Say you’re creating poses for your character with stepped keys, and have created key poses on frames 1 and 10. You want to make a breakdown pose on frame 7, but you want it to favor the first pose by 70%. The following comparison shows how this would be accomplished both with and without tweenMachine.
| Manual Process | Tween Machine |
|---|---|
| Select all controls on the character | Select all controls on the character |
| Change interpolation on all keyframes to linear | Left-click on frame 7 in the timeline |
| Left-click on frame 3 in the timeline | Adjust a slider in the tweenMachine interface to -70 |
| Middle-click on frame 7 in the timeline | |
| Set a key | |
| Change interpolation on all keyframes to stepped |
If you’re not happy with the results, you’ve got a lot of steps to repeat if you’re doing it the manual way. With tweenMachine, you simply adjust the slider and see the results immediately. Better still, if you’ve created a custom set that controls the entire character, you can skip the first step and save even more time.
Will tweenMachine create perfect breakdown poses? Not likely, but it will get you closer to your goal a lot faster than other methods. You spend less time with busywork and more time making actual progress.
Tween Machine was originally developed by Justin Barrett and used extensively throughout the animation and visual effects industries for years.
Development was taken over by Alex Widener in February 2018.
| Contribution | Author |
|---|---|
| tweenMachine.mel/ tweenMachine.py | Justin S. Barrett |
| xml_lib.mel | J. Adrian Herbez |
| Maya Shelf Icon | Keith Lango |
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Animators: Do not copy the file listed directly above, as tweenMachine is in active development and will be for the next few weeks. Instead, go to the Releases tab above the files, and download version 3.0.0.
Version 3.1.0 will come out at some point and be a restructure/rewrite/with many new features and a new look. Please check back for updates.
Move the tweenMachine.py file to your default Maya scripts directory.
C:/Users/username/Documents/maya/version_number/scripts
Save the icon into the “prefs/icons” folder for the same Maya version.
C:/Users/username/Documents/maya/version_number/prefs/icon
Once everything is installed, open Maya. In the script editor, type the following in a Python tab:
import tweenMachine
tweenMachine.start()
Highlight the line, then select File–>Save Selected to Shelf to turn it into a shelf button. Use the Shelf Editor to
assign the icon to the shelf button.
Move the tweenMachine.py file to your default Maya scripts directory.
/Users/username/Library/Preferences/Autodesk/maya/version_number/scripts
Save the icon into the “prefs/icons” folder for the same Maya version.
/Users/username/Library/Preferences/Autodesk/maya/version_number/prefs/icon
Once everything is installed, open Maya. In the script editor, type the following in a Python tab:
import tweenMachine
tweenMachine.start()
Highlight the line, then select File–>Save Selected to Shelf to turn it into a shelf button. Use the Shelf Editor to
assign the icon to the shelf button.
Do all the same stuff wherever your maya scripts folder is. You can find it by entering the following in a Maya Script Editor:
import sys
for s in sys.path:
print(s)
And then find the maya/version_number/scripts/ folder and follow the same steps as above.
When running tweenMachine for the first time, it will open with a bare-bones interface. There’s a single slider labeled “Selected”, and a group of seven buttons below the slider. In this mode, tweenMachine operates only on selected objects. Click between two keys on the timeline, and adjust the “Selected” slider to create a new breakdown key. The values set for the new breakdown key will be biased toward the surrounding keys on the timeline based on how you set the slider. In the slider’s default position, the new keys will be exactly halfway between the surrounding keys. Slider values to the left will favor the new key toward the previous key, while values to the right will favor the next key. Clicking one of the buttons will set the slider to a preset value. If you wish, you can highlight individual channels in Maya’s channel box, and tweenMachine will only perform its work on those channels, leaving others untouched.
That covers the core operation of tweenMachine, but there are additional features available through various menu items. A full breakdown of all menu items is covered in the next section
The functions for all (currently available) tweenMachine menu items are as follows…
Options > Show
Contains Menu Bar and Label visibility toggles, plus radio buttons that let you select if you want to see the slider, the buttons, or both.
Options > Mode… > Window
Sets the interface to be a standard floating window.
Options > Mode… > Toolbar
Sets the interface to toolbar mode, allowing you to place it next to other Maya toolbars in the main window.
Options > Overshoot
Toggles “overshoot mode” for all sliders. By default, the range of all sliders is -100 to 100. When “overshoot mode” is active, the range of all sliders changes to -150 to 150. Using this mode allows you to create overshoot poses on the right end of the sliders in the 101-150 range, while using it in the -101 to -150 range on the left end effectively creates anticipation poses.
Options > Special Tick Color
Toggles the tick color used for keys added using the tweenMachine. When off (default), the standard tick color is used. When on, the “special” tick color is used.
The buttons below each set slider provide a quick way to set the slider to predictable values. By default they are set to mimic the style of pose favoring familiar to 2D animators. The center button is an exact halfway point between the two poses, and spreading out from the center on either side, the remaining buttons represent pose favoring by 1/3, 1/5, and 1/8 in their respective directions.By holding the mouse over any button, an annotation popup will appear showing the numerical value assigned to that button.
While the button values and colors are locked in this version (unless you manually tweak them), the Python version will eventually allow them to be easily customized.