Gary Hanna


About Me

VFX Artist
United States of America


My Tutorials

obj-image Beginner
Game Friendly Character Rigs
obj-image Intermediate
Hair Cards for Game Meshes

Recent Forum Posts

Pose Library Errors April 15, 2018, 6:41 p.m.

So anyone know what these errors mean? One is with a stock rig by control MMB dragging to blend the poses. The other is a custom character rig with poses I set up as a test…I can't get custom built poses to input on the timeline, but can on the stock rigs…

Bone Mirroring - automate with Python? April 2, 2018, 1:36 p.m.

you can make a quick shelf tool for this

make a new shelf tool and pop this into the script tab:

# get the selection
nodes = hou.selectedNodes()

for node in nodes:
    y = node.parm("ry").eval() * -1
    z = node.parm("rz").eval() * -1

this will change the “ry” and “rz” values on any selected node


Bone Mirroring - automate with Python? April 1, 2018, 5:28 p.m.

Hello all,

I'm working on a tutorial for bone rigging for game meshes (stock houdini rigs/workflows on tutorials aren't game friendly). One part of the lesson is avoiding a -1 scale by manually mirroring bone nodes (the mirror tool in Houdini mirrors with a -1 scale which causes issues when sharing the rig with other programs).

Anyway I was wondering if there's a way to automate what I'm doing below, which is after copying the right side bones to the left, I multiply the bones' Y and Z axis by negative one to get a manual mirror while retaining a +1 scale. For the record, you CAN NOT freeze the transforms as the -1 scale Houdini applies is in the capture bone tab, not the transform tab.

I'm wondering if there's a way to automate this in Python. I do not know python but want to keep the graph CLEAN and free of for each loops and constraints and references to avoid problems when exporting to other software as that has been a source of frustration when exchanging Houdini rigs back and forth.

Would anyone know the code to create what I'm assuming is a for each loop with a * wildcard tageting bone nodes ending in _L, then create a variable for it's Y axis, create a variable for it's Z axis, then set the Y axis to the Y variable*-1, then set the Z axis to be the Z var *-1 ?

8 Minutes into the video is what I'm referring to…the link is set to start at 8 mins but isn't working.