disk.

Helix

Creates spirals and helices.

Quick Shapes

Creates different types of primitive geometry.

Modify

Combine

Merges the geometry of multiple objects into the last selected one.

Extract

Creates a second object from a selected object or selected components.

Mirror

Duplicates and mirrors geometry across a mirror plane.

Copy to Points

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

Duplicate

Copies geometry and applies transformations to the copies.

Align Components

Transforms an object, or inserts a Transform node in a geometry network, to align two faces on separate models.

Match Transform

Transform objects to match another.

Move Pivot to Center

Moves the pivot of an object to the center of the bounding box for that object.

Move Center to Pivot

Moves an object’s bounding box center to its pivot.

Freeze

Moves object level transforms into a Transform SOP at the geometry level.

Bake Animation

Bakes animation from object transforms and CHOP overrides.

Delete

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

Hide

Turns off the display flag for the selected object node.

Model

Boolean

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

Shatter

Shatters the input geometry into multiple pieces.

TopoBuild

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

Group

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

Polygon

TopoBuild

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

PolyBevel

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

Knife

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

Clip

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

Smooth

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

Curve from Edges

Converts the input geometry into line segments.

Deform

Mountain

Adds or generates noise in geometry attributes.

Waves

Creates an ocean like surface.

Ripple

Generates ripples by displacing points along the up direction specified.

Texture

UV Project

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

UV Edit

Lets you interactively move UVs in the texture view.

UV Fuse

Merges UVs.

UV Flatten

Creates flattened pieces in texture space from 3D geometry.

UV Pelt

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

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.

UV Smooth

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

Clear Texture Cache

Clears the texture cache, forcing textures to be reloaded.

Rigging

IK from Objects

(Deprecated) Allows you to build an IK bone rig (with or without a Twist Affector) from existing objects in the scene.

IK from Bones

(Deprecated) Allows you to build an IK bone rig (with or without a Twist Affector) from existing bone(s) in the scene.

Edit Capture Regions

Allows you to adjust the bone capture regions.

Edit Capture Weights

Individually modifies point capture weights using slider handles on bones or via a spreadsheet.

Edit Capture Blends

Allows you to adjust the blending of previously captured geometry in the Object Viewer.

Mirror Capture Weights

Applies capture weights from one side of a geometry object to another.

Paint Capture Layer

Lets you paint capture attributes directly onto geometry.

Delta Mush

Smooths out (or “relaxes”) point deformations.

Characters

Simple Biped

A simple and efficient animation rig with full controls.

Simple Female

A simple and efficient female character animation rig with full controls.

Simple Male

A simple and efficient male character animation rig with full controls.

Mocap Biped 1

A male character with motion captured animations.

Mocap Biped 2

A male character with motion captured animations.

Mocap Biped 3

A male character with motion captured animations.

Mocap Biped 3

A male character with motion captured animations.

Constraints

Parent Blend

Blends between parent objects.

Blend

Blends the positions and orientations of the current object transform with target objects.

Look At

Makes an object point at another object.

Follow Path

Animates an object along a curve.

Points

Constrains to points on geometry or point cloud.

Surface

Constrain to an exact point on the surface of geometry.

Transform Constraint

Apply a transform as a constraint with an optional pivot.

Lag

Makes one object lag behind another object.

Jiggle

Jiggles the position of an object based on the animation of another object.

Gamepad

Drive an object using a game controller device.

Toggle Constraint

Toggles Constraints on selected objects.

Bake Constraint

Bake Constraints on selected objects.

Delete Constraint

Delete Constraints on selected objects.

Hair Utils

Add Fur

Adds fur to a surface.

Create Empty Guide Groom

Creates a container object for guide curves.

Create Guides

Creates a guide curves from a skin geometry or manipulates the guides of another groom object.

Merge Groom Objects

Combines the guides and skin of multiple groom objects.

Deform Guides

Creates a Guide Deform object in the network.

Simulate Guides

Adds physics simulation to a set of guides.

Generate Hair

Generates hair based on a groom node object’s output.

Isolate Groom Parts

Hide and disable unselected parts of a groom for faster feedback.

Toggle Display

Turns the display flag of the Hair Generate object on and off.

Generate Hair Cards

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

Hair Card Texture

Creates textures to be applied to existing hair cards.

Guide Process

Initialize Guides

Gives the guides an initial direction.

Curve Advect

Advects curves using a vector field generated from curves drawn on the skin surface.

Groom

Creates a Guide Groom SOP ready to draw & brush curves.

Reguide

Interpolates guides between planted guides.

Set Guide Direction

Points guides in the direction of a vector.

Set Guide Length

Lengthens or shortens guide hairs.

Lift Guides

Lifts curves off the skin or flattens them against it.

Straighten Guides

Straightens the hair by bending each segment back so that it’s in the same direction as the previous segment.

Smooth Guides

Blends the shapes of the neighboring guides to create a smoother look.

Frizz Guides

Offsets the curve points along the guide hairs to create a frizzy look.

Bend Guides

Bends curves in a certain direction and by a certain angle.

Clump Guides

Creates bunches of guide hairs.

Part Guides

Lets you draw a parting line on the skin geometry.

Add White Hairs

Adds the required attribute to mark hairs as white hairs in the standard hair shader.

Terrain FX

Terrain: Hills

Sets up a preset height field network to generate hilly terrain. This is useful for learning how the terrain tools work together.

Terrain: Mountain

Sets up a preset height field network to generate a mountain terrain. This is useful for learning how the terrain tools work together.

Terrain: Valley

Sets up a preset height field network to generate valley terrain. This is useful for learning how the terrain tools work together.

Terrain: Moonscape

Sets up a preset height field network to generate lunar terrain. This is useful for learning how the terrain tools work together.

Terrain: Islands

Sets up a preset height field network to generate island terrain. This is useful for learning how the terrain tools work together.

Terrain: Canyon

Sets up a preset height field network to generate deep canyon terrain. This is useful for learning how the terrain tools work together.

Terrain: Dunes

Sets up a preset height field network to generate desert dune terrain. This is useful for learning how the terrain tools work together.

Simple FX

Simple Cloth

Configures SOP-based vellum cloth from geometry and collider.

Simple Softbody

Configures SOP-based vellum softbody from geometry and collider.

Simple Fracture

Fractures the input geometry based on a material type.

Simple Guided RBDs

Configures SOP-based bullet RBD fractured objects from geometry, collider, and guide geometry.

Simple Muzzle Flash

Creates a visible blast from the the muzzle of a firearm during shooting.

Simple Billowy Smoke

Creates thick cloud-like smoke rising from a spherical base.

Simple GPU Ground Explosion

Creates an explosion that can be fully simulated on the GPU.

Simple GPU Torch

Creates a torch fire that can be fully simulated on the GPU.

Simple Fireball

Creates a large rising and expanding explosion.

Simple Aerial Explosion

Creates an aerial explosion.

Simple Ground Explosion

Creates a large ground explosion.

Simple Shockwave

Creates a large rising and expanding explosion with a ground shockwave.

Simple Bonfire

Creates a bonfire simulation using the sparse pyro solver.

Simple Spreading Fire

Creates a fire simulation spreading across the surface of the selected object.

Volume

Volume

Builds an offset surface from geometry.

SDF Polys

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

SDF Particles

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

Volume Paint Color

Creates a color volume based on drawn curve

Volume Paint Fog

Creates a fog volume based on drawn curve

Volume Paint SDF

Creates an SDF volume based on drawn curve

Fog Points

Converts a point cloud into a volume.

Fog Particles

Converts a point cloud into a volume.

Fog Curve

Converts a curve into a volume.

Convert VDB

Converts sparse volumes.

Lights and Cameras

Camera

You can view your scene through a camera, and render from its point of view.

Distant Light

Creates or edits a USD Distant Light, representing a far-off light source such as the sun. Adds some useful Karma-specific attributes.

Environment Light

Environment Lights provide background illumination from outside the scene.

Stereo Camera

Provides parameters to manipulate the interaxial lens distance as well as the zero parallax setting plane in the scene.

VR Camera

Camera supporting VR image rendering.

Gamepad Camera

Drive a camera using a game controller device in first person perspective.

Collisions

Static Object

Creates a Static Object from SOP Geometry.

Deforming Object

Creates a DOPs collision object from deforming SOP Geometry.

