Barycentric Morph Controller

This controller is automatically applied when a morph object is created in the Create/Geometry/Compound Objects/Morph Panel. Morph targets are selected and keys are created at different times to morph the original object into the shape of the Morph Targets. See the Morph help topic for more information on creating morphs.

The Barycentric Morph controller represents each key as a series of weights for all targets. One barycentric key represents a new object which is a blending of all targets.

You can adjust each morph key to various percentages of the available morph targets. This lets you create subtle adjustments in the animation.

You can add keys between existing morph keys. The added keys contain interpolated values for all targets.

To access the key properties dialog, enter Track View, select the Morph track, select one of its keys, and click the Properties button to display the Key Info dialog.

Reference

Barycentric Morph Controller Key Info dialog

Current Key: Specifies the current key that you’re adjusting.

Time: Specifies where, in time, the current key is placed.

Tension/Continuity/Bias: Adjusts the TCB parameters of the key spline interpolation.

TCB Spline: Displays the key interpolation spline.

Targets: Lists all morph targets for the object, along with the percentage of their influence at the current key. Below the window is the total percentage of all targets. You can select any target in this window, and then adjust its percentage of influence using the spinner at right.

Percentage: Sets the percentage of influence for the target selected in the list window. Note that percentage values can be negative as well as greater than 100 percent.

Constrain to 100%: Check this to limit total weight of all targets to 100 percent. As you increase or decrease the percentage of a selected target, the other targets adjust accordingly. The adjustment takes the form of balancing all of the target percentages so that their relative weights remain the same.

When this check box is clear, you can adjust the weight of each target without affecting the others, and create a total that’s greater or less than 100 percent. Totals greater than 100 percent cause the morph object to scale up in size, while totals less than 100 percent cause the morph object to scale down. Note that this check box is global, and not confined to a single key or track.

How To

To use the Barycentric Morph controller:

1. Load tut23_1.max (the “Achoo” morphing faces used in the tutorials).
2. Select the nearest face, and convert it into a Morph object.
3. Click the Pick Target button and, at frames 20, 40, 60, and 80, assign each of the remaining four faces that are behind the frontmost face, in that order. Your morph targets should be:

00      M_face

20      M_twitch 1

40      M_twitch 2

60      M_ahhh

80      M_chooo

4. Go to frame 100, select M_face in the Morph Targets list window, and click Create Morph Key.
5. If you’re concerned about power outages in your area, save the file at this point under a different name.

Next, access the Morph keys.

6. Open Track View, and then open and select the Morph track under face/Object(Morph).
7. Select the key dot at frame 0, and then right-click over it to display the Key Info dialog with the Barycentric Morph controls.
8. Set the key field in the Key Info dialog to Key 2, and then drag the time slider to frame 20 so you’re on the same frame as the key you’re adjusting.
9. The Targets list window shows that the M_twitch1 target is at 100 percent at this key, while all the other targets are at 0 percent. Let’s say you want to add a bit of the “ahhh” in the “ahhh-choo.” Here’s how:
10. Make sure the Constrain to 100% check box is selected.
11. Select M_ahhh in the Targets window.
12. Move the Percentage spinner up and down, creating positive and negative values while observing the morph object.

Higher percentage values add some of the open-mouthed expression, while negative values actually make the face collapse in on itself.

Continue experimenting at different keyframes. Try turning off the Constrain to 100% check box, and see how the object scales up or down when the total percentage is no 100. Try also adding a key between the existing keys, and adjusting its target percentages.