• Houdini, a procedure oriented 2D,3D graphic application, with built-in package for a lot of simulation operation.

Concept inside Houdini

• it is all about asset, anything is a asset, (tool, shelf, node, parameter)

• env file for environment setting

  HOUDINI_PATH = "$HOUDINI_PATH;X:/myPath/houdini/HFS/16;&"
  HOUDINI_OTLSCAN_PATH = "$HOUDINI_OTLSCAN_PATH;X:/myPath/houdini/HDA_Libs/otls;&"
  HOUDINI_TOOLBAR_PATH="$HOUDINI_TOOLBAR_PATH;X:/myPath/houdini/ToolBar/16;&"

• icon path

  icon format: svg or PNG_20x20_pixel
  custom icon should be in: HOUDINI_UI_ICON_PATH
    * $HOME/houdiniX.Y/config/Icons
    * $HOME/Library/Preferences/houdini/X.Y/config/Icons
  
  system icon is at
  houdini_19_app_path\houdini\config\Icons\icons.zip
  houdini_18_app_path\houdini\help\icons.zip

• start houdini with init script (optionally in full path)

  houdinifx.exe X:\myPath\123.py

• houdini start will run 123.py, new session will run 456.py, it will always run pythonrc.py in its search path.
• houdini python path environment variable “HOUDINI_PATH”

• Houdini project env variables

• list all configuration of houdini in Shell:

  hconfig -ap

• Rohan Dalvi on Vimeo: http://vimeo.com/rohandalvi
• Go Procedure on Vimeo: http://vimeo.com/goprocedural/channels
• PQ Houdini Tutorial on Vimeo: http://vimeo.com/channels/54102
• Flexible Muscle-Based Locomotion: http://vimeo.com/channels/proceduralism/79098420

• PySide/PyQt Custom GUI sample:
  • http://www.sidefx.com/ja/docs/houdini14.0/hom/cookbook/qt/
• HOM: Houdini Object Model API reference for data access in Houdini
  • http://www.sidefx.com/ja/docs/houdini14.0/hom/cookbook/

• Houdini is same node concept as Nuke when access objects in application, based on a root node “hou” to access object under it,
• in Maya.cmds, you are calling Maya to return the data of the object by object string name instead of the object itself
  • while OpenMaya api and PyMel in Maya is more like same node concept

• houdini digital asset is like a group of node functions and saved as a big single node, like Gizmo in nuke.
  • doc ref: https://www.sidefx.com/docs/houdini/assets/namespaces.html
  • Make Your Own Houdini HDAs: https://www.youtube.com/watch?v=0uCrncu6_cY
• HDA naming convention, (asset's internal name)
  • operator name: [namespace::]node_name[::version]
  • operator name with sub category: [namespace::]node_category/node_name[::version]
  • operate label: Node Name (as shown in menu)
• HDA appearance in menu category:
  • HDA asset's Type Properties panel > Interactive tab > Shelf Tools tab > Context tab > Tab submenu path: BigFolder/SubFolderLike
    • also optionally to check OBJ, SOP, DOP alike content type filter
• show HDA path info in panel
  • Window > Asset Manager : Configuration tab > asset definition toolbar = show always