For this lesson, we will use the material in this chapter through page 990. We will come back for the rest later. As you have already seen, the biped tool is a humanoid skeleton that can be customized to fit characters in 3DS Max. The text gives us some historical trivia, telling us that there was previously an add on to 3DS Max called Character Studio. The features of this add on are now part of the main program. The biped tool is included in this part of the program.
The text reminds us that the biped must be attached to the character mesh with a skin modifier or a physique modifier. The bones of the biped do not need to fit completely inside the character mesh, since the biped can be set not to render, but it is better to size the bones to the mesh first, then to apply the skin modifier. This will require less modification of the envelopes that enclose the character mesh, as seen in the Quick Start chapter.
To create a biped, you can select Create, Systems, Biped, then drag in one of two ways.
On the modify panel of the biped object, you can name the biped, which will cause all the bones of the biped to inherit that name. By default, each biped you create is numbered and its head is a different color from the last one you made, but they will look a lot alike. Naming them will help tell them apart.
You can also choose from four shapes for the biped: skeleton, male, female, and classic. The text notes that the classic shape was the default in previous versions of the program, and is included to allow the use of older files.
You will have noticed by now that a biped object's right arm and leg are green, and its left arm and leg are blue. This is to help you remember which side is which: there are four letters in left and in blue, five letters in right and in green. These colors are not continued in the fingers and toes of the figure.
We can also observe that the pelvis bone is a shade of yellow because it is in the center or middle of the figure (six letters). The pelvis structure is the root bone, the first bone, of the biped.
As you will see in CAP 202 as well, the biped model may be used with non-human characters that are still four limbed. You can modify most aspects of the structure to accommodate bipedal animals, aliens, and fantasy characters. Once you have made such modifications, you can use the Save File button on the Motion panel to save a new .fig (figure) file. The save button is on the Biped rollout of the Motion panel. It has an image of a 3.5 inch disk on it. This button saves a figure file when figure mode is enabled, and saves a biped animation file (.bip) when figure mode is disabled.
You will want to be aware that the Modify panel for a biped is empty. As indicated above, you make modifications to a biped on the Motion panel. The reasoning given is that a biped is not just a structure, but a structure that is intended to be animated. Look at the Motion panel with a biped selected to see the choices presented in the next image.
The text provides a chart of the number of links that you can use for each body part that can have them. The spine, for example has four links by default, but it may have as few links as 1 or as many as 10. In the Body Type section of the Create Biped rollout, shown on the right, you see that arms can be turned on and off. By default, the biped, as shown above, has only one finger on each hand, one toe on each foot, and no tail or pony tail.
Note, also, the default value of the Ankle Attach field. A value of 1 would attach the ankle at the front of the foot, and a value of 0 would attach it at the back of the foot. The default value (0.2) is a more average human location.
In addition to the Save File button shown above, the Biped rollout has eight other buttons that are explained in a table in the text. Clicking any of the mode buttons changes what other rollouts are available on the panel. At this point you will want to know the following:
There are four mode buttons and six display buttons hidden behind a plus sign below the buttons shown on the image of the Biped rollout above. (Just to the left of the words "Modes and Display") Expanding this plus sign gives you access to these buttons. The mode buttons are covered in a few pages. The display buttons turn visibility on and off for features. The text warns us that we will have to do this to work with crowds. (We will consider crowds in another lesson.)
As is common for this text, the next several pages are too dry to absorb without examples. Let's consider them after we do a tutorial.
Tutorial Notes and Questions
Tutorial 1 (Creating a four footed biped):
The text moves on to animating a biped. We are informed that we can use Footstep mode (for walking, running, jumping), Freeform mode (for any other motion), or use both in the same animation.
Footstep mode allows us to place a series of footprints on the scene for the character to follow.
Each time you click a footstep, it is the next foot in rotation.
Tutorial 2 (Making a biped jump on a box):
In the second tutorial, you use several of the animation tools described above. You will create a box that a biped will walk, run, and jump onto.
Four more pages until the end of this section.
In case you wondered where the Freeform mode button was, the text tells us that we are in Freeform mode when no other buttons on the Biped rollout are selected. Turn off the Footstep mode button in the scene you were just working on and you will see the Key Info rollout appear. This rollout is where you will set and delete animation keys for the biped. There are several more sub-rollouts as well, no doubt a holdover from the Character Studio.
When using Freeform keys for a biped, you will use the timeline as in other animations, and you will be able to manipulate the bones in the viewports, like other animations. Unlike other animations, the keys for the biped are set on the rollout, not with the Set Keys button at the bottom of the screen. However, the keys now appear on the timeline (They did not in Footstep mode.) Think of this as being a way to keep the keys on the timeline from being too complicated to use. Every aspect of a character may be in motion in a keyframe, so it makes sense that we animate a complicated system differently than we animate a prop. This reasoning leads to the Keyframing Tools rollout that allows us to separate tracks for various members of the biped.
The next rollout is the Layers rollout. It is possible to layer animations, allowing the animator to concentrate on animating one or more features in each layer, which combine to a complex animation when all layers are enabled.
As was said above, you save biped animation clips as .bip files, by using the Save File button with the Figure mode disabled. In the second image on this page, the Figure mode is disabled.
The Motion Flow mode button opens the Motion Flow rollout which can be used to combine a series of animation clips into a longer animation.