Animation Lesson 4: Open the second scene for the lesson
In this second half of this lesson, you work with a second scene file that contains motion capture data
applied to a skeleton.
Motion capture data is produced by capturing the movement of a real human or animal and digitizing it so
it can be applied to a 3D animation character. Motion capture data contains keyframe animation. Motion
capture data is useful because it can capture the subtle nuances of motion and gesture that make a
character's actions appear life-like. Motion capture data can substantially reduce the work related to
posing and keyframing your characters.
1. Open the scene named Trax_Lesson2.mb.
You can open the scene named Trax_Lesson2.mb from the Maya Documentation, Lessons, and
Extras CD or from the drive where you copied the Getting Started files.
The skeleton appears in the Maya scene in the standard da Vinci pose. In this pose, the
character stands straight with its arms extended out to either side. This pose is useful when you
need to skin a character, retarget animation from one skeleton to another, or set a rest pose for
the skeleton.
In this half of the lesson you learn how to use the Trax Editor to work with motion capture data
by extending and redirecting the motion for a character.
Note
If you are beginning the lesson from this point, you must first set your panel layouts and display
settings for the Trax Editor and Outliner. Refer to To set a panel layout for use with the Trax Editor
and To set the Outliner to display clips.
If your skeleton doesn't appear as shown, you will need to increase the size of the skeleton's
joints.
To resize the joints on the skeleton
1. From the main menu, select Display > Joint Size > Custom.
The Joint Display Scale window appears.
2. Set the Joint Display Scale to 10.
3. Close the Joint Display Scale window.
To preview the motion capture animation
1. Click play on the Time Slider playback controls to play back the animation.
The skeleton is repositioned and then walks from left to right, stops, and then sits.
2. Press stop on the Time Slider's playback control.
Creating clips from motion capture data
When creating a clip from motion capture, it is a good practice to begin by creating a source clip from
the entire motion sequence that excludes the Da Vinci pose. You can create the clip and save it to the
Visor or Outliner directly without loading it onto a track. You can later revert back to the source clip and
load it into a track if necessary.
To create a source clip of the motion capture data
1. In the Time Slider, set the Playback Start Time to 1.
2. Press the Go to Start of playback range button to return to frame 1 in the Time Slider.
The skeleton is repositioned at frame 1 where the walking motion begins.
3. In the persp view, select the skeleton by click-dragging a bounding box around the skeleton.
The skeleton is highlighted. When the skeleton is selected, many red ticks appear in the Time
Slider. The red ticks represent keyframes from the motion capture data.
4. In the Trax Editor menu, select Create > Clip > .
The Create Clip Options window appears.
5. In the Create Clip Options window, click Edit > Reset Settings to set the tool to its default
settings, and then set the following:
o Type WalkSit in the Name field.
o Keys - Leave Keys in Timeline: On
o Put Clip in Visor Only: On
o Click Create Clip.
Extending the length of motion capture data
You often need more animation of a motion sequence than is provided in the motion capture data. For
example, you may need to have a walk cycle that is substantially longer than what was provided in the
original file. You can use the Trax Editor to edit the motion capture data and create clips that can be
cycled to make longer animation sequences. When you cycle a clip, the clip is extended in length with
duplicate animation from the original clip over a defined interval of time.
If you want to cycle a clip, you must first determine areas within the animation sequence where the clip
repeats seamlessly. For example, if you want to create a walk cycle from the motion capture data, you
need to determine the time (frame) where the right foot is planted on the ground, and then move forward
in the Time Slider, frame by frame, until you find the next frame where the right foot is planted on the
ground in exactly the same (or very similar) manner, and then create a clip. The resulting clip will contain
two steps of the walking motion. The clip can then be cycled to produce a motion that repeats. How
seamlessly it cycles depends on the original motion capture data.
In the steps that follow you create a walk cycle from the motion capture data by:
Creating a clip from the walking portion of the motion capture sequence that can be repeated.
Cycle the clip to create a longer walk sequence.
To create a clip that can be cycled
1. In the Time Slider, drag the current time indicator to frame 6.
The skeleton updates in the scene to a walking pose where the right foot is planted on the
ground.
2. Drag the current time indicator forward in the Time Slider until you reach frame 45.
At frame 45, the skeleton is posed in a similar manner as it appeared at frame 6. If you use this
range of frames (6 to 45), you can create a clip that can be cycled.
3. In the persp view ensure the skeleton is selected.
4. In the Trax Editor menu, select Create > Clip > .
The Create Clip Options window appears.
