supercharge houdini with python - staffjonun/web/teaching/2009-tncg13/slides/sfxfo3... ·...

Supercharge Houdini with Python

Fredrik LimsäterPartner / CTOFido Stockholm

Monday, November 9, 2009

Lesson 01 - Crowd Animation System

Very impressive results.

This is the strength of HoudiniReact = 1 weekHoudini = 4 hours


Lesson 02 - Houdini + Python

Dependant on that you go through the self studiesmaterial and Example files in Houdini covering DOPsand Python



Create and setup a RBD simulation using nothing but Python scripts. Create the basic structure without opening Houdini. Then create the DOP simulation by using a custom shelf tool that you script. Finish off by setup another shelf tool that render the sequence for you



But why would you create something this way?

License issues/cost $10 000 vs. $1 500

Unique geometry cachefor each shot



Problems or stuck?• [email protected]• What’s not working, what have you tried?


http://www.sidefx.com


mailto:[email protected]

mailto:[email protected]

Houdini + Python

• docs.python.org/tutorial• http://localhost:48626/hom/intro• http://localhost:48626/hom/hou/• Houdini Learning Material

• HOM - Houdini Object Model• Accessing HOM• Hou Module• Simple Code examples

• Simple Dop setup example• Create RBD Objects• Shelf tools - Dop setup• Destroy it• Shelf tools - Render• Hython example




Houdini + Python

• HOM - Houdini Object Model• Lets you query information and control Houdini using python• Defines classes for the conceptual entities in Houdini

- nodes, parameters, keyframes, panes etc• Defines methods for manipulating entities

i.e. adding nodes , changing parameter values etc


Houdini + Python

How to access HOM• HOM can be accessed through the hou module• hou hooks directly into Houdini


Houdini + Python

Hou modulePython 2.5.4 (r254:67916, Jul 7 2009, 23:51:24) [GCC 4.2.1 (Apple Inc. build 5646)] on darwinHoudini 10.0.430 hou module imported.Type "help", "copyright", "credits" or "license" for more information.>>> import hou>>> hou<module 'hou' from '/Library/Frameworks/Houdini.framework/Versions/10.0.430/Resources/houdini/scripts/python/hou.pyc'>>>> dir(hou)['Attrib', 'Attrib_swigregister', 'BaseKeyframe', 'BaseKeyframe_swigregister', 'BoundingBox', 'BoundingBox_swigregister', 'Bundle', 'Bundle_swigregister', 'ButtonParmTemplate', 'ButtonParmTemplate_swigregister', 'ChopNode', 'ChopNode_swigregister', 'Color', 'Color_swigregister',...


Houdini + Python

Querying a node

>>> geo_node = hou.node("/obj/geo1")>>> geo_node<hou.ObjNode of type geo at /obj/geo1>>>> geo_node.path()'/obj/geo1'

Querying and setting node parameters

>>> tx=geo_node.parm("tx")>>> tx<hou.Parm tx in /obj/geo1>>>> tx.eval()0.0>>> tx.set(3.5)>>> tx.eval()3.5


Houdini + Python

Alt + Shift + P brings up the Python Shell in HoudiniGreat place to prototype your code / get feedback

Python Source Editor - Saved in the hip file (session)

Other places: shelf tools, Node parameters etc


Houdini + Python

Standalone Implementation

hython - python interpreter shipped with Houdini.Text based version of Houdini, automatically sets up the hou module

/opt/hfs10.0.243/bin/hyton

You can also use Linux’s Python interpreter


Houdini + Python

Code Examples

root = hou.node("/obj")geo = root.createNode("geo", "myGeoContainer")geo.moveToGoodPosition()

#delete default file nodefor child in geo.children():

child.destroy()

m = geo.createNode("merge", "collectSpheres")m.moveToGoodPosition()

sphere1 = geo.createNode("sphere", "mySphere")sphere1.moveToGoodPosition()sphere1.parm("tx").set("1")

sphere2 = geo.createNode("sphere", "mySphere")sphere2.moveToGoodPosition()sphere.2parm("tx").set("3")

m.insertInput(0,sphere1)m.insertInput(0,sphere2)m.setDisplayFlag(1)


supercharge houdini with python - staffjonun/web/teaching/2009-tncg13/slides/sfxfo3... ·...

Documents