Surface Collider

Create a Static Object from SOP Geometry pre-configured for interaction with cloth.

Ground Plane

Creates an infinite ground plane suitable for RBD, cloth, or wire simulations.

Particles

Fireworks

Emits multi-colored particles from a point, which simulates fireworks.

Location Particle Emitter

Emits particles from a point in all directions.

Source Particle Emitter

Emits particles from an object in all directions.

Replicate Particles

Generates particles from incoming particles.

Axis Force Particles

Calculates and applies a force around an axis.

Point Attract Particles

Attracts particles to points or curves.

Curve Attract Particles

Attracts particles to points or curves.

Curve Force Particles

Creates forces generated from a curve.

Metaball Force Particles

Applies forces according to metaballs.

Color Particles

Changes a particle’s diffuse color and/or alpha.

Drag Particles

Applies drag particles.

Fan Particles

Applies a conical fan wind to particles.

Flock Particles

Applies a flocking algorithm to particles.

Force Particles

Applies a directional force to particles.

Wind on Particles

Applies wind to particles.

Interact Particles

Applies forces between particles.

Collision Detect Particles

Detects and reacts to collisions.

Instance Geometry on Particles

Lets you instance geometry on particles.

Sprite Particles

Sets the sprite display for particles.

Vortex Filaments

Swirls particles based on the simulated drift of “filaments” represented by polylines.

Grains

Dry Sand

Creates a grain object from a piece of geometry.

Wet Sand

Creates a grain object from a piece of geometry, with a clumpy wet look.

Sand Box

Creates a patch of sand with a collision object which contains the sand.

RBD Grains

Fills an object with spheres and uses the Bullet solver to drive them.

Upres Sand

Takes each particle from your original simulation and replaces it with a cluster of new ones.

Granular Solid

Fills an object loosely with grains and creates constraints to hold it together into one object.

Granular Sheet

Fills the surface of an object with densely packed grains and makes constraints to hold them together.

Granular Strand

Fills grains along the edges of polygons, creating a beaded wire effect.

Auto-Sleep Particles

Allows grains to wake up and go to sleep based on the velocity of nearby particles.

Awaken By Geometry

Activates particles near animated geometry.

Slice

Slices a particle fluid across an arbitrary plane for distribution to a simulation farm.

Slice Along Line

Slices a particle fluid using a set number of slicing planes evenly spaced along a certain direction.

Distribute Particle Fluid

Distribute shelf tools set up an object’s sim network so it can be solved in parallel on a farm of multiple machines using HQueue.

Vellum

Surface Collider

Create a Static Object from SOP Geometry pre-configured for interaction with cloth.

Vellum Cloth

Configures vellum cloth from geometry and adds to current vellum simulation.

Vellum Hair

Configures vellum hair from geometry and adds to current vellum simulation.

Vellum Strut Softbody

Configures Vellum strut softbody from geometry and adds to current Vellum simulation.

Vellum Tetrahedral Softbody

Tetrahedralizes input geometry, configures it as a Vellum softbody, and adds it to current Vellum simulation.

Vellum Balloon

Configures vellum balloon from geometry and adds to current vellum simulation.

Vellum Grains

Configures Vellum grains from geometry and adds to current vellum simulation.

Rigid Bodies

RBD Objects

Creates one or more rigid bodies from SOP geometry.

RBD Hero Object

Creates an RBD Object from SOP Geometry.

RBD Glued Objects

Creates a number of rigid bodies from SOP geometry and glues them together.

RBD Instanced Objects

Creates a rigid body at each point of some source geometry, similarly to how the Copy SOP copies geometry onto points.

RBD Ragdolls

Adds agent primitives to a Bullet simulation.

RBD Grains

Fills an object with spheres and uses the Bullet solver to drive them.

RBD Convex Proxy

Creates a number of rigid bodies from SOP geometry, which use proxy geometry from a convex decomposition.

RBD Sphere Proxy

Creates a number of rigid bodies from SOP geometry, which use proxy geometry composed of adaptively-sized spheres.

RBD Fractured Object

Creates a number of RBD Objects from SOP Geometry. These individual RBD Objects are created from the geometry primitive groups.

Make Breakable

Automatically fractures an RBD object.

RBD Impacts

Stores filtered information about impacts on an RBD object. The shelf tool has no effect in the viewport, it just sets up nodes in the network to record the impact data.

Debris

Emits particles from the edges and surfaces of separating fractured rigid bodies.

RBD Auto Freeze

Automatically freezes RBD Objects that have come to rest.

RBD Pin Constraint

Constrains an object to a point in space using a pin-like connection.

RBD Cone Twist Constraint

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

RBD Slider Constraint

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

RBD Hinge Constraint

Constrains an object to a point in space using a hinge-like connection.

RBD Spring Constraint

Constrains an object to a point in space using a spring-like connection.

RBD Angular Constraint

Constrains the rotation an object so it does not rotate at all.

RBD Angular Spring Constraint

Constrains the rotation of an object so it attempts to rotate naturally, but bounces back to its original rotation.

RBD Parent Constraint

Changes the parent of a constraint from a point in space to a goal object.

Particle Fluids

FLIP Fluid from Object

Creates a FLIP Fluid Object from SOP Geometry.

FLIP Tank

Generates node networks to create a half-filled box of FLIP fluid material, with proper boundary conditions to contain the fluid in the box.

Emit Particle Fluid

Emits fluid into a FLIP simulation.

Sink from Objects

Absorbs smoke, fire, liquid, or particle fluid in a container.

Sculpted Particle Fluid

Calculates and creates particle fluid between the surface and container of fluid in a particle fluid simulation.

Crown Splash Particle Fluid

Creates a FLIP fluid simulation setup to create a crown splash.

Drip Particle Fluid

Creates a FLIP fluid simulation setup to create a dripping fluid effect.

Suction Fluid

Creates a suction force to guide particles fluids toward a target object.

Condensation

Creates a particle simulation to mimic condensation on geometry.

Make Viscous

Turns on the viscosity parameters of a FLIP Fluid.

Whitewater

Creates spray, foam, and churn based on an underlying FLIP fluid simulation.

Slice

Slices a particle fluid across an arbitrary plane for distribution to a simulation farm.

Slice Along Line

Slices a particle fluid using a set number of slicing planes evenly spaced along a certain direction.

Distribute Particle Fluid

Distribute shelf tools set up an object’s sim network so it can be solved in parallel on a farm of multiple machines using HQueue.

Viscous Fluids

Melt Object

Creates a melting object from geometry.

Lava From Object

Creates a lava object from geometry.

Emit Lava

Generates a continuous stream of hot lava from an object.

Heat Within Object

Turns an object into a source of heating when particles pass through.

Cool Within Object

Turns an object into a source of cooling when particles pass through.

Emit Steam On Collision

Emits steam when a hot fluid comes into contact with a collider.

Sink from Objects

Absorbs smoke, fire, liquid, or particle fluid in a container.

Slice

Slices a particle fluid across an arbitrary plane for distribution to a simulation farm.

Slice Along Line

Slices a particle fluid using a set number of slicing planes evenly spaced along a certain direction.

Distribute Particle Fluid

Distribute shelf tools set up an object’s sim network so it can be solved in parallel on a farm of multiple machines using HQueue.

Oceans

Small Ocean

Creates a small patch of ocean complete with a material and depth information.

Large Ocean

Creates a large ocean complete with a material and depth information.

Guided Ocean Layer

Creates a FLIP fluid simulation that simulates a thin layer of the ocean surface.

Wave Tank

Creates a FLIP fluid simulation from an underlying ocean surface.

Beach Tank

Creates a FLIP fluid simulation of a beach with continuous waves.

Flat Tank

Creates a FLIP fluid simulation of a flat tank with a boundary layer.

Ocean Flat Tank

Creates a FLIP fluid simulation from an underlying ocean surface.

Whitewater

Creates spray, foam, and churn based on an underlying FLIP fluid simulation.

Pyro FX

Sparse Billowy Smoke

Creates thick cloud-like smoke rising from a spherical base.

Sparse Fireball

Creates a large rising and expanding explosion.

Aerial Explosion

Creates an aerial explosion.

Ground Explosion

Creates a large ground explosion.

Shockwave

Creates a large rising and expanding explosion with a ground shockwave.

Bonfire

Creates a bonfire simulation using the sparse pyro solver.

Spreading Fire

Creates a fire simulation spreading across the surface of the selected object.

FEM

Hybrid Object

Creates an FEM Hybrid Object from SOP Geometry.

Surface Collider

Create a Static Object from SOP Geometry pre-configured for interaction with cloth.

Volume Collider

Create a Static Object from SOP Geometry pre-configured for interaction with cloth.

Constrain Points to Target Animation

Constrain a selection of points to animated target positions.

Attach Points to Target Object

Constrains regions within a FEM object to another FEM object.

Slide Points against Target Object

Constrains regions within a FEM object to another FEM object.

Constrain Region

Constrains regions within a FEM object to another FEM object.

Fuse Point Pairs

Connect pairs of points in a simulation.

Wires

Set Initial Pose

Sets the initial shape of a simulated wire object based on its current shape.

Glue Wire to Animation

Constraints a wire point to a certain position and direction.

Attach Wire to Surface

Creates soft body constraints between a set of points on a target object and the closest points on a goal object. This is useful for attaching wire to dynamics objects.

Wire Pin Constraint

Provides controls for setting up basic positional constraints for wire objects.

Wire Spring Constraint

Provides controls for setting up basic spring constraints for wire objects.

Wire Angular Constraint

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

Wire Angular Spring Constraint

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

Wire Glue Constraint

Constraints a wire point to a certain position and direction.

Attach Constraint to Rigid Body

Connects an existing soft body constraint to an RBD object.

Attach Constraint to Dynamics Point

Connects an existing soft body constraint to a point on a dynamic object.

Attach Constraint to Animation

Connects an existing soft body constraint to the object’s animation.

Detach Constraint

(Re)Connects an existing soft body constraint to a point in world space.

Delete Constraint

Deletes an existing soft body constraint.

Distribute

Distribute shelf tools set up an object’s sim network so it can be solved in parallel on a farm of multiple machines using HQueue.

Crowds

Agent

Creates an agent from a source character rig, FBX file, USD file, or LOP.

Add Clip

Adds an animation clip to an agent primitive.

Collision Layer

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

Configure Joints

Sets the rotation limits of an agent’s joints.

Populate

Creates an agent source geometry node to generate agents for a crowd simulation.

Paint Density

Allows you to paint areas of high and low crowd density on terrain to affect the random placement of agents.

Simulate

Sets up a crowd simulation network.

Terrain Foot Planting

Sets the selected geometry as the terrain for a crowd simulation.

Obstacle

Sets the selected static DOP object as an obstacle for agents in a crowd simulation.

Path

Sets agents in a crowd simulation to follow the selected curve.

Look At

Sets agents in a crowd simulation to look at the selected object.

Target Position

Guides agents towards a target position.

Agent Cam

Creates and attaches cameras to crowd agents to visualize their point of view.

Stadium Example

Creates an example stadium scene using the crowds tools.

Street Example

Creates an example street scene using the crowds tools.

Formation Example

Creates an example formation scene using the crowds tools.

Fuzzy Obstacles Example

Creates an example of using fuzzy logic for obstacle avoidance and path following.

Fuzzy Transition Example

Creates an example of using fuzzy logic for state transitions.

Ragdoll Run Example

Creates an example of using ragdolls in a crowd simulation.

Drive Simulation

New Simulation

Creates a new DOP Network.

Group Dynamic Objects

Creates simulation object groups.

Fluid Force

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

Wind Force

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

Magnet Force

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

Vortex Force

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

Subtopics

Using the shelf

  • Customize the shelf

    How to change the look of the shelf, change and rearrange its contents, and create your own shelf tools.

Technical

See also

Houdini 20.5

Getting started

Using Houdini

  • Geometry

    How Houdini represents geometry and how to create and edit it.

  • Copying and instancing

    How to use copies (real geometry) and instances (loaded or created at render time).

  • Animation

    How to create and keyframe animation in Houdini.

  • Digital assets

    Digital assets let you create reusable nodes and tools from existing networks.

  • Import and export

    How to get scene, object, and other data in and out of Houdini.

  • MPlay viewer

    Using Houdini’s stand-alone image viewer.

Character FX

  • Character

    How to rig and animate characters in Houdini.

  • Crowd simulations

    How to create and simulate crowds of characters in Houdini.

  • Muscles and tissue

    How to create and simulate muscles, tissue, and skin in Houdini.

  • Hair and fur

    How to create, style, and add dynamics to hair and fur.

  • Feathers

    How to create highly realistic and detailed feathers for your characters.

Dynamics

  • Dynamics

    How to use Houdini’s dynamics networks to create simulations.

  • Vellum

    Vellum uses a Position Based Dynamics approach to cloth, hair, grains, fluids, and softbody objects.

  • Pyro

    How to simulate smoke, fire, and explosions.

  • Fluids

    How to set up fluid and ocean simulations.

  • Oceans and water surfaces

    How to set up ocean and water surface simulations.

  • MPM

    How to simulate different types of solid materials (such as snow, soil, mud, concrete, metal, jello, rubber, water, honey, and sand).

  • Destruction

    How to break different types of materials.

  • Grains

    How to simulate grainy materials (such as sand).

  • Particles

    How to create particle simulations.

  • Finite elements

    How to create and simulate deformable objects

Pipeline

  • Executing tasks with PDG/TOPs

    How to define dependencies and schedule tasks using TOP networks.

  • HQueue

    HQueue is Houdini’s free distributed job scheduling system.

  • Houdini Engine

    Documents the Houdini Engine C, Python APIs, and Houdini Engine plugins

  • Machine Learning

    Houdini provides a platform for machine learning which supports synthetic data generation, preprocessing, training models, exporting trained models, and deploying trained models

Nodes

  • OBJ - Object nodes

    Object nodes represent objects in the scene, such as character parts, geometry objects, lights, cameras, and so on.

  • SOP - Geometry nodes

    Geometry nodes live inside Geo objects and generate geometry.

  • DOP - Dynamics nodes

    Dynamics nodes set up the conditions and rules for dynamics simulations.

  • VOP - Shader nodes

    VOP nodes let you define a program (such as a shader) by connecting nodes together. Houdini then compiles the node network into executable VEX code.

  • LOP - USD nodes

    LOP nodes generate USD describing characters, props, lighting, and rendering.

  • ROP - Render nodes

    Render nodes either render the scene or set up render dependency networks.

  • CHOP - Channel nodes

    Channel nodes create, filter, and manipulate channel data.

  • COP - Copernicus nodes

    COP nodes provide real-time image manipulation within a 3D space.

  • TOP - Task nodes

    TOP nodes define a workflow where data is fed into the network, turned into work items and manipulated by different nodes. Many nodes represent external processes that can be run on the local machine or a server farm.

  • APEX - APEX nodes

    APEX nodes provide operations for building up the functionality of APEX graphs, which are used in KineFX to create character rigs and perform other geometry manipulation.

Scene building, Karma rendering, Image processing

  • Solaris and Karma

    Solaris is the umbrella name for Houdini’s scene building, look development, and Karma rendering tools based on the Universal Scene Description (USD) framework.

  • Copernicus

    Houdini’s 2D and 3D GPU image processing framework.

  • Compositing

    Houdini’s compositing networks let you create and manipulate images such as renders.

Mantra rendering and shading

Reference

  • Menus

    Explains each of the items in the main menus.

  • Viewers

    Viewer pane types.

  • Panes

    Documents the options in various panes.

  • Windows

    Documents the options in various user interface windows.

  • Stand-alone utilities

    Houdini includes a large number of useful command-line utility programs.

  • APIs

    Lists all the reference documentation for the ways you can program Houdini.

  • Python scripting

    How to script Houdini using Python and the Houdini Object Model.

  • Expression functions

    Expression functions let you compute the value of parameters.

  • HScript commands

    HScript is Houdini’s legacy scripting language.

  • VEX

    VEX is a high-performance expression language used in many places in Houdini, such as writing shaders.

  • Properties

    Properties let you set up flexible and powerful hierarchies of rendering, shading, lighting, and camera parameters.

  • Galleries

    Pre-made materials included with Houdini.

  • Houdini packages

    How to write and combine multiple environment variable definition files for different plug-ins, tools, and add-ons.

  • hwebserver

    Functions and classes for running a web server inside a graphical or non-graphical Houdini session.