5. In the Create Clip Options window, click Edit > Reset Settings to set the tool to its default
settings, and then set the following:
o Type WalkCycle in the Name field.
o Put Clip in Trax Editor and Visor: On
o Time Range: Start/End
o Start Time: 6
o End Time: 45
o Click Create Clip
Two clips appear in the Outliner named WalkCycle and WalkCycleSource.
6. In the Trax Editor, with the skeleton selected, click the Load Selected Characters icon.
The source clip appears in the Outliner named as WalkSitSource. (If you use the Visor, the clip
appears under the Character Clips tab.)
The clip named WalkCycle appears in a new track. Loading the Character displays any tracks
associated with the character; in this case the WalkCycle clip.
7. In the Time Slider, set the current time indicator to frame 1.
8. Click play on the Time Slider playback controls to play back the clip.
The skeleton takes two steps and stops.
9. Press stop on the playback controls to stop the playback and reset the current time indicator to
frame 1.
10.In the Trax Editor, drag the clip to the left in its track until the Frame In number reads 1.
This sets the clip to begin at frame 1 in the Time Slider.
In the steps that follow, you cycle the clip to extend the animation so the skeleton repeats the two step
motion and travels farther in the scene.
To cycle the motion for the walk clip
1. In the Trax Editor, shift-drag the lower right corner of the Walk clip to the right until a C2.0
number appears in the new region of the clip.
When you shift-drag over the Frame Out area, the mouse cursor changes to a circular pointing
arrow to indicate you are cycling the clip.
2. Double-click on the cycled clip in the C2 region.
The region is highlighted to indicate you can edit the values in the region. The number will likely
not be exactly 2.0. This means that the cycle will not repeat exactly twice.
3. Type 2.0 to modify the clip so it cycles exactly twice.
4. With the clip selected in the Trax Editor, open the Channel Box and ensure that the WalkCycle
clip's Offset channel is set to Relative.
Setting the Offset attribute for the clip to Relative ensures that each cycle begins at the position
where the last sequence left off. This ensures that the skeleton doesn't jump back to its start
point after each cycle.
5. Click play on the Time Slider playback controls to play back the clip.
The skeleton takes six steps and then stops.
When the clip is cycled twice, the two-step walking motion occurs three times in total.
6. Press stop on the playback controls to stop the playback and reset the current time indicator to
frame 1.
In this second half of this lesson, you work with a second scene file that contains motion capture data
applied to a skeleton.
Motion capture data is produced by capturing the movement of a real human or animal and digitizing it so
it can be applied to a 3D animation character. Motion capture data contains keyframe animation. Motion
capture data is useful because it can capture the subtle nuances of motion and gesture that make a
character's actions appear life-like. Motion capture data can substantially reduce the work related to
posing and keyframing your characters.
1. Open the scene named Trax_Lesson2.mb.
You can open the scene named Trax_Lesson2.mb from the Maya Documentation, Lessons, and
Extras CD or from the drive where you copied the Getting Started files.
The skeleton appears in the Maya scene in the standard da Vinci pose. In this pose, the
character stands straight with its arms extended out to either side. This pose is useful when you
need to skin a character, retarget animation from one skeleton to another, or set a rest pose for
the skeleton.
In this half of the lesson you learn how to use the Trax Editor to work with motion capture data
by extending and redirecting the motion for a character.
Note
If you are beginning the lesson from this point, you must first set your panel layouts and display
settings for the Trax Editor and Outliner. Refer to To set a panel layout for use with the Trax Editor
and To set the Outliner to display clips.
If your skeleton doesn't appear as shown, you will need to increase the size of the skeleton's
joints.
To resize the joints on the skeleton
1. From the main menu, select Display > Joint Size > Custom.
The Joint Display Scale window appears.
2. Set the Joint Display Scale to 10.
3. Close the Joint Display Scale window.
To preview the motion capture animation
1. Click play on the Time Slider playback controls to play back the animation.
The skeleton is repositioned and then walks from left to right, stops, and then sits.
2. Press stop on the Time Slider's playback control.
Creating clips from motion capture data
When creating a clip from motion capture, it is a good practice to begin by creating a source clip from
the entire motion sequence that excludes the Da Vinci pose. You can create the clip and save it to the
Visor or Outliner directly without loading it onto a track. You can later revert back to the source clip and
load it into a track if necessary.
To create a source clip of the motion capture data
1. In the Time Slider, set the Playback Start Time to 1.
2. Press the Go to Start of playback range button to return to frame 1 in the Time Slider.
The skeleton is repositioned at frame 1 where the walking motion begins.
