In MotionBuilder, you can animate characters by setting keyframes manually or by using motion-capture data. This lesson shows you how to do both.

Check the frame rate:

• On the Transport Controls panel, check the frame rate (this control is to the right of the playback buttons). If it is not set to 30 fps, use the drop-down list to make sure that 30 fps (frames per second) is the frame rate for this animation.

  

  In MotionBuilder 2011, the default frame rate is 24 fps. In earlier versions of MotionBuilder, the default frame rate was 30 fps.

  TipThe frame rate is customizable in both MotionBuilder and 3ds Max. For this tutorial, we use 30 fps to match the 3ds Max default. For your own projects, the frame rate you choose should depend on the format of your target medium: If you are producing an animation for North American television or Gameplay (NTSC format), then use 30 fps for both applications; if you are producing an animation for a motion picture on film, then use 24 fps for both applications, and so on.

Load Pepe with characterization:

1. In MotionBuilder, from the main menu, choose File New.
2. In the Asset Browser Export folder, click to highlight pepe_biped_characterized.fbx.

   

   This file contains the Pepe character you worked on in the last few lessons. To speed things up, he has already been characterized and saved in MotionBuilder, so he is ready to receive animation.

3. Drag pepe_biped_characterized.fbx to the Viewer.
4. On the pop-up menu that appears, choose FBX Open <All Takes>.

   

   MotionBuilder has the ability to store multiple animation “takes” or sequences within the same project, and this option would open all of them if they existed. Alternatively, you could choose <No Animation> or Take 001.

5. With the cursor in the Viewer, press A to zoom in to the Pepe character.
6. Press Ctrl+Shift and drag to orbit until the Pepe’s right side is in view.

   

   Pepe is ready to accept keyframe animation using control-rig input from the Character Controls window. But in this case, you will retarget animation to Pepe from one of the motion-capture files that ship with MotionBuilder.

Animate the Pepe character using motion-capture data

1. From the Asset Browser Export folder, choose iceslip and drag it to the Viewer.

   

2. A pop-up menu appears. Choose FBX Merge IceSlip.

   

3. Zoom out until the yellow skeleton that represents the motion-capture animation is visible.

   

   Pepe with skeleton containing motion-capture information

   NoteIf you do not see the yellow skeleton, place your cursor in the Viewer and press Ctrl+A to exit Models Only mode.
4. On the Transport Controls, click (Play) to view the animation.

   

   You will now assign this movement to the Pepe character. In MotionBuilder, this task is easy to accomplish.

Apply the animation to the Pepe character:

1. On the Character Controls window Character Controls pane, make sure PEPE is displayed in the character list.

   

2. Choose Edit Input Skeleton2, which is the yellow skeleton containing the motion-capture animation.

   

3. Scrub the animation either by dragging the animation slider bar, or by holding down the J key and dragging left or right in the viewport.

   The skeleton’s animation now drives the Pepe character.

Identify a problem area:

The skeleton is a good deal larger than Pepe, and when scales are mismatched in this way, you can expect that some motion doesn’t translate correctly.

1. Press Ctrl+A until only Pepe is visible.
2. Drag the timeline indicator (equivalent to the 3ds Max time slider) to frame 92. You can also use the Play Controls to find the right frame.
3. Zoom in on the Pepe character.

   If you look carefully, you will see how one of Pepe’s hands passes into his face. You might need to orbit the Viewer and scrub the animation a few times to see the problem.

   

   Unwanted hand movement inherited from motion capture

   This behavior occurred because the animation driving Pepe’s bone movement is based on the skeleton, which has a very different physiology. (Pepe’s head, hands, and feet, for example, are much larger than the skeleton’s, while his shoulders are much narrower.)

   In the next procedure, you will correct Pepe’s hand movement.

Correct the hand-in-the-face problem:

1. On the Character Representation, click the right hand effector, then press T and try to move Pepe’s hand in the viewport.

   Nothing happens because Pepe’s animation is controlled by the skeleton, not the control rig. Before you can go any farther, you need to bake the skeleton animation onto the Pepe character’s control rig.

2. On the Character Control window Character Controls pane Edit menu, choose Plot Character.

   

3. On the Character dialog, click Control Rig.

   

   On the second Character dialog, leave the default values unchanged, and click Plot.

   

   Now you can edit the Pepe character using his control rig.

   NoteThe Plot command creates a key at every frame at the base layer of the animation track, which makes edits difficult. Because of this, you will edit the keyframing on a different layer.
4. On the Key Controls window, click the Base Layer list and choose Layer 1.

   

   The keyframes are hidden on the timeline, clearing your workspace.

5. Go to frame 80, which is the start of the problem hand movement. On the Character Representation, click the right wrist effector, then on the Key Controls panel, click Key.

   

   TipYou can also create a key by placing your cursor anywhere in the Viewer and pressing K.
6. Go to frame 105, the end of the problem hand movement, and click Key again.

   All character movement before the first key and after the second will remain unchanged. Only the character movement between frames 80 to 105 will be modified.

7. Go to frame 94, the midpoint between the two new keyframes you set.
8. Make sure the right hand effector is still active. In the Viewer, press T, move the hand away from Pepe’s face on its X and Z axes, and create another key.

   

   Left hand repositioned away from character’s face

9. Hold down J, then drag back and forth to see how the hand reacts to the keys you just created.

   Pepe’s hand no longer intersects with his face while he is falling.

Correct the hand position after Pepe has fallen:

1. Advance to the last frame of the animation and adjust the Viewer until you can see the right side of Pepe’s body.

   

   Right hand too close to the character’s head

2. Move the hand away from the body and create a key.
3. Press R and use the rotate gizmo to modify the hand’s position until it rests flat on the ground, then create another key.

   

   Rotate gizmo used to reposition right hand

4. Go to frame 114 and position the right hand farther away from the head and create another key.
5. Play back the animation to see the result.

   When you are satisfied with the animation, proceed to the next lesson. There, you will save your work and prepare it for import back to 3ds Max.