Introducing 3ds Max 9 3D for beginners apr 2007 - part 8 pdf

After the biped is fit snugly to the model, you will select all of the components of the model, not the biped, and apply the Physique or Skin modifier in a process often referred to as skinning. The Physique modifier dictates which object, the pelvis of the biped usually, the model is applied to and it is the node where modifications to the skin are accessed. It may take a while to properly test and refine the relationship between the model and the biped to get it to an acceptable level. The final step will be to animate your character. You can accomplish this by using a combination of adding walk, run, and jump cycles to the biped, applying freeform anima- tion, and refining the animation keys in the Dope Sheet. Don’t expect the default walk, run, and jump cycles to create realistic motion. They are just a starting point and must be tweaked to achieve acceptable movements. Character animation is about nuance and sub- tlety, and those artistic touches take a significant amount of time and effort to master. The best way to start is to jump in and examine the tools available. In the next section, you will work with a biped and adjust the parameters and components to modify it. Creating a Biped As stated previously, you should create your model first and then create and modify your biped to fit the model. In this section, however, you are going to examine the procedure for creating and modifying a biped first to provide an understanding of its capabilities. Later in this chapter, we will revisit the methods for adjusting your biped specifically to match a model. Figure 9.2 The default biped Figure 9.1 A bipedal character in the reference position 368 ■ chapter 9: Character Studio and IK Animation 97612c09.qxd 2/26/07 3:00 PM Page 368 Placing a Biped in a Scene Let’s create a Biped system for your scene to get a feel for how CS works. Unlike many of the objects that you’ve created so far, Biped is located under the Systems category the Create tab of the Command panel rather than the Geometry button. Follow these steps to create and adjust a biped: 1. From the Command panel, select Create ➔ Systems ➔ Biped. 2. Click and drag in the Perspective viewport to create the biped. Clicking sets the insertion point, and dragging defines the height of the biped system and defines all of the components. All of the biped’s components are sized relative to the biped’s Height parame- ter. Instead of making a single object, you created 30 visible and 5 hidden objects arranged in a linked hierarchy. All of the elements on the left side of the biped’s body will be blue, and all of the elements on the right side will be green. This is part of the Character Studio col- oring scheme that is carried throughout 3ds Max. 3. Press the H key to see the list of visible objects created with the default biped. All of the objects are indented from the edge of the dialog box, indicating that they are subordinate to, or children of, the objects above them in the list. Close the Select Objects dialog box. If your Select Objects dialog box does not display a hierarchy in an indented format as shown, check the Display Subtree box near the bottom of the dialog. creating a biped ■ 369 97612c09.qxd 2/26/07 3:00 PM Page 369 4. While the biped is still selected, scroll the Command panel to display the Create Biped rollout. This rollout is where changes to the biped’s structure are made. You can increase the number of fingers and toes and the number of links in each to match your model. You can even add a tail or ponytails by increasing the number of links for these parameters, or you can discard the arms altogether. Adding neck links will make your biped taller, but adding spine links will only subdivide the torso area for more control in the midsection. 5. Change the parameters as you like. The biped in Figure 9.3 includes additional fingers and toes, as well as a tail and a ponytail. Figure 9.3 A biped with modi- fied parameters The root object of the hierarchy is named Bip01, for the first biped that you create in a scene, and all the associated objects will have a Bip01 prefix. Changing the name of the object in the Name and Color rollout changes only the name of the root object and does not cascade throughout the hierarchy. Changing the name in the Root Name section of the Create Biped rollout, however, affects all of the objects in the biped. 370 ■ chapter 9: Character Studio and IK Animation 97612c09.qxd 2/26/07 3:00 PM Page 370 Modifying a Biped Bipeds are very generic in appearance, and you will rarely, if ever, use the default biped in an actual animation. Biped’s have a complete set of tools available for modifying their structure and their behavior to match a model. You will have to select an appropriate edit- ing mode to access the appropriate tools to adjust your biped. This section covers the tools used to adjust the size of a biped’s individual elements. 