Now that you’ve adjusted time settings and the biped itself, you’re ready to block the basic walk cycle, working from pose to pose. This involves positioning the legs in space and time, giving the walk its overall tempo. You will begin with the quadruped’s forelegs.

Set up the scene:

• On the Quick Access toolbar, click (Open File), navigate to the \character_animation\quadruped folder, and open quadruped_walk_2.max.

  This scene is the same as the one you just saved, but a set of reference poses has been set up on planes in the background.

Configure character studio:

1. Use (Orbit) to change the viewport so you can see all four of the quadruped’s feet.

   

2. Use Ctrl+click to select both hind feet and both hands (forefeet).
3. On the Motion panel Quaternion/Euler rollout, choose Euler.

   Euler keys have tangent controls, which can be useful for this walk cycle exercise.

4. On the 3ds Max status bar, to the right of the Set Key button, choose (Linear) as the Default In/Out Tangent type.

   Sometimes blocking the animation is easier without extra interpolation (which you can add later).

5. Also on the Motion panel, open the Key Info rollout and expand its IK group (click the plus-sign icon to the left of the IK label).

   

6. Finally, open the Copy/Paste rollout as well.
   TipTo see both the expanded Key Info rollout and the Copy/Paste rollout, it might help to make the Command panel two columns wide: drag the left border of the Command panel to the left to make the Command panel wider.
7. Press Shift+Z to undo the viewport change and return to the Left view.

   (Depending on how you adjusted the viewport, you might have to click Shift+Z more than once to return to the Left view.)

Begin posing the front legs:

1. Make sure you are at frame 1, then turn on (Auto Key).
2. Use both (Move) and (Rotate) to position the arms (forelegs) and hands (forefeet) to match the reference sketch. This is the Passing pose. (The quadruped’s hind legs are in the Down pose.)
   TipWhile a single biped (quadruped) part is selected, the PageUp and PageDown buttons move up and down the hierarchy.

   You don’t have to match the sketch accurately: a general idea of the pose is the goal.

   TipIf you find it difficult to select a part of the arms by clicking, use (Select By Name).

   

3. Select the right hand (forefoot), then on the Key Info rollout, click (Set Sliding Key). Do the same for the left hand (forefoot).
   NoteBoth Set Planted Key and Set Sliding Key set IK Blend equal to 1, but only Set Planted Key turns on Join To Prev IK Key. Join To Prev IK Key causes the limb to snap to the pivot set in the previous IK key. Set Sliding Key doesn’t cause the pivot snap; this contributes to a more natural motion for the forelegs.

   One advantage of the ForeFeet toggle is that it lets you set keys such as this for “hands” on the ground plane, as you do for feet.

   NoteThe track bar shows sliding keys in yellow, planted keys in orange, and free keys in gray.
4. Double-click the right clavicle to select the entire arm (foreleg), then on the Copy/Paste rollout, click (Copy Posture).
5. In the Copy/Paste rollout Paste Options group, under Auto-Key TCB / IK Values, choose Copied.

   When Copied is chosen, IK info is pasted along with the new key. When Default is chosen, IK info is not pasted and the new key is a free key, FK rather than IK, which is not what you want for this animation.

6. Go to the last frame (frame 25), and then click (Paste Posture).
7. Go to frame 13, and then click (Paste Posture Opposite).

   Frame 13 is the midpoint of the walk cycle animation: frames 13 through 24 are essentially the same poses as frames 1 through 12, but with the legs in opposite positions. (Frame 25 is the same as frame 1, so that the animation will play as a seamless loop when you preview it in viewports.)

8. Click the Point Of View (POV) viewport label, and choose Right to change the viewport to a Right viewport.

   

9. Go to frame 1, double-click the left clavicle to select all the left arm (foreleg).
10. Click (Copy Posture).
11. Go to frame 25, then click (Paste Posture).
12. Go to frame 13, then click Paste Posture Opposite.

    Now the forearms/legs have the same posture in the extreme poses: the first and last frames of the cycle, and the mid frame.

    TipWhen you use Paste Posture Opposite, don’t be alarmed that a key doesn’t appear on the Track Bar: the original limb is still selected, so you won’t see keys for the opposite limb.
13. Press Shift+Z to undo the viewport change and return to the Left view.

Add the other three poses:

1. Make sure that (Auto Key) is still on.
2. As in the previous procedure, use (Move) and (Rotate) to set up the transitional poses, as follows:
   • Frame 4, Up

     

   • Frame 7, Contact

     

     NoteThe sketches have a bit of perspective, so the left feet appear a bit raised from the ground plane, but as you’re working in 3D, at contact both feet can rest on the ground.
   • Frame 10, Down

     

3. Also as earlier, after you create each pose, select the right forefoot and click (Set Sliding Key), then do the same for the left forefoot.

Check your work by looking at trajectories:

1. Double-click the right clavicle to select all of the right foreleg.
2. On the Key Info rollout, click (Trajectories) to turn int on.
3. Scrub the time slider.

   The elbow trajectory describes an arc, and the foot trajectory describes a rough trapezoid.

   

4. Double-click the left clavicle to see the trajectories for that limb, as well.

Copy poses to the second half of the cycle:

1. Go to frame 4. Double-click the right clavicle to select the entire foreleg, then click (Copy Posture).
2. Go to frame 16, and click (Paste Posture Opposite).
3. (Copy) then (Paste Posture Opposite) from the right foreleg in frame 7 to the left foreleg in frame 19, and from the right foreleg in frame 10 to the left foreleg in frame 22.
4. Repeat the previous three steps, but copying the left foreleg poses to the right foreleg at the same three frames.

Preview your work:

1. Click (Play) to see the animation.

   The quadruped’s forelegs now move in a plausible walk cycle.

2. Click (Stop).

Save your work:

• Save the file as my_quadruped_forelegs.max.