Tutorial 4: Animating Bipeds interacting with Objects
When a biped needs to pick something up, carry something or put something down, you can use the Link Controller to animate the biped, then let the biped's hand animation control the movement of the object.
In this lesson, a character picks up, carries and puts down a briefcase.
Play the animation.
The biped picks up, carries and sets down a heavy invisible object with a handle.
Select Bip01 R Hand.
Turn on Key mode and move through the keys.
There is a key at frame 56, where the biped picks up the briefcase. The biped carries the briefcase until frame 228.
You'll use these frames for the changes of linkage.
Assigning the Link Controller
At frame 56 open the Motion panel.
In the Perspective viewport select handle.
Tip: Check the name at the top of the command panel to confirm your selection.
In the Assign Controller rollout, click Transform: Position/Rotation/Scale.
Click Assign Controller.
In the Assign Transform Controller dialog choose Link Control and click OK.
This assigns a Link Controller to the object the biped is going to pick up.
Zoom into the viewport to see the handle, the dummy, and the biped's hand.
In the Link Parameters rollout, click Add Link.
You'll link to two different objects. The biped hand will animate the briefcase. The handle will link to a dummy when you want the briefcase to remain stationary.
Select the blue dummy object near the briefcase handle.
The name "stay put dummy" appears in the Link Controller list.
Change the Start Time to 0.
Now you'll add Bip01 R Finger0 as the second link. You don't need to click Add Link again, as it is still active.
Select Bip01 R Finger0 (the large yellow box at the end of the biped's hand).
Bip01 R Finger0 appears in the Link Controller list, with a Start time of 56.
Select the dummy again and change its Start Time to 228.
Play the animation.
The biped picks up the briefcase, carries it, then sets it down.
We didn't bother rotating the fingers to create a grasp, since this biped has only one giant finger. For bipeds that do have more fingers you would link to the Bip01 Hand objects, rather than the finger objects. This would let you rotate the fingers together or individually to create the grasp without affecting the briefcase.
Tip: Do not make changes to the biped's hand after creating the links. If you need to correct the animation of the hand, delete the links, and then create them again after the animation is correct.
If the biped carries the object the entire time, you do not need to use the Link Controller. Instead, attach the object to the biped hand using Select and Link.
Lesson 4: Creating the Illusion of WeightCreating_the_Illusion_of_Weight