Tutorial 2: Freeform Biped Animation

Lesson 1: Creating a Simple Freeform Animation

This tutorial is an introduction to using freeform animation techniques with Biped.

In this tutorial, you will animate a biped swimming in place. You'll use freeform animation methods.

You'll animate the biped kicking his legs using rotations and moves, and Copy and Paste Posture Opposite. You'll animate one arm and copy its tracks to the other arm.


Creating a biped and loading a fig file

  1. Create a biped in the Front viewport.

  2. On the Motion panel, turn on Figure mode and load rtgame.fig. This file contains a simple figure with 1 large toe per foot and 1 large finger per hand.

    Biped with one toe and one finger

  3. Turn off Figure mode.

    Tip: You can't animate in figure mode.

  4. Select the biped objects and zoom in using Zoom Extents All.

  5. Zoom out a little using Zoom all.

Starting a freeform animation

You start a freeform animation by clicking the Animate button and transforming any part of the biped. You'll rotate the biped's root object so it is lying prone.

  1. Click in the open space in the Left viewport.

    This deselects all the biped objects and activates the Left viewport.

  2. Press W to maximize the viewport for a closer view of the biped.

    The biped should be in wireframe. Change the shading display of the Left viewport if it is not wireframe.

  3. Turn on Animate .

    The button turns red and the active viewport is outlined in red.

  4. Click Select and Rotate on the Main toolbar.

    Tip: You can select objects by clicking on them in the viewport, or you can select by name. You'll select the biped center of mass by clicking on it.

  5. In the Left viewport, click the small, blue, center of mass object.

    The name Bip01 appears at the top of the command panel.

    The Transform gizmo appears.

    Transform gizmo

    The Transform gizmo lets you easily move, rotate, or scale on a chosen axis. As you move your cursor over the gizmo in the viewport the arrow lines and labels turn yellow.

  6. Move your cursor around, over the center of mass until the Y label turns yellow.

    Since the arrow is pointing at you, you can't see the line.

  7. Rotate the center of mass approximately 90 degrees about the Y axis.

    The rotational values update in the status line below the viewport as you move your cursor.

    The biped rotates so it is lying prone.

    Rotate the biped

    A key appears at the far left of the track bar.

    You are ready to animate the biped swimming. First you'll position the legs.

Posing One Leg

You'll work on the right leg first, setting up its position at frame zero.

  1. Press W so you can see four viewports instead of one.

  2. Select Bip01 R Thigh by clicking the lines of the thigh in the Left viewport.

    Tip: As you hold your cursor over an object in the viewport, the object's name is displayed in a tooltip.

    Select the right thigh.

  3. Rotate the right thigh approximately 30 degrees about the Z axis.

    Rotate the leg up.

    The right foot is pointing straight down. You can rotate it to make it look more natural.

  4. Select and rotate the right foot about 40 degrees about the Z axis.

    Rotate the foot.

    You've just used 3D Studio MAX rotations or "forward kinematics." Next you'll use the Select and Move tool on the foot to move the entire chain of foot, calf and thigh.

  5. Right-click the same foot and select Move.

    Tip: You can choose the transform tools from the Main toolbar or by right-clicking.

    The Transform gizmo arrows switch their display. They are displayed at right angles with Y pointing up and X pointing right.

    Move the foot.

  6. In the Left viewport, use the transform gizmo corner to move the foot a little to the right.

    The knee bends to accommodate the new position of the foot.

    The knee bends.

    You've just used "inverse kinematics." The foot, calf and thigh are linked together in a hierarchical chain. By moving the end of the chain you rotated the lower and upper leg objects.

Animating the Leg

Everything you've done so far has been at frame zero. Now you'll move forward in time and animate the pose at frame 10.

  1. Move the time slider to frame 10.

  2. Move the foot down in the Y axis until the knee straightens out.

    Move the foot down.

  3. Select the right thigh.

  4. Right-click and choose Rotate, then rotate the thigh approximately 13 degrees about the Z axis.

    Rotate the thigh.

    Move the time slider back and forth between frame 0 and frame 10. The leg moves up and down.

Using Copy Posture and Paste Opposite

Now you'll use some specialized Biped tools to pose and animate the opposite leg.

  1. Return the time slider to frame 10.

  2. Double-click the right thigh.

    This selects the entire leg from the thigh down to the toes.

    Double-click to select the leg.

  3. On the Motion panel, under the Keyframing rollout, click Copy Posture.

    The posture of the right leg is copied into a buffer.

    Move the time slider back to frame 0 and choose Paste Posture/Pose/Track Opposite.

    Paste Posture Opposite

    The left leg rotates downward. The right leg hierarchy is still selected.

  4. At frame 0, choose Copy Posture again.

  5. Move the time slider to frame 10.

  6. Click Paste Posture/Pose/Track Opposite again.

    Now the left leg is raised, and the right leg is down.

    Repeat Paste Posture Opposite.

    Move the time slider back and forth between frames 0 and 10 and watch the legs kick.

    Now you'll repeat this process to make the legs kick several times.

Using Paste Posture to create multiple kicks

You can use the Copy Posture tools to quickly copy all the leg keys from one frame to another to create repeated kicking motions.

  1. Move the time slider to frame 0.

    Be sure that Animate is still on.

  2. On the Track Selection rollout Choose Symmetrical.

    This adds the second leg to the selection. Now both legs are selected.

  3. Click Copy Posture at frame 0.

  4. Move to frame 20.

    Tip: You can type in the frame number in the Current Frame time control.

  5. Paste Posture at frame 20.

  6. At frames 40, 60, and 80, Paste Posture.

    Tip: You can quickly move to these frames by typing in the Current Frame Indicator in the time controls.

    You've just made copies of the leg postures. The legs are now in the same poses at frames 0, 20, 40, and 60.

  7. Move to frame 10 and Copy Posture.

  8. At frames 30, 50, and 70, Paste Posture.

    The trackbar displays seven keys for the animation of the legs.

  9. Save your file as myswim1.max.

    Tip: If you have AutoBackup turned on, the software will automatically save your work at regular intervals to a file with a .mx extension.

Animating one arm

When you animated the legs you set two different poses: one with the leg up, and one with the leg down. Animating the arms is more complex. To animate the stroke of an arm, you'll set four poses: