View source for Houdini (software)

{{short description|3D animation software}}
{{for|the chess engine|Houdini (chess)}}
{{Overly detailed|date=March 2014}}
{{Infobox software
| name = SideFX Houdini FX
| logo = Houdini3D icon.png
| screenshot = 
| caption = 
| developer = Side Effects Software Inc.
| released = 1.0 / {{Start date and age|1996|10|02}}
| latest release version = 20.5.370
| latest release date = {{Start date and age|2024|05|31}}<ref>{{cite web|url=https://www.sidefx.com/forum/topic/98113/|title=Houdini 20.5 Production Build updated to 20.5.370 | date=27 Sep 2024 | access-date= 2024-10-11}}</ref>
| latest preview version = 
| latest preview date = 
| programming language = [[C++]], [[Python (programming language)|Python]]
| operating system = [[Linux]], [[macOS]], [[Windows]]
| language = English
| genre = [[3D computer graphics]]
| license = [[Proprietary software|Proprietary]]
| website = {{URL|https://www.sidefx.com}}
}}

'''Houdini''' is a [[3D animation]] [[application software|software]] application developed by [[Toronto]]-based SideFX, who adapted it from the '''PRISMS''' suite of [[procedural generation]] software tools.

The procedural tools are used to produce different effects such as complex reflections, animations and particles system.<ref name=":0">{{cite web |title=Side Effects Software – 25 years on |url=https://www.fxguide.com/fxfeatured/side-effects-software-25-years-on/ |website=fxguide |date=27 February 2012}}</ref> Some of its procedural features have been in existence since 1987.<ref name=":0" />

Houdini is most commonly used for the creation of visual effects in film and television. It is used by major VFX companies such as [[Walt Disney Animation Studios]], [[Pixar]], [[DreamWorks Animation]], [[Double Negative (VFX)|Double Negative]], [[Industrial Light & Magic|ILM]], [[Moving Picture Company|MPC]], [[Framestore]], [[Sony Pictures Imageworks]], [[Illumination Studios Paris]], [[Scanline VFX]], [[Method Studios]] and [[The Mill (company)|The Mill]].<ref>{{Cite web | url=https://aristeksystems.com/blog/3d-modeling-soft-2021/#houdini| title=3D Modeling Software in 2021 | accessdate=2022-05-19}}</ref>

It has been used in many feature animation productions, including [[Walt Disney Animation Studios|Disney's]] feature films ''[[Fantasia 2000]]'', ''[[Frozen (2013 film)|Frozen]]'', ''[[Zootopia]]''<ref name=":1">{{Cite web|title=Disney Animation Studios {{!}} Zootopia {{!}} SideFX|url=https://www.sidefx.com/community/disney-animation-studios-zootopia/|access-date=2021-07-14|website=www.sidefx.com|language=en}}</ref> and ''[[Raya and the Last Dragon]]'';<ref>{{cite web|title= Raya and the Last Dragon <nowiki>|</nowiki> SideFX|url=https://www.sidefx.com/community/raya-and-the-last-dragon/ |access-date=2022-04-03}}</ref> the [[Blue Sky Studios]] film ''[[Rio (2011 film)|Rio]]'', and [[DNA Productions]]' ''[[The Ant Bully (film)|Ant Bully]]''.<ref>{{Cite web |date=2006-12-14 |title=Grid Engine User Stories ::: DNA Productions |url=http://gridengine.info/pages/profile-DNA-Productions |access-date=2022-05-22 |website= |archive-url=https://web.archive.org/web/20061214130304/http://gridengine.info/pages/profile-DNA-Productions |archive-date=14 December 2006 |url-status=dead}}</ref>

SideFX also publishes Houdini Apprentice, a limited version of the software that is free of charge for non-commercial use.

