INSIDE 3DS MAX® 7 [Electronic resources] نسخه متنی

Biped Rigs

Bipeds are the most common types of creaturesin the animation world, anyway. This body plan includes not only humans, but also birds, some types of dinosaurs, and any number of cartoon characters, no matter what their species. character studio has thoughtfully included a Biped body type that has much of the work done for you already. Let's take a closer look at Biped.

Creation

Biped is a 3ds max system object, so you find the tools to create the bipedal skeleton on the Create tab > Systems button. In the Object Type rollout, click the Biped button. The creation parameters are displayed in the Create Biped rollout (Figure 15.3).

There are two different Creation methods available, Drag Height or Drag Position. When you choose Drag Height, you simply press the mouse button down in the viewport where you want the feet of the standing Biped to be placed, and then move the mouse to drag out the height at that fixed position. Drag Position lets you click in the viewport and create a Biped of a specified height at the location of your mouse pointer. Moving the cursor around will reposition the Biped.

Biped skeletons come in four flavors of Body Type: Skeleton, Male, Female, and Classic (Figures 15.4 and 15.5).

The lower bottom of the rollout features a laundry list of Biped Body Parameters. These include the number of links in the neck, spine, legs, toes, and fingers. You can adjust the number of toes and fingers and specify whether you want arms, tails, ponytails, or props. These components make up the predefined Biped hierarchy and can be edited later.

These same parameters are also found in the Motion panel if you need to edit them after creating the Biped. character studio is atypical in that its parameters are all located in the Motion panel rather than the Modifier panel.

As with most 3ds max objects, upon creation you can make immediate adjustments to the control panel parameters and those changes will update automatically in the viewport.

Editing the Biped Skeleton

Once you have created a Biped rig in the viewport, you can make changes to the parts so they match the proportions of your character. The default Biped is a rather average-looking mannequin somewhat reminiscent of a crash-test dummy, but there's no reason it can't be a short squat character with a great big head instead.

The workflow that allows you to modify your Biped proportions is the following:

1.	Create the Biped.
2.	With the Biped selected, go to the Motion panel.
3.	In the Biped rollout, click the Figure mode button. Once you are in Figure mode, you can reposition your character or change any of the structure parameters.
4.	In addition to making parameter changes in the Command panel, you can use the Scale tool on the Biped bones to shorten or lengthen them. Use the Scale transform gizmo to scale along one axis to change the length of the bone. Use the other axes to make the bone wider or thicker. Note Unlike the rest of 3ds max, Biped was designed to let you use the Scale tool safely on hierarchical components. Generally, you should never apply a non-uniform Scale operation to a 3ds max bone, or the effects of the scale will be passed down the hierarchy.
5.	For a character with a bilaterally symmetrical body plan, click one limb in the Biped, then click the Symmetrical button in the Track Selection rollout. The opposite limb will be added to the selection of the first limb. This does not make the two limbs symmetrical, but only adds the opposite side's objects to the selection set.
6.	You can reposition some of the Biped components but not others (Figure 15.6). For instance, you cannot move the head away from the neck, but you can move the neck away from the body. You can move the clavicles and the arms away from the body, but you cannot move the upper arm bones away from the clavicles. Figure 15.6. You can move some Biped parts.
7.	You can further adapt the Biped bone parts by simply using Convert to Editable Mesh or Convert to Editable Poly on any Biped skeleton component. Then you can employ all the modeling techniques you are used to employing in 3ds max, such as box modeling or modifiers (Figure 15.7). Figure 15.7. You can change any Biped body part.

Warning:
You can't delete components of the Biped skeleton. If you select the head and click Delete, you will delete the entire Biped. If you don't want the Biped to have a certain part, you should hide it instead. The exceptions to this are the arms, tails, and ponytails. You can turn these off in the Structure rollout by setting the value to 0 or by unchecking the Arms check box.

Figure Mode and Figure Files

When you have finished editing your Biped skeleton, you can save the configuration as a .fig file. As long as you are in Figure mode, the Save File button will create a .fig file for you.

When you create a Biped, there is an option to use the last saved .fig file as a choice for creating new Bipeds. There is also an option to load a .fig file from that part of the UI as well.

When fitting a Biped into a mesh character, it's a good practice to make the character mesh See-Through and then freeze the character. This makes it easier to work on the Biped structure without inadvertently selecting the mesh and lets you easily see how the Biped fits within the mesh's limits (Figure 15.8).

Tip

Don't forget to turn Figure mode off after you're finished editing your Biped bones. When a Biped is in Figure mode, it can't be animated. If you load in a Biped file that doesn't animate, check and see if Figure mode is selected.

If you plan to use the Skin modifier, it's a good idea to make the Biped only slightly smaller than the mesh. The skin envelopes are determined by the size of the bones, so if the Biped bones are significantly smaller than the mesh, the skin envelopes may be too small to affect the mesh vertices. Unlike 3ds max bones, which were developed later, Biped bones don't have the option for front, side, or back fins.