This is a simple plug-in command to copy skin weights from one object to another with some significant restrictions: Download sjtCopySkinWeights

  1. The meshes must be exactly mirrors of each other vertex-number wise. This plugin simply uses the vertex numbers of the mesh so each vertex of object A must have a corresponding vertex on object B.
  2. The joint names must be somehow side-differentiated e.g. L_joint and R_joint or left_side_arm_JNT and right_side_arm_JNT or you must somehow be able to map one side of joint names to the other.

This has mostly been useful when dealing with hands, you skin one and then you have to copy the weights over, but sometimes maya does a lousy job. This plug-in is pretty much like going in the component editor and copying each value for each vertex between meshes (which would be insane to do by hand). Note: this is not a very fast script (I was trying to learn the Maya API while writing this) so give it some time to work through dense meshes. If you have questions or comments just either send me an email or comment below.


  1. Select the object with the correct weights.
  2. Select the object with the incorrect weights.
  3. Run the command e.g. ‘sjtCopySkinWeights -s “L_” -r “R_”’


This command accepts two arguments -search/-s and -replace/-r and each argument requires a string to follow it that tells the plugin how to map the right joint names to the left ones. Yes it works kind of backwards. The command first constructs a list of all the influences on the first object, then it goes over every vertex on the other object and tries to map it’s influences to the ones in the influence-list from the first object.


On one side the joints are called L_….._JNT and the other R_……_JNT the proper arguments for this command to work would be (MEL syntax):

sjtCopySkinWeights -s "L_" -r "R_"

(if no arguments are givien, this is the default search pattern) This would also have worked (since the search strings can be regular expressions):

sjtCopySkinWeights -s "L_" -r "^[rR]_"

This would allow the right side joints to be named either R_…._JNT or r_…._JNT Just remember the regular expression should go with the -r flag, the -s flag is just used to replace the match from the -r flag with.

Example file

To test the command immediately you can load up th test file included in the zip download ‘’. First try scrubbing in the timeline to see the difference in weighting. The right side (pCube1) bends in the middle but the left side(pCube2) does not. To copy the weights from pCube1 to pCube2 first load the plugin, select pCube1 then pCube2 and type (MEL syntax):


into the command line (or script editor) and then the weights will have been copied from pCube1 to pCube2. Voila.

Select constraining object

This is a tiny snippet I threw together today to speed up selecting the object that was controlling my selected object. In this case the object that was being controlled was a curve, but the constraining object (controlling the curve) was an invisible transform node, so instead of going through the hypergraph I wrote this:

import maya.cmds as mc
selection =
toSelect = []
for item in selection:
   constraint = mc.listConnections( item+'.parentInverseMatrix[0]', d=1, s=0,type='constraint')
   if constraint:
      constraint = constraint[0]
      src = mc.listConnections(constraint+'.target[0].targetParentMatrix', d=0, s=1)
      if src:

Note: this allows you to select multiple constrained objects and this will try and find the driving objects, this does not handle multiple constraints or anything fancy like that. Enjoy

What I learned today #5: Quicktime COM object’s volume range.

When setting the volume of a quicktime player through COM please keep in mind that the range is from 0-1 NOT 0-100 as I thought (since there doesn’t seem to be any good documentation about the QT COM interface). QT allows you to set the volume to 100 and you end up with painfully loud sound. So set your volume to 1 to allow people to enjoy their hearing for a new day.

What I learned today #4:Center Current Frame

When using Maya’s Dope Sheet and Graph Editor you sometimes want to quickly center the editors on the current active frame. You can do this by going ‘View’>’Center Current Frame’ - or - you can add these two commands to your hotkey editor and map that functionality to some spiffy hotkeys: For the Graph Editor: animCurveEditor -edit -lookAt currentTime graphEditor1GraphEd; For the Dope Sheet: dopeSheetEditor -edit -lookAt currentTime dopeSheetPanel1DopeSheetEd; For those who like this sort of stuff there is Cameron Fielding’s ‘Tap your timing’ - tip

What I learned today #3: Wrapping your paths in quotes!

Always always always remember wrapping your paths in quotes. I keep running into stuff I wrote break because someone saved a file with a space in it and I forgot to wrap the path in quotes. This works: blackwave.exe -d 50 superwave.wav This doesn’t: blackwave.exe -d 50 super 2.wav (two file arguments, ‘super’ and ‘2.wav’) To fix this: blackwave.exe -d 50 "super 2.wav" So remember: whenever you are using path rembemer the "\""+ variable + "\"" (or something else that suits your language)

What I learned today #2: Various definitions of TEMP

In Softimage on Windows, if you fetch the TEMP environment variable e.g. from witihn python (with the os.environ dictionary), you will get a different directory when you get the TEMP variable from outside Softimage. Outside Softimage you get: C:\Users\<username>\some\path\I\cannot\rembemer within it you get: C:\Users\<username>\some\path\I\cannot\rembemer\XSI_temp_### Just in case you wanted to write files to TEMP and read from them later.

What I learned today #1: profiling helps you make things run faster

After seeing an excellent post (as usual) on Hamish’s site about a profiling utility he wrote I decided to give it a try today, and man is this thing useful or what. It helped me find bottlenecks in two of my scripts today and I can only imagine how much of the user’s time it will save.

Something sketchy

These have been making their rounds on the internet the last few days, and rightly so, they are absolutely fantastic. Sketchy Duel: Sketchy Ice Cream: Sketchy Guard: Truly fantastic work. Simple, clear, freaking hillarious. - a fantastic python resource

I ran into Doug Hellmann’s site the other day And he an excellent collection of articles and examples for a bunch of modules from python’s standard library called Python Module of the Week. The one’s I’ve used and had no idea existed were configparser, optparser and the logging module. But there are many, many more there. Absolute gold for those of us who havent gone through every page of the documentation.

An even tinier update

Well, this place sure has been quiet for the last few months. Might have something to do with having a 14 month old son coupled with working on Thor. Recently I’ve mostly been making some handy tools for Maya. One thing I learned is that if you playblast from maya using the x264 codec you simply need to remux the file and package it in an mp4 container and then you got yourself a nice quicktime-playing h264 playblast. Very handy stuff. Busy times. Who knows when i’ll post something again. The supsense is probably unbearable. As always you can catch my slighly more frequent posts on twitter.