== Release history==
{| class="wikitable sortable mw-collapsible mw-collapsed"
|+
!Version
!Release Date
!Supported OSs
!Price of Full License (USD)
!Observations
|-
|1.0
|1996-OCT-02
|IRIX
|$9,500
|Houdini 1.0 at SIGGRAPH 1996
|-
|2.0
|1997-AUG-05
|[[IRIX]]
|
|
|-
|2.5
|1998-MAR-28
|IRIX, Windows NT
|
|[[Windows NT]] support
|-
|3.0
|1999-OCT-02
|IRIX, Windows NT
|
|
|-
|4.0
|2000-JUL-24
|IRIX, Windows NT, Linux<ref>{{cite web |title=Houdini: Magic Doesn't Just Happen {{!}} Linux Journal |url=https://www.linuxjournal.com/article/3522 |website=www.linuxjournal.com}}</ref><ref>{{cite web |title=REVIEWS: Houdini 4.0 {{!}} Computer Graphics World |url=https://www.cgw.com/Publications/CGW/2000/Volume-23-Issue-6-June-2000-/REVIEWS-Houdini-4-0.aspx |website=www.cgw.com}}</ref>
|$17,000
|[[Linux]] support
|-
|5.0
|2002-MAR-12
|IRIX, Windows NT, Linux, SunOS
|$16,000
|First version on SunOS<ref>{{cite web |title=Sun And Side Effects Software Unveil Houdini 3D For Solaris |url=https://www.hpcwire.com/2001/08/17/sun-and-side-effects-software-unveil-houdini-3d-for-solaris/ |website=HPCwire |date=17 August 2001}}</ref>
|-
|5.5
|2002-MAY-14
|IRIX, Windows NT, Linux, SunOS
|$16,000
|
|-
|6.0
|2003-MAY-08
|IRIX, Windows NT, Linux, SunOS
|
|
|-
|6.5
|2004-APR-16
|IRIX, Windows NT, Linux, SunOS
|
|(needs confirmation exact release date)
|-
|7.0
|2004-SEP-20
|Windows NT, Linux
|
|Dropped [[Silicon Graphics]] IRIX and SunOS
|-
|8.0
|2005-OCT-06
|Windows NT, Linux
|$17,000
|
|-
|9.0
|2007-SEP-20
|Windows NT, Linux
|
|New UI
|-
|9.1
|2008-JAN-30
|Windows NT, Linux
|
|
|-
|9.5
|2008-JUL-17
|Windows NT, Linux, macOS
|
|[[macOS]] support
|-
|10.0
|2009-APR-16
|Windows NT, Linux, macOS
|
|Pyro FX
|-
|11.0
|2010-JUL-27
|Windows NT, Linux, macOS
|$6,695
|Flip Fluids
|-
|12.0
|2012-MAR-01
|Windows NT, Linux, macOS
|
|Bullet RBDs
|-
|12.1
|2012-AUG-07
|Windows NT, Linux, macOS
|
|
|-
|12.5
|2013-MAR-14
|Windows NT, Linux, macOS
|
|[[OpenVDB|VDB]] support, Polysoups, Wrangle Nodes
|-
|13.0
|2013-OCT-31
|Windows NT, Linux, macOS
|
|FEM Solver, Packed Primitives
|-
|14.0
|2015-JAN-15
|Windows NT, Linux, macOS
|
|PBD Grain Solver, Crowd Tools
|-
|15.0
|2015-OCT-15
|Windows NT, Linux, macOS
|
|
|-
|15.5
|2016-MAY-19
|Windows NT, Linux, macOS
|
|
|-
|16.0
|2017-FEB-21
|Windows NT, Linux, macOS
|$6,995
|New Network Editor, Node Shapes
|-
|16.5
|2017-NOV-07
|Windows 7 SP1+, Linux, macOS 10.10.2+
|$6,995
|
|-
|17.0
|2018-OCT-10
|Windows 7 SP1+, Linux, macOS 10.11+
|
|Vellum
|-
|17.5
|2019-MAR-13
|Windows 7 SP1+, Linux, macOS 10.11+
|
|Procedural Dependency Graph
|-
|18.0
|2019-NOV-27
|Windows 8+, Linux, macOS 10.13+
|
|Solaris
|-
|18.5
|2020-OCT-17
|Windows 8+, Linux, macOS 10.13+
|
|KineFX
|-
|19.0
|2021-OCT-27
|Windows 8+, Linux, macOS 10.13+
|$6,995
|Karma, CFX
|-
|19.5
|2022-JUL-21
|Windows 8+, Linux, macOS 10.15+
|$6,995
|
|-
|20.0
|2023-NOV-8
|Windows 8.1+, Linux, macOS 11+
|$6,995
|KarmaXPU, APEX
|-
|20.5
|2024-JUL-10
|Windows 10+, Linux, macOS 11+
|
|Copernicus
|}

