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PowerPoint Presentation - Computer Graphics Homepage


									Other Animation Skills

      Graphics Lab.
       Korea Univ.
     Change the View Port
• Click right on “Perspective” in the low
  er right viewport.
• Select “Configure” and “Layout”.
• Choose the fourth layout from the top
• Open “Track View” and adjust the
  new window to expose most of the
   lower viewport.
               Create a Box
• Use the “Create” button on the Command Menu
  to make a box of L=50, W=100, H=50.
• Click left then right on “Select and Move” on the
  main toolbar, to bring up the “Move Transform
  Type In” Dialog box.
• Enter zeros for the absolute world coordinates
  of x, y and z in the dialog box so that the box
  will be centered on the origin.
• Open the “Objects”, “BOX01” and “Transform”
  nodes in track view.
   Make Controllers Visible
• Click left on “Filters” on the left side
  of the track view toolbar.
• Check the box labeled “Controller
• Now Max shows you the controllers
  for position, rotation and scale in
  track view.
The controller for each track is
indicated next to the track name.
Creation of Keys in Track View
• Click on “Edit Keys” and “Add Keys”.

• Put keys at frames 0, 25, 50 and 100.

• As you place each key, you may adjust
  the frame number by typing in the slot
  at the bottom of the track view window
Edit Keys         Create Keys

            Frame Type In
        Editing a Key Value
• Click right on the
  key at frame 50.

• Enter a value of 100 for
  X in the dialog

• Put the dialog box
          Function Curves
• Click on “Function Curves” on the top of tr
  ack view.
• Click on “Zoom Value Extents” at the lower
  right of track view, to center the curves.
• Red is X, Green is Y and Blue is Z.
• Notice that the X curve rises to meet the ke
  y value at frame 50.
• Notice that the X curve undershoots at first
  and overshoots later on.