3. In the persp view, select the skeleton by click-dragging a bounding box around the skeleton.
The skeleton is highlighted. When the skeleton is selected, many red ticks appear in the Time
Slider. The red ticks represent keyframes from the motion capture data.
4. In the Trax Editor menu, select Create > Clip > .
The Create Clip Options window appears.
5. In the Create Clip Options window, click Edit > Reset Settings to set the tool to its default
settings, and then set the following:
o Type WalkSit in the Name field.
o Keys - Leave Keys in Timeline: On
o Put Clip in Visor Only: On
o Click Create Clip.
Extending the length of motion capture data
You often need more animation of a motion sequence than is provided in the motion capture data. For
example, you may need to have a walk cycle that is substantially longer than what was provided in the
original file. You can use the Trax Editor to edit the motion capture data and create clips that can be
cycled to make longer animation sequences. When you cycle a clip, the clip is extended in length with
duplicate animation from the original clip over a defined interval of time.
If you want to cycle a clip, you must first determine areas within the animation sequence where the clip
repeats seamlessly. For example, if you want to create a walk cycle from the motion capture data, you
need to determine the time (frame) where the right foot is planted on the ground, and then move forward
in the Time Slider, frame by frame, until you find the next frame where the right foot is planted on the
ground in exactly the same (or very similar) manner, and then create a clip. The resulting clip will contain
two steps of the walking motion. The clip can then be cycled to produce a motion that repeats. How
seamlessly it cycles depends on the original motion capture data.
In the steps that follow you create a walk cycle from the motion capture data by:
Creating a clip from the walking portion of the motion capture sequence that can be repeated.
Cycle the clip to create a longer walk sequence.
To create a clip that can be cycled
1. In the Time Slider, drag the current time indicator to frame 6.
The skeleton updates in the scene to a walking pose where the right foot is planted on the
ground.
2. Drag the current time indicator forward in the Time Slider until you reach frame 45.
At frame 45, the skeleton is posed in a similar manner as it appeared at frame 6. If you use this
range of frames (6 to 45), you can create a clip that can be cycled.
3. In the persp view ensure the skeleton is selected.
4. In the Trax Editor menu, select Create > Clip > .
The Create Clip Options window appears.
5. In the Create Clip Options window, click Edit > Reset Settings to set the tool to its default
settings, and then set the following:
o Type WalkCycle in the Name field.
o Put Clip in Trax Editor and Visor: On
o Time Range: Start/End
o Start Time: 6
o End Time: 45
o Click Create Clip
Two clips appear in the Outliner named WalkCycle and WalkCycleSource.
6. In the Trax Editor, with the skeleton selected, click the Load Selected Characters icon.
The source clip appears in the Outliner named as WalkSitSource. (If you use the Visor, the clip
appears under the Character Clips tab.)
The clip named WalkCycle appears in a new track. Loading the Character displays any tracks
associated with the character; in this case the WalkCycle clip.
7. In the Time Slider, set the current time indicator to frame 1.
8. Click play on the Time Slider playback controls to play back the clip.
The skeleton takes two steps and stops.
9. Press stop on the playback controls to stop the playback and reset the current time indicator to
frame 1.
10.In the Trax Editor, drag the clip to the left in its track until the Frame In number reads 1.
This sets the clip to begin at frame 1 in the Time Slider.
In the steps that follow, you cycle the clip to extend the animation so the skeleton repeats the two step
motion and travels farther in the scene.
To cycle the motion for the walk clip
1. In the Trax Editor, shift-drag the lower right corner of the Walk clip to the right until a C2.0
number appears in the new region of the clip.
When you shift-drag over the Frame Out area, the mouse cursor changes to a circular pointing
arrow to indicate you are cycling the clip.
2. Double-click on the cycled clip in the C2 region.
The region is highlighted to indicate you can edit the values in the region. The number will likely
not be exactly 2.0. This means that the cycle will not repeat exactly twice.
3. Type 2.0 to modify the clip so it cycles exactly twice.
4. With the clip selected in the Trax Editor, open the Channel Box and ensure that the WalkCycle
clip's Offset channel is set to Relative.
Setting the Offset attribute for the clip to Relative ensures that each cycle begins at the position
where the last sequence left off. This ensures that the skeleton doesn't jump back to its start
point after each cycle.
5. Click play on the Time Slider playback controls to play back the clip.
The skeleton takes six steps and then stops.
When the clip is cycled twice, the two-step walking motion occurs three times in total.
6. Press stop on the playback controls to stop the playback and reset the current time indicator to
frame 1.
No comments:
Post a Comment