==Features==
[[File:Houdini Engine Software.png|thumb|right|Screenshot from Houdini]]
Houdini covers all the major areas of 3D production, including these:

* Modeling – All standard geometry entities including Polygons, (Hierarchical) [[Non-uniform rational B-spline|NURBS]]/[[Bézier Curve]]s/Patches & Trims, [[Metaballs]]
* Animation – Keyframed animation and raw channel manipulation (CHOPs), [[motion capture]] support
* Rigging - proprietary KineFX and APEX systems
* Particles
* Dynamics – [[rigid body dynamics|Rigid Body Dynamics]], [[fluid dynamics|Fluid Dynamics]], Wire Dynamics, [[cloth modeling|Cloth Simulation]], [[Crowd simulation]].
* Lighting – node-based shader authoring, lighting and re-lighting in an IPR viewer
* Rendering – Houdini ships with SideFX's rendering engines Mantra and Karma; Houdini Indie licence and up support 3rd party rendering engines, such as [[RenderMan (software)|Renderman]], Octane, Arnold, Redshift, [[V-Ray|V-ray]], and Maxwell (soon).
* Volumetrics – With its native CloudFx and PyroFx toolsets, Houdini can create clouds, smoke and fire simulations.
* Compositing – full compositor of floating-point deep (layered) images.
* Plugin Development – development libraries for user extensibility.

Houdini is an open environment and supports a variety of scripting APIs. [[python (programming language)|Python]] is increasingly the scripting language of choice for the package, and is intended to substitute its original C Shell-like scripting language, [[HScript]]. However, any major scripting languages which support socket communication can interface with Houdini.

== Tools ==
===Operators===
Houdini's procedural nature is found in its operators. Digital assets are generally constructed by connecting sequences of operators (or '''OPs'''). This proceduralism has several advantages:  it allows users to construct highly detailed geometric or organic objects in comparatively very few steps;  it enables and encourages non-linear development;  and new operators can be created in terms of existing operators, a flexible alternative to non-procedural scripting often relied on in other packages for customisation. Houdini uses this procedural generation in production of [[texture mapping|textures]], [[shader]]s, [[particle system|particles]], "channel data" (data used to drive animation), [[rendering (computer graphics)|rendering]] and [[compositing]].

Houdini's operator-based structure is divided into several main groups:
*OBJs – nodes that pass transform information (Traditionally these contain SOPs.)
*SOPs – Surface Operators –  for procedural modelling.
*POPs – Particle Operators – used to manipulate [[Particle system|particles systems]].
*CHOPs – Channel Operators – for procedural animation and audio manipulation.
*COPs – Composite Operators – used to perform compositing on footages.
*DOPs – Dynamic Operators – for dynamic simulations for fluids, cloth, rigid body interaction etc.
*SHOPs – Shading Operator – for representing a dozen or more different shading types for several different renderers.
*ROPs – [[Rendering (computer graphics)|render]] operators – for building networks to represent different render passes and render dependencies.
*VOPs – VEX operators – for building nodes of any of the above types using a highly optimized SIMD architecture.
*TOPs - Task Operators<ref>{{Cite web|url=https://vimeo.com/322225534|title=Houdini 17.5 Launch Event|date=8 March 2019}}</ref>
*LOPs - Lighting Operators - for generating USD describing characters, props, lighting, and rendering.

Operators are connected together in networks. Data flows through, manipulated by each operator in turn. This data could represent 3D [[geometry]], [[bitmap]] images, particles, [[dynamics (mechanics)|dynamics]], [[shader]] [[algorithm]]s, [[animation]], [[Sound|audio]], or a combination of these. This [[node graph architecture]] is similar to that employed in node-based [[Compositing software|compositors]] such as [[Shake (software)|Shake]] or [[Nuke (software)|Nuke]].

Complex networks can be grouped into a single [[meta-operator]] node which behaves like a class definition, and can be instantiated in other networks like any compiled node. In this way users can create their own sophisticated tools without the need for programming. In this way Houdini can be regarded as a highly interactive visual programming toolkit which makes programming more accessible to artists.

Houdini's set of tools are mostly implemented as operators. This has led to a higher learning curve than other comparable tools. It is one thing to know what all the nodes do – but the key to success with Houdini is understanding how to represent a desired creative outcome as a network of nodes. Successful users are generally familiar with a large repertoire of networks (algorithms) which achieve standard creative outcomes. The overhead involved in acquiring this repertoire of algorithms is offset by the artistic and algorithmic flexibility afforded by access to lower level building blocks with which to configure shot element creation routines. In large productions, the development of a procedural network to solve a specific element creation challenge makes automation trivial. Many studios that use Houdini on large feature effects, and feature animation projects develop libraries of procedures that can be used to automate generation of many of the elements for that film with almost no artist interaction.

Also unique to Houdini is the range of [[input/output|I/O]] '''OPs''' available to animators, including [[MIDI]] devices, raw files or [[Transmission Control Protocol|TCP]] connections, audio devices (including built-in [[phoneme]] and [[Pitch (music)|pitch]] detection), [[mouse (computing)|mouse]] [[cursor (computers)|cursor]] position, and so on.  Of particular note is Houdini's ability to work with audio, including sound and music synthesis and spatial 3D sound processing tools. These operators exist in the context called "CHOPs" for which Side Effects won a Technical Achievement Academy Award in 2002.

VEX (Vector Expression) is one of Houdini's internal languages. It is similar to the [[Renderman Shading Language]]. Using VEX a user can develop custom SOPs, POPs, shaders, etc. The current implementation of VEX utilizes [[SIMD]]-style processing.

==Rendering==
Houdini is bundled with a production-class renderer, Mantra, which had many similarities to [[RenderMan (software)|RenderMan]] in its scope and application in its initial incarnation. [[Micropolygon]] rendering is supported, allowing high-quality displacement operations as well as traditional scan-line and raytracing modes. Shaders are scriptable and composed in their VEX language, or by using VOPs; their node-based interface to programming VEX. Mantra (as does Houdini itself) also supports point-clouds, which can be similar in application as brickmaps in Renderman. This allows more complicated light interactions, such as sub-surface scattering and ambient occlusion, to be produced with lower computational overhead. Mantra can perform extremely fast [[volume rendering]], and also physically based [[path tracing|path-tracing]] – a technique which attempts to more accurately model the physical interactions of light and materials.

==TouchDesigner==
''Derivative Inc.'' is a spin-off of Side Effects Software that markets a derivative of Houdini called [[TouchDesigner]].  Tailored toward real-time [[OpenGL]]-generated animation, it was used on rock group [[Rush (band)|Rush]]'s 30th-anniversary tour to produce dynamic graphics driven directly by the musicians.<ref>{{cite web |title=Rush 30th Anniversary Tour |url=https://derivative.ca/community-post/rush-30th-anniversary-tour |website=Derivative |language=en |date=15 October 2004}}</ref> [[TouchDesigner]] was also used by Xite Labs (formerly V Squared Labs) to create live visuals for [[Amon Tobin]]'s [[ISAM (album)|ISAM]] installation tour.<ref>{{cite web |title=Amon Tobin ISAM WORLD TOUR |url=https://xitelabs.com/portfolio/amon-tobin/ |website=XiteLabs |language=en |date=1 August 2021}}</ref>

== Production ==
Notable works in which Houdini was used include the 1997 ''[[Contact (1997 American film)|Contact]]'' movie and more recent 2016 ''[[Zootopia]].<ref name=":0" />''<ref name=":1" />

==See also==
{{sort list|asc|2=
* [[Blender (software)|Blender]]
* [[Silicon Graphics]] Inc
* [[IRIX]] OS
* [[Autodesk Maya]]
* [[Softimage 3D]]
* [[Cinema 4D]]
}}

==References==
{{reflist | 30em}}

==External links==
* [https://www.sidefx.com/ SideFX Software], Makers of Houdini

{{Compositing Software}}
{{Animation editors}}
{{3D software}}

{{DEFAULTSORT:Houdini (Software)}}
[[Category:3D graphics software]]
[[Category:IRIX software]]
[[Category:1996 software]]
[[Category:3D animation software]]
[[Category:3D computer graphics software for Linux]]
[[Category:Proprietary commercial software for Linux]]
[[Category:Motion graphics software for Linux]]