Houdini Engine for Unity
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About Version


This is a completely new version of the Houdini Engine for Unity plug-in. It has now been officially released. This new version is written completely from the ground up for improved usability, updated feature set, and lightweight footprint in Unity projects.

Note that this plug-in supports Unity 2018.4 LTS and newer versions.



  • Loading HDA files (*.hda,*.otl,*.otllc,*.hdalc,*.otlnc,*.hdanc).
  • Most of the SOPs that generate polygonal geometry.
  • All Parameter types including ramps (see Parameters)
  • Houdini Materials.
  • Curve SOP and curve editing (see Curves).
  • Input nodes and asset connections (Unity mesh, HDA, terrain) (see Inputs).
  • Object instancing (see Object Instancers).
  • Packed primitives (see Packed Primitives).
  • Roundtrip support of material assignments and mesh names for input meshes.
  • Collision geometry generation via attribute (box, sphere, mesh).
  • Supports more than 65K triangles per mesh on Unity 2017.3+.
  • Houdini Engine SessionSync.
  • Bake as new standalone GameObject, and/or new prefab.
  • Bake Update existing standalone GameObject, and/or existing prefab.
  • Load, cook, and bake callbacks.
  • Connecting existing Unity materials and Substance materials via material attribute.
  • Connecting existing Unity script via attribute.
  • Play mode changes will be reverted after returning to Editor mode.
  • Undo in Unity will revert parameter changes and recook automatically.
  • Attribute Painting and Editing (for editable nodes) (see Painting and Editing Attributes).
  • Heightfields will be converted to Unity Terrain (see Terrain (Height Fields)).
  • Transformer handles (xform) (see Handles).
  • LOD Groups (see Level of Detail).
  • Custom input script hooks (see Custom Input Scripts).


The following will not be supported:

  • Animation Baking.
  • Option to Split geos by group (only collision and LOD groups are supported).
  • Splitting points by vertex attributes (vertices are split by default, but optionally can use points via HDA Options).
  • Play mode per-frame cooking.


The following are currently known limitations:

  • On system locales that use commas for decimals instead of dots, such as Spanish (es-ES), curves and other assets that use strings for floating point numbers will have parsing issues when using .Net 4.6+. To work around this, the plug-in sets the System.Threading.Thread.CurrentThread.CurrentCulture as CultureInfo.InvariantCulture. This can be disabled in Plugin Settings.
  • In Unity, after creating / loading an asset, immediately invoking Undo will not remove it from the scene.
  • Duplicating / Copy & Pasting an instantiated asset will not work via Unity's built-in mechanism. Instead use the Duplicate Asset button on the HDA itself.
  • Deleting a generated asset GameObject that has been saved in a Scene will not remove any generated texture files in Unity project.
  • Support for specifying Substance materials via attributes is not yet supported.