1. Clear your selection set by clicking the Select Object ( ) button in the main toolbar and then clicking on any blank area of a viewport. Nothing in your scene should be selected. 2. Click any part of your biped to select it. Bipeds react differently than other objects: selecting any single component opens the entire object for editing. 3. Click the Modify tab of the Command panel. The purpose of a biped is to create an animation. This is why all of the biped’s parameters, including those that control animation and appearance, are consolidated under the Motion tab of the Command panel. 4. Click the Motion tab of the Command panel to display the first level of rollouts to control a biped. 5. In the Biped rollout, click the Figure Mode button to display the rollouts that pertain to the biped’s configuration, but not to its animation or footstep control. The Figure Mode button turns blue to indicate the current mode that the system is using. 6. Expand the Structure rollout to access the same parameters that were used when you first created the biped to adjust its basic configuration. Make any additional modifications that you choose. 7. Select the biped’s left upper arm. In the main toolbar, click the Rotate transform but- ton and set the reference coordinate system to Local. Most transforms that are applied to a biped are applied in the Local coordinate system so they are relative to the object, rather than the world or the current viewport. In the Body Type area at the bottom of the Structure rollout, you can change the overall appearance of the biped from the default Skeleton to Male, Female, or Classic. The body type has little to do with the biped’s capabilities and is more a matter of preference. creating a biped ■ 371 97612c09.qxd 2/26/07 3:00 PM Page 371 8. Place your cursor over the green Y-axis ring of the Rotate Transform gizmo and drag upward to rotate the upper arm upward, as shown in Figure 9.4. All of the pivot points for the biped elements will be placed at the top of the objects. For example, the upper arm pivots at the shoulder, the lower arm pivots at the elbow, and the hand pivots at the wrist. This is one of Character Studio’s great time savers. 9. Click the Scale transform in the main toolbar. The reference coordinate system automatically switches to Local and then grays out to indicate that the parameter cannot be altered. All scale transforms applied to biped components must be applied in the Local reference coordinate system. 10. Click and drag on the X-, Y-, and Z-Axis handles of the Scale Transform gizmo indi- vidually. The Y and Z handles make the upper arm large or small, causing your biped to get bulked up or thinned out. Dragging on the X handle changes the length of the upper arm. You should observe the changes in all of the viewports while you’re adjusting the scale. 11. Select and adjust the left lower arm, hand, and fingers to suit yourself. Don’t worry about the right side yet; it will be covered shortly. 372 ■ chapter 9: Character Studio and IK Animation 97612c09.qxd 2/26/07 3:00 PM Page 372 12. Select each of the spine links and scale them to give your biped a nice, tapered torso. Dragging the X handle upward will scale the links vertically and push the elements above them upward, increasing the height of the biped. Scaling the top spine link in the positive Z-direction will push the clavicles and all other arm components out- ward, as shown in Figure 9.5. The clavicles are linked to the middle of the top spine link and can be protruded by that link. If necessary, scale the clavicle to extend beyond the top spine link. Figure 9.5 Scaling the top spine link pushes the arms outward. Figure 9.4 Rotating a biped component creating a biped ■ 373 97612c09.qxd 2/26/07 3:00 PM Page 373 13. Select and scale the pelvis to spread the hips out further. 14. Similar to Steps 10 and 11, use the Scale transform to adjust the scale of the bipeds left upper and lower leg and foot. As you can see, creating a biped is fairly simple. You simply click and drag to place the system and drag to set its height and proportionate size. You then adjust the parameters of the structure in the Motion panel. Finally, you position and adjust the size of each of the biped’s components using the transforms. Copying and Pasting Postures Most characters are basically symmetrical with some variation in their surface appearance to make them look a bit less than perfect and a bit more natural. Character Studio allows you to set the structure and form—called the posture—for elements on one side of a biped’s body and then paste those features to the elements on the other side. For instance, when the length, width, and pose of the left arm, hand, and fingers are tweaked as required, the same dimensions and orientations can be pasted to the same components on the right side. You don’t need to model the opposite side independently. There is no self-adjusting relationship between the two sides, so any future changes to one side must be pasted again to the other to maintain any symmetry. 