GRAPH 1 - The red line stands for the Position of an object along the X axis.
If the POSITION of the object is at the location 10 in X at frame 0, and at the location 80 at frame 60 (60 frames is 2 seconds)
Where is object positioned at frame 30?
HINT: The RED straight diagonal line indicates that this is a linear motion. Halfway through the time, the object is halfway
through the motion. The GREEN horizontal line indicates that there is no motion, because the value for the green line never changes over time.
Answer: At frame 30 the object is positioned at location 45.
GRAPH 2 - The red line stands for the POSITION of an object along the X axis.
The objects position value doesn't change very much at the beginning of the animation,
then towards the end, the values change quickly. Does this graph represent an ease-in or an ease-out for the first key?
HINT: When we think about ease in/out, it's best to think, "Ease Out of a Keyframe, and Ease In to a Keyframe"
Answer: The graph represents an ease-out for the first key.
GRAPH 3 - The red line stands for the POSITION of an object along the X axis.
The objects position value change very quickly at the beginning of the animation,
then towards the end, the values change very little. Which keyframe (first or second) has the ease in applied to it?
HINT: When we think about ease in/out, it's best to think, "Ease Out of a Keyframe, and Ease In to a Keyframe"
Answer: The second keyframe has the ease in applied to it.
GRAPH 4 - The red line stands for the POSITION of an object along the X axis.
Describe the motion and direction of a ball using this graph for the X position.
HINT: Use frame numbers, and proper terminology such as linear, deceleration, acceleration.
Answer: The graph begins with the ball at a location of 10 on the left side it accelerates (ease out) towards the right, at frame 01:00f it begins to decelerate (ease in) until it reaches location 80.
GRAPH 5 - The red line stands for the POSITION of an object along the X axis.
Describe the motion and direction of a ball using this graph for the X position. Note the value of the first key.
Answer: The motion begins with the ball at location -10, it accelerates to the right (ease out) until frame 01:00f where it begins to decelerate until frame 02:00f where it reaches location 60.
GRAPH 6 - The red line stands for the POSITION of an object along the X axis.
Describe the motion
and direction of a ball using this graph for the X position.
NOTE: The handles have influence on the curve. The longer the handles, the more influence.
The shorter the handles, the less influence. The handle is always TANGENT to the curve at the keyframe.
Answer: The motion begins with the ball at location 70 it begins to decelerate to the left until frame 01:00f where it comes to a stop and turns around and accelerates towards the right until reaching its original position at location 70.
GRAPH 7 - The red line stands for the ROTATION of an object around the X axis.
Describe the direction of the rotation of the ball using this graph for the X rotation. Use frame #s to help in your answer.
NOTE: The handles are always on the 'outside' of the curve. That's because the quickest way between points is a straight line, the handles pull the curve away from the straight line.
Answer: The ball begins to rotate at frame 00:15f (front to back towards the inside of the screen, or away from us) -10 degrees.
GRAPH 8 - The red line stands for the SCALE of an object on the X axis. (The Y and Z scale is at a constant 100.)
Describe the scale of the ball using this graph for the X scale. Use frame #s to help in your answer.
NOTE: The handles can be broken to achieve an abrupt change of speed like in the graph above. To 'break' a handle, you can click on the PEN tool in the tool bar, and select the CONVERT VERTEX tool. (Looks like an upside down V )
Answer: The ball begins with a scale of -10% (ie backwards) constantly grows crosses the cero (practically invisible) horizontally to a scale of 80% at frame 1:00f. Immediately at frame 1:00f it decreases in size in an accelerating motion, to around a scale of 75% and then continues to decrease in size with a decelerating motion until it reaches a scale of 60% at frame 02:00.
GRAPH 9 - The red line stands for the POSITION of an object on the X axis. The green is the POSITION on the Y axis.
Describe the motion of the ball using this graph for both X and Y position. Use frame #s to help in your answer.
HINT: Negative values in Y translate the object upward. Positive values translate the object downward.
NOTE: Red is the color given to the X dimension of the transformation... Just like the red arrow indicates the X axis. Green is given to the Y dimension of the Transformation. Blue to the Z dimension.
Answer: The ball begins at a location of -10 and height of 50. It quickly travels to the right side of the frame to location 80 upwards at a height of about 27. At frame 1:00f it stops and begins to move slowly to the left still going in the right directions coordinates (80,0).
GRAPH 10 - The red line stands for the POSITION of an object on the X axis. The green stands for the POSITION on the Y axis.
Describe the motion of the ball using this graph for the X and Y. Use terminology and frame #s to help in your answer.
NOTE: You can modify the handles on more than on keyframe at the same time. So be careful when you are selecting keys that you don't mistakenly adjust handles on keyframes that you didn't intend.
Answer: the ball begins at an x location of -10 and height of 50, it quickly moves to the right to location 80 and begins to accelerate downwards to frame 00:15f. Here, it turns around and accelerates to the left, but continues it's path upwards, until around frame 01:07f where it turns around once more and accelerates to the right again at location 40, while in the y axis its decelerating at a height of -10 meaning its going up.
At fram 01:15f it changes direction on the y-axis at y= -15 and begins to accelerate upwards, whilst on the x-axis its accelerating at x=40, until frame 02:00f its a location of 60 height of 0 (60,0) meaning on the top right of the frame.
GRAPH 11 - The blue line stands for the ROTATION of an object around the Z axis. The object is the pendulum on a clock.
The anchor point is at the top of the pendulum so it swings back and forth like you would normally see.
Describe the motion and direction of the pendulum using this graph for the Z rotation.
NOTE: To have smooth transitions across keyframes, make sure your Handles are perfectly horizontal. (like above) You can hold the Shift key down to keep the handles horizontal. The last key should have had a horizontal handle to ease into the final position.
Answer: It begins at a position of 90, and moves counter-clockwise -60 degrees, then accelerates in the other direction (clockwise) to reach 40 degrees, at around fram 01:04f where it comes to a stop, and changes direction, turning counter clockwise to reach -20 degrees. Comes to a stop, and accelerates in the other direction, clockwise to reach 0 degrees (ie. the center).
GRAPH 12
Describe the motion and direction of an object if this graph was for the POSITION of an object.
NOTE: Color determines the dimension!
Answer: The ball begins at a location of -20, height outside of the frame at -10 with a dimension of 30. At the second keyframe 00:15f, the ball has traveled downward to the right to location (5,15) and moving going away from you until value -20.
Third Keyframe: 01:05f, the ball has rotated clockwise to 10 degrees, and traveled to the right downwards to (44,40), its decelerating upwards to come to a stop at y=43.
Fourth Keyframe: the ball has changed direction in y axis, it's now traveling upwards at a value of around y= 41, still to the right at a value of x=75.
Fifth Keyframe: The ball has rotated clockwise from the previous keyframe to reach the center at 0 degrees. With a deceleration on the y-axis going upwards, on the right side at x=90.
GRAPH 13
This graph is impossible to create in After Effects, why?
NOTE: Use AE and try it out.
Answer: Because there are two numerical values at the same frame. Frame 01:02f has a value of both 20 and about 45, which makes it imposible to create.
GRAPH 14
This graph is a good representation of 'overshooting' a keyframe? How does this graph represent the 'overshoot'?
NOTE: If you don't know what 'overshooting' a keyframe is check out some traditional animation books.
Answer: it quickly travels to the right, creating a somewhat upside-down parabola, and at frame 01:75f it quickly changes direction to the left a bit. Past the vertex or maximum point.
GRAPH 15
This graph represents the Y position of a bouncing ball. Will this make for a good bounce? Explain why or why not.
NOTE: The name for this type of curve is call BEZIER. Pronounced: bez ee ay (After Frenchman Pierre Bézier from Regie Renault) A collection of formulae for describing curved lines (Bezier Curves) and surfaces (Bezier Surfaces) , first used in 1972 to model automobile surfaces. Curves and surfaces are defined by a set of "control points" which can be moved interactively making Bezier curves and surfaces convenient for interactive graphic design. ["Principles of interactive computer graphics", William M. Newman, Graw-Hill]
Answer: No, because when it reaches the vertex of the parabola and begins to go back down again, the acceleration, before and after y=-10 must be the same in order for the bounce to work. Also, the bounce would need to occur at frame 01:15f for it to be consistent.
GRAPH 16
Would this graph represent a good animation for the Y position of a bouncing ball. Explain why or why not.
NOTE: When you have the layer selected, and you are in the Motion Graph editor, you can see the motion path (line of connected dots)in the composition window update instantly.
Answer: No, it won't make for a good bounce, because the angle coming up must be the same as the angle going down, which is not the case in this graph and the handles must be placed horizontal to the curve. Also the curve must be upside down for the ball to bounce realistically.
GRAPH 17
If you had to 'fix' this graph so it would be a good bounce in Y, what would be three things you might do to fix it?
Hint : Use the term Parabola in your answer.
Answer:
1)I would place the third keyframe at y=70, for the ball to bounce in the same y position every time.
2) move the third keyframe to frame 01:00f, to create a uniform parabola.
3) Elongate the right handle of the second keyframe and make it the same length as the left handle.
GRAPH 18
You've animated a ball bounce by hand, so you remember all the challenges of creating nice arcs, squash and stretch, good spacing.
And knowing a bit about how to read graphs, describe what you think the three curves represent. What do you think the green curve and the red, and the blue curve represent.
Answer:
Green Curve: the displacement of the ball in the y-axis, the maximum height it reaches y=20, and when it hits the ground y=90.
Red Curve: The displacement of the ball in the x-axis, the ball begins at x=100, and is then displaced to the left, ending at x=30.
Blue Curve: The rotation of the ball throughout the animation from frame 0 to frame 02:00f.
Question 19
Why would you NOT use the keyframe assistant > Easy Ease to create all your animation?
Answer:
Because the keyframe assistant gives you the standard easy ease value for animation. It doesn't necessarily give a realistic representation of acceleration, or deceleration because it changes from case to case. For example, a heavy ball will have a different acceleration than a light ball in a ball bounce animation, and a different value of interpolation. This is where the skill of the animator comes in in determining the best value for this to create the most realistic representation of a ball bounce.
Question 20
Why is it so important to Separate Dimensions on a transformation when you are animating?
Answer:
Because the x-axis and y-axis dont hold the same values throughout the entire animation. Hence, the have to be approached separately, and unless they are separated from the beginning you wont be able to manipulate one without manipulating the other at the same time.