The animation stops because the motion path animation was shut off

 

The animation stops because the motion path animation was shut off when the blend attribute was
automatically created when you set the first keyframe. The blend attribute values are set to zero by
default. When the blend values are set to zero, the keyframe animation has full influence on the object,
and the path animation is shut off. When the blend values are set to one, the motion path has full
influence on the object and the keyframing is shut off. When the blend values are between zero and one,
the aircraft's motion is blended between the keyframe and motion path animation.
In the next steps, you keyframe the blending attributes so the blending begins at frame 30 and ends at
frame 70. This blends the two animation types together over a period of 40 frames.

To blend between the two animation types
1. Set the Timeslider to frame 30.
2. In the Channel Box, ensure the blend values are set as follows:
o BlendAddDoubleLinear: 0
o BlendMotionPath: 0
3. Select the BlendAddDoubleLinear1 and BlendMotionPath1 channels by click-dragging on their
names so they become highlighted.

4. Right-click on one of the names, and choose Key Selected from the drop down list that appears.
A key is set for the blend starting point for the aircraft. At frame 30 the two animation types will
begin to blend together.
5. Set the Timeslider to frame 70.
6. In the Channel Box, set the following:
o BlendAddDoubleLinear1: 1
o BlendMotionPath1: 1
7. Right-click on one of the names, and choose Key Selected from the drop down list that appears.

A key is set for the blend ending point for the aircraft. At frame 70 the motion path animation will
have full influence.
8. Click play on the Timeslider playback controls to play back the animation.

The two animation types are combined but the motion does not appear correct. The aircraft
rotation flips upward momentarily when it begins to travel along the motion path.



The interpolation type for the rotations during the blending is not set correctly.

Setting the pairBlend rotInterpolation setting to Quaternions changes how the rotations are interpolated
during the blend. In this example, Quaternions provides a better interpolation type when blending
between the keyframe and motion path animation. For more information see quaternion rotation in the
Maya Help.

To edit the rotation interpolation type for blending
1. In the Channel Box, click on the pairBlend1 channel.
2. Scroll the Channel Box so you can view the Attributes for pairBlend1.
3. Set the Rot_Interpolation setting to Quaternions by clicking on the Euler angles name with the left
mouse button.

4. Click on the pairBlend2 channel.
5. Click on the Euler angles name in the Rot_Interpolation attribute and choose Quaternions.
6. Click play on the Timeslider playback controls to play back the animation.
The animation plays back smoothly. Observe how the blending also takes into account the rotation
of the aircraft so it meets up with the motion path smoothly.


Using Playblast to playback an animation

Playblast allows you to preview an animation by calculating the separate frames and playing them back
in a multimedia player window based on the Playblast options. Playblast provides a more accurately timed
playback than using the Timeslider.

To playback the animation using Playblast
1. Select the path curve, and then select Display > Hide > Hide Selection to hide the curve while
you Playblast.
2. Select Window > Playblast.
Playblast calculates the frames for the animation and then plays them back in the player window.
You have completed this lesson.