1. Continue with the previous exercise or open CSBiped1.max from the companion CD. 2. Select the biped and access Figure mode if necessary. 374 ■ chapter 9: Character Studio and IK Animation 97612c09.qxd 2/26/07 3:00 PM Page 374 3. Double-click on the left upper arm. Double-clicking on an object selects that object and all the objects below it in the hierarchy—in this case, the lower arm, hand, and all finger joints. 4. Open the Copy/Paste rollout. 5. Postures must be saved as collections prior to being pasted. Click the Create Collection button and then rename the collection from the default Col01 to Left Arm. 6. Just below the blue Posture button, click the Copy Posture button to copy the selected posture to the clipboard. A preview of the copied posture will appear in the Copied Postures area of the Command panel. 7. Click the Paste Posture Opposite button. The size, scale, and orientation of the selected objects will be applied to the reciprocal objects on the opposite side of the biped, as shown in Figure 9.6. 8. Repeat Steps 3 through 7 to copy the posture of the left leg to the right side of the biped. Copied postures are not limited to being pasted within a single biped; they can also be pasted to other bipeds. Simply copy the posture, select any part of another biped, and then click the Paste Posture button. creating a biped ■ 375 97612c09.qxd 2/26/07 3:00 PM Page 375 As you’ve seen in this section, modifying a biped’s appearance and posture is simply the process of selecting one of its components and using the Rotate and Scale transforms to change its size and orientation as needed. In the “Associating a Biped to a Character” section, later in this chapter, you will explore the procedures for fitting a biped to a spe- cific model to ensure a smooth animation setup. Now is a good time to save your scene before you proceed to the next section. Animating a Biped Bipeds can be animated in several ways, including footstep-driven animation and freeform animation. Just as it sounds, footstep-driven animation is the process of adding visible foot- steps to your scene and directing the biped to step onto those footsteps at a particular point in time. Footsteps can be added individually or as a set of walk, run, or jump steps; they can be moved or rotated to achieve the desired result. When using footstep-driven animation, the legs and feet of the biped are not the only things animated; the hips, arms, tails, and all other components are animated too. A short animation sequence can gener- ate hundreds, or even thousands, of animation keys. Footstep-driven animation is often a good starting point, but it is rarely the complete solution to your animation needs. For example, there is no method for turning a biped’s head or raising its arms using footsteps. Even when footsteps are used to create the initial movement of a biped, freeform animation is used to augment and tweak it. Freeform ani- mation is created using the procedures discussed in Chapter 8, “Introduction to Animation,” which includes using the Auto Key method and the Track View in Curve Editor mode. Figure 9.6 Pasting a posture to the other side of a biped 376 ■ chapter 9: Character Studio and IK Animation 97612c09.qxd 2/26/07 3:00 PM Page 376 The animation keys that are added to the selected objects appear in the Track Bar where they can be moved, modified, or deleted to adjust the animation. Some character animators forgo footstep-driven animation altogether and use freeform animation exclusively for the control it gives by creating keys only where the animator chooses and not throughout the biped. In this section, you will explore both the footstep-driven and freeform methods for animating a biped. Moving the Biped into Place As a system, bipeds can’t simply be moved using the Move transform in the Main toolbar. To position one correctly, you must select and move the root object using the Body Verti- cal and Body Horizontal buttons. 1. Continue with the previous exercise or open CSBiped2.max from the companion CD. If you open the CD file, select the biped and enter Figure mode if necessary. In the previous exercise, when you scaled either of the leg elements along the X-axis, the feet of the biped moved off the construction plane where new objects are created. This plane is where the new footsteps will be placed, so you will want the biped’s feet at that same elevation. 2. Maximize the Right viewport and zoom so that you can see the dark, horizontal line indicating the construction plane, the feet, and the pelvis. The pelvis isn’t really important at this point, but the root object located inside of it is. animating a biped ■ 377 97612c09.qxd 2/26/07 3:00 PM Page 377 [...]... wait for you to identify the root object in the hierarchy that controls the mesh ■ 397 97 612c 09. qxd 2/26/07 3:00 PM Page 3 98 3 98 ■ chapter 9: Character Studio and IK Animation 8 Press the H key to open the Pick Object dialog box This method will be easier than trying to click on the object directly in a cluttered scene Select the Bip01 Pelvis object and click the Pick button, as shown in Figure 9. 16 9. .. should be similar to the rendered alien shown in Figure 9. 17 Figure 9. 16 Use the Pick Object dialog box to select the root object in a cluttered scene 97 612c 09. qxd 2/26/07 3:00 PM Page 399 using inverse kinematics ■ 399 Figure 9. 17 The rendered alien during a walk cycle The completed Character Studio Alien exercise can be found in the CS Alien Complete .max file on the companion CD As mentioned at the beginning... “Your First Max Animation,” transforms are passed from a parent object to all of the children objects down the chain Imagine your arm is a system of linked 3ds Max objects; when you pivot your forearm (the parent) at the elbow, your hand (the child) and 97 612c 09. qxd 2/26/07 3:00 PM Page 400 400 ■ chapter 9: Character Studio and IK Animation your fingers (the descendants) are also transformed to maintain... combination to extend the active time segment to include all existing keys Figure 9. 13 Drag the Time slider until the biped is airborne 97 612c 09. qxd 2/26/07 3:00 PM Page 390 390 ■ chapter 9: Character Studio and IK Animation 8 Move the time slider to the frame when both feet are planted before the jump starts Turn on the Auto Key button 9 To prepare the biped to leap, select the Bip01 object and move it downward,... another one, and you must maintain a one-frame gap between same-side footsteps You can’t move a key to a point in time beyond the active time segment nor can you modify keys for footsteps that have been created, but not yet associated to the biped In addition, footsteps must be at least two frames long 97 612c 09. qxd 2/26/07 3:00 PM Page 3 89 animating a biped ■ 3 89 6 The double vertical line in the Dope... not simply hover at a userdefined altitude by moving it in the Z-axis and setting a key, as you would do with most other 3ds Max objects Therefore, increasing the airborne time by increasing the gap between footsteps will boost the height to which the biped rises act against the gravitational force pushing it downward 7 Select the next-to-last Footstep key and drag it to the right to create a gap approximately... neutral position 8 Select all the keys after frame 50 and before frame 100 Delete them by pressing the Delete key This will make room for the new key that you are about to create If animation keys are too close together, the animation could appear jerky 9 Select the key at frame 50, hold the Shift key down, and drag a copy of the key to frame 90 Use the readout at the bottom of the 3ds Max window to drag... 391 97 612c 09. qxd 2/26/07 3:00 PM Page 392 392 ■ chapter 9: Character Studio and IK Animation VIEWING FROZEN OBJECTS If your background color is similar to the default shade of gray that Max uses to depict frozen objects, the model may seem to disappear against the background There are several solutions to this situation: 1 You can go to Object Properties, turn off Show Frozen as Gray, turn on See-through,... the X-axis to lower the biped’s clavicles to match the model’s 3 Move, rotate, and scale the left clavicle as required to place the biped’s shoulder socket in the proper location 4 Scale and rotate the left upper arm and left forearm using the same techniques you used to adjust the biped’s legs 5 Scale and rotate the left hand as required ■ 395 97 612c 09. qxd 2/26/07 3:00 PM Page 396 396 ■ chapter 9: Character... button to turn it off 97 612c 09. qxd 2/26/07 3:00 PM Page 385 animating a biped ■ 385 Figure 9. 11 Rotate the biped’s arm, hand, and fingers to assume a pointing posture Completing the Motion Sequence The CSBiped5 .max file on the companion CD contains the completed scene to this point For additional practice, add keys to the animation of the biped’s arms when it jogs through the run cycle For example, when . model. Figure 9. 2 The default biped Figure 9. 1 A bipedal character in the reference position 3 68 ■ chapter 9: Character Studio and IK Animation 97 612c 09. qxd 2/26/07 3:00 PM Page 3 68 Placing a Biped. Create Multiple Foot- steps button. Figure 9. 7 Moving the biped to the construction plane 3 78 ■ chapter 9: Character Studio and IK Animation 97 612c 09. qxd 2/26/07 3:00 PM Page 3 78 3. In the Create. scale transforms applied to biped components must be applied in the Local reference coordinate system. 10. Click and drag on the X-, Y-, and Z-Axis handles of the Scale Transform gizmo indi- vidually.