        What went wrong?
• Max is using a cubic Bezier spline to
  interpolate our four position keys.
• Max assumes we want the curve to be
  smooth, i.e., continuous first derivative.
• The box’s motion in the X direction cannot
  start and stop instantly.
• Click on “Play Animation” at the lower right
  of the Max window to see the effect.
        Fixing the Problem
• Click right on the key at frame 25 to open
  a dialog box.
• Click on the “In” button and select the last
• Adjust the tangent handle to flatten out the
• Use the dialog box left arrow to go back to
  the key at frame 0, and do the same thing
  using the “Out” button.
• Now play the animation.
The curve has been flattened out
from frames 0 to 25 by adjusting
the tangent handles at those two
 Unlocking Tangent Handles
• Select the key at frame 25 and open the
  key’s dialog box.
• Click left on “Advanced” set the X derivative
  values at this key to zero, if they are not
  quite exactly zero.
• Try unlocking the “In” and “Out” tangent
  handles for the X curve.
• Move the “Out” handle and observe that the
  “In” handle remains fixed.
• Use the “Undo” button on the top left of the
  main toolbar to relock the tangent handles
  and flatten the curve.
“In” Derivative   Tangent Handle Locks
    Type In
                                 “Out” Derivative
                                     Type In
        Making the Box Rest
• Create a new key at frame 75 and use the key
  dialog box to set its X value to 100, the same as the
  key at frame 50.
• Notice that the box does not remain at rest between
  frames 50 and 75.
• Use the “In” button on the key at frame 75
  to select the “Piecewise Constant” option.
• Notice that the box now stays fixed from frame 50
  to frame 75.
• Notice that Max adjusted the slope into frame 50
  and out of frame 75 to make the motion smooth.
• Try changing this using tangent handles, and them
  use “Undo” to make the motion smooth again.
The “Piecewise Constant”
option on the “In” button has
made the curve flat from
frames 50 to 75, and smooth
at these two points.
     Ease In and Ease Out
• Play the animation.
• Notice that the box stops suddenly at the
• This occurs because the slope of the X
  function curve is not zero at frame 100.
• Open the key dialog box for the key at frame
  100, and choose the “Ease In”
  (second to last) option on the “In” button.
• This forces the slope to be zero at frame
The “Ease In” option on the
“In” button has made the curve
flatten out at frame 100.
       The “Animate” Button
• Move the “Time Slider” bar to frame 35.
• Click right on the big “Animate” button.
• Click left on “Select and Move” on the Main
• Restrict to move along the X axis.
• Move the box a little to the right. Notice that a new
  key was created at frame 35.
• Move the Time Slider to frame 100.
• Move the box a little to the right once again.
  Notice that the old key at frame 100 has moved.
• Turn off the Animate button. Move the box once
  again. Notice that the whole graph moves.
• Undo (only) the last move operation.
Track view after adding a key at frame 35 and
changing the key at frame 100.
  Active Time Segment and
Out of Range Function Curves
• Click right on the “Play Animation” button to open
  the “Time Configuration” dialog box.
• Set the length of the “Active Time Segment” to 400.
• Play the animation and notice that the box does
  nothing after frame 100.
• Click on “Parameter Curve Out of Range Types” on
  the Track View menu bar.
• Select “Relative Repeat” (out of range above).
• Play the animation and notice that the box repeats
  its motion, offset a bit to the right on each cycle.
 Click left on “Zoom Horizontal Extents” to see the
function curves over the entire Active Time Segment.
        TCB Position Controller
• Reinitialize Max using the “File” and “Reset”
  menu items.
• Select the “Top” viewport in the upper left corner
• Use the “Min/Max Toggle” button at the
  lower right corner of the screen to expand the
  size of the Top viewport.
• Use the “Time Configuration” button to set the
  active time segment to (0…120).
         TCB Position Controller
• Create a sphere at (x,y)=(-100,100), using the
  “Move Transform Type In” dialog box.
• Open track view and select the sphere’s position track.
• Make controllers visible using the “Filters” button.
• Use the “Assign Controllers” button to assign the
  “TCB Position” controller to the sphere’s position track.
• Use the “Animate” button to create position keys at 0, 20,
  40, 60, 80, 100, 120, at positions
  (-100,100), (100,100), (100,-100), (-100,-100),
  (-100,100), (100,100), (100,-100).
• Use the “Time Configuration” button to set the active time
  segment to (20…100).
Tension, Continuity and Bias
• Tension determines whether the sphere
  makes a sharp turn (at slow speed) or a
  wide turn (at high speed).
• Continuity determines whether the tangent
  to the sphere’s path is continuous or
  makes sudden jumps
  (clockwise or counter clockwise).
• Bias determines whether the sphere
  swings outside the square before of after
  the turn.
Tension, Continuity and Bias
• Select any sphere position key and click
  right to bring up the position key dialog box.
• Use the dialog box to systematically vary
  tension (T), continuity (C) and bias (B) of all
  seven keys in unison.
• Play the animation.
• Select the sphere and click on the “Motion”
  tab of the Command Panel to see the
• Use the “Snapshot” facility under “Tools” on
  the Max Main Menu.
T = 25   C = 25   B = 25
T = 25   C = 25   B = 25
T = 25   C = 25   B = 25
T = 25   C = 25   B=5
T = 25   C = 25   B=5
T = 25   C = 25   B=5
T = 25   C = 25   B = 45
T = 25   C = 25   B = 45
T = 25   C = 25   B = 45
T=5   C = 25   B = 25
T=5   C = 25   B = 25
T=5   C = 25   B = 25
T = 45   C = 25   B = 25
T = 45   C = 25   B = 25
T = 45   C = 25   B = 25
T = 25   C=5   B = 25
T = 25   C=5   B = 25
T = 25   C=5   B = 25
T = 25   C = 45   B = 25
T = 25   C = 45   B = 25
T = 25   C = 45   B = 25
        Spline Conversion
• Reset Max and configure viewports to
  show Front and Top views
  (as done previously.)
• Open track view and place it above the
  Top viewport.
• Use the “Filters” menu item in track view to
  show “Controller Types”.
• Create a sphere in the lower viewport and
  put it anywhere.
• Select the sphere’s position track and use
  the “Assign Controllers” to assign the track
  a “Position X, Y, Z” controller.
 Spline Conversion (Cont’d)
• Use the “Create” tab and “Shape” button on
  the Command Panel to make a horizontal
  line in the bottom part of the lower viewport.
• Use the “Modify” tab and “SubObject”
  button on the Command Panel, along with
  the “Move Transform Type In” dialog box to
  make the two end vertices of the line have
  the same Z value.
• Leave SubObject model and select the
         Converting the Line into
              a Trajectory
• Click left on the “Motion” tab on the Command Panel and
  press the “Trajectories” button.
• Click left on the “Convert From” button and then click left
  on the line object in the lower viewport.
• You have converted the line into a trajectory for the sphere.
• Go to track view, select the X position track, and turn on
  the “Function Curves” button.
• Notice that X is a linear function of time.
• Notice that the tick marks on the trajectory are equally
• Play the animation. The sphere should move at a uniform
  Edit Keys on the Trajectory
• In track view, select the sphere’s “Position” track.
• Use the “Assign Controller” button to assign a
  “Bezier Position” controller to the track.
• Notice that keys have appeared on the trajectory.
• Press the “SubObject” button on the Motion Panel
  to get access to the trajectory keys.
• Click “Select and Move” and “Restrict to X” on the
  Main Toolbar.
• Select and move trajectory keys leftward in order to
  create an acceleration.
• Play the animation and observe the acceleration.
           Path Animation
• Reset Max and set up the same viewport
  configuration as before.
• Create a small cone object in the upper
  (Top) viewport.
• Draw an ellipse object in the lower (front)
• Open track view, show controllers, and
  assign a “Path” controller to the position
  track of the cone.
• Expand the position track to see three new
  tracks beneath.
          Path Animation
• Select the cone and go to the Motion
  tab on the Command Panel.
• Press the “Parameters” button and
  the “Pick Path” button. Then click left
  on the ellipse.
• Move the Time Slider Bar to see that
  that cone moves along the ellipse.
           Editing the Path
• Select the ellipse.
• Go to the Modify tab on the Command Panel.
• Click right on the Edit Stack icon and select
  “Convert to Editable Spline”.
• Press the SubObject button.
• Select and move ellipse vertices.
• Observe that that the cone follows the
  modified ellipse.
• Use the Undo button to restore the ellipse to
  its original shape.
  Making the Cone Rotate
  Around the Elliptical Path
• Select the cone and go to the Motion
  tab on the Command Panel.
• Check “Follow”, “Allow Upside Down”
  , and “Z” axis on “Path Options”.
• Observe that the cone rotates as it
  moves around the ellipse.
• The major axis of the cone is always
  tangent to the ellipse.
Adjusting the Rate of Motion
        Along a Path
• Play the animation and notice that the cone slows
  down near the apexes of the ellipse.
• Check the “Constant Velocity” box plan the
  animation again. Now the cone moves at a
  constant speed.
• Go to Track View and edit the “Percent” track
  under the cone’s Position track.
• Add a key at frame 50, and adjust the tangent
  handles at frames 0, 50 and 100 so that the
  cone will slow down at the apexes of the ellipse.

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