Introduction to character studio character studio provides professional tools for animating 3D characters. It is an environment in which animators can quickly and easily build skeletons and then animate them, thus creating motion sequences. The animated skeletons are used to drive the movement of 3ds Max geometry, thus creating virtual characters. Crowds of these characters can be generated using character studio, and animated using a system of delegates and procedural behaviors.

character studio comprises three components: Biped, Physique, and Crowd.

Biped builds and animates skeletal armatures, ready for character animation. You can combine different animations into sequential or overlapping motion scripts, or layer them together. You can also use Biped to edit motion capture files.

Note: Biped does not create character mesh objects. You should create your character mesh before using Biped to create a skeleton for it.

Physique uses the biped armatures to animate the actual character mesh, simulating how the mesh flexes and bulges with the movement of the underlying skeleton.

Note: You can use Physique with other hierarchies beside the biped skeleton.

Crowd animates groups of 3D objects and characters using a system of delegates and behaviors. You can create crowds with highly complex behaviors.

If you are new to 3ds Max, read What You Should Know to Use character studio and Understanding character studio Workflow.

If you are already a 3ds Max user, proceed to Understanding Biped to continue.

To find out about Physique, read Understanding Physique.

To learn about the Crowd system, read Working with Crowd Animation.

What is character studio? character studio is a set of components that provides a full set of tools for animating characters.

character studio lets you create skeletal hierarchies for two-legged characters (called bipeds) that can be animated quickly using a wide variety of methods. If your character walks on two legs, the software provides unique footstep animation that automatically creates movement based on gravity, balance, and other factors.

If you want to animate motions manually, you can use freeform animation. This type of animation is also suitable for characters with more than two legs, or characters that fly or swim. With freeform animation, you can animate the skeleton with traditional inverse kinematic techniques.

You can also animate a biped skeleton by loading motion capture files. You can convert back and forth between these methods to take advantage of their several benefits.

character studio also provides tools for skinning a character using the biped skeleton, or any other type of linked hierarchy.

The software provides a unique ability to separate the motion of the animation from the structure of the character. This means you can animate a giant walking and apply that motion to a tiny elf, or animate a fat character and retarget the same motion to thin one. Using a library of motions, you can animate a character doing hundreds of different actions, as easily as loading a file.

The software provides a comprehensive range of tools for motion editing. You use motion scripting to sequence animations with transitions. Different animations can be overlaid using layers, or blended with the new nonlinear Motion Mixer.

You can use function curve editing, available on the track bar or in Track View, or in the new Animation Workbench, to alter animations. The workbench also provides specialized tools to analyze and correct errors in motion. Finally, the software provides options for creating crowds of bipeds or other objects with a procedural animation system that uses forces and behaviors to drive the characters' motions.

character studio consists of three basic components:

Biped® provides tools to create and animate skeletons. The Physique® modifier associates a skeleton with the character's mesh objects,

so you can control the mesh with the skeleton.

Crowd provides tools to create and animate crowds of animated objects, including bipeds.

What You Should Know to Use character studio

character studio provides you with a broad range of tools for animating virtually any type of character. To expedite your introduction to the product, you should be familiar with the following 3ds Max concepts:

Creation, transformation, and modification of objects Selection of objects through clicking or dragging in viewports, and by using the

Select Objects dialog

Navigation in viewports and changing your viewport configuration

Use of the Track View - Dope Sheet and Track View - Curve Editor, and the trackbar to view and edit animation tracks and keys

For information on these areas, refer to 3ds Max documentation. If you don’t know how to use 3ds Max, do some of the introductory tutorials found online in Help > Tutorials.

Understanding Biped Biped is a 3ds Max component that you access from the Create panel. Once you create a biped, you animate it using the Biped controls on the Motion panel. Biped provides the tools you need to design and animate the figures and motion of characters.

The Biped

The biped skeleton created with the Biped module is a two-legged figure created as a linked hierarchy, and designed for animation. The biped skeleton has special properties that make it instantly ready to animate.

Figure and Keyframe Modes

character studio is designed to interchange motion and characters. In Figure mode, you pose the biped to fit your character model. In Keyframe mode, you animate the skeleton. Motions created for the biped can be saved and loaded onto other biped skeletons with completely different physical characteristics. For example, you could animate a giant ogre, save the animation, and load it onto a small child. Motion files are saved in the proprietary character studio BIP format.

These files can be used in a variety of ways with Motion Flow, the Motion Mixer, or the Crowd tools to combine animation or animate multiple characters at once.

Animating the Biped

There are two primary methods used in creating biped animation: footsteps method and freeform method. Each method has advantages. You can convert from one method to the other, or you can use a combination of both techniques in a single animation. For detailed information, see the sections that follow: Creating Footstep Animation and Creating Freeform Animation.

Biped Properties

The biped skeleton has a number of properties designed to help you animate faster and more accurately.

A human structure—Joints on the biped are hinged to follow human anatomy. By default, the biped resembles a human skeleton and has a stable inverse kinematics hierarchy. This means that when you move a hand or foot, the corresponding elbow or knee orients itself accordingly, and produces a natural human posture.

Customizable for non-human structures—The biped skeleton can easily be made to work with a four-legged creature or an animal that naturally leans forward, such as a dinosaur.

Natural rotations—When you rotate the biped spine, the arms maintain their relative angle to the ground, rather than behaving as if they were fused to the shoulders. For example, say the biped is in a standing position, arms hanging at its sides; when you rotate the spine forward, the biped's fingers will touch the ground rather than point behind it. This is a more natural position for the hands, and this speeds the process of keyframing the biped. This feature also applies to the biped head. When you rotate the spine forward, the head maintains a forward-looking orientation.

Designed for footsteps— The biped skeleton is specially designed to animate with character studio footsteps, which help solve the common animation problem of locking the feet to the ground. Footstep animation also provides an easy way to rough out animation quickly. See the section Creating Footstep Animation.

Understanding Physique

Physique is a modifier that, when applied to a mesh, allows the movements of an underlying skeleton to move the mesh seamlessly, like bones and muscle under a human skin. Physique works on any point-based objects including geometric primitives, editable

meshes, patch-based objects, NURBS, and even FFD space warps. For NURBS and FFDs, Physique deforms the control points, which in turn deform the model. It will attach to any skeleton structure including a biped, 3ds Max bones, splines, or any 3ds Max hierarchy. When you apply Physique to the skin object(s) and attach the skin to the skeleton, Physique determines how each component of the skeleton influences each vertex of the skin, based on settings you specify.

Physique affects a mesh after you click Attach To Node on the Physique rollout and select a root node in the viewports. During the attach process, Physique works its way through all of the children in a hierarchy, starting at the object you select, and creates its own links with associated envelopes for each link it finds. The links created by Physique are referred to within this documentation as the Physique deformation spline. Vertices that fall within envelopes are influenced to follow the links and animate the mesh. Splines and 3ds Max bones can also be added using the Add button in the Floating Bones rollout.

Biped and Physique

When the biped pelvis is selected in the viewports and Attach To Node is turned on, Physique traces its way from the pelvis down the legs to the toes. From the pelvis it also traces its way up through the spine and branches at the collar to the arms, hands, and fingers, and up the neck to the head. A link and associated envelopes are created for each link found. If any other objects, including 3ds Max bones, are linked to the biped, Physique treats them similarly: it creates a new link and envelopes.

Keep this in mind when you use Physique to attach a mesh to the biped; if your character has additional limbs, link 3ds Max bones to the biped for the extra arms before using Attach To Node to create links and envelopes. When Physique is applied and Attach To Node is used, it creates links and envelopes for all the links in the biped, as well as for the linked bones. Objects that should not deform, like skin, but need to be linked to the biped, like a sword, should be linked after Attach To Node is used to link a mesh to the biped. This way, a link and envelopes will not be created for the sword.

Envelopes and Weighted Vertices

Envelopes are the Physique modifier's primary tool for controlling skin deformation; tendons and bulge angles are used to fine tune mesh deformation after envelopes are adjusted. All envelopes have an inner and outer bound (boundary). Vertices falling within the inner bound of a single link receive a full weight of 1.0 from that link. Those falling outside the outer bound receive no weight from that link. Vertices falling between the inner and outer bounds receive a weight between 0 and 1.

Vertices move together with the link that influences them. Where multiple envelopes encompass a vertex, that vertex receives weight from each envelope and follows each link to an average position based on these weights. This weighting from multiple links is considered blending. It is possible that weights assigned to some vertices don’t reach a

total weight of 1.0 or greater. Rather than leaving these vertices behind, Physique by default normalizes them to a value of 1.0.

Adjusting falloff, overlap, scale, and other envelope parameters changes vertex weight distribution across links. This, in turn, changes the way skin behaves as the biped moves. Much of the work you'll do to correct the way skin deforms on a character will be to adjust envelopes.

Deformable and Rigid Envelopes

There are two Envelope types per link, deformable and rigid. Deformable envelopes follow the Physique deformation spline that runs through the joints in the hierarchy, and can be deformed using bulge angles, tendons, and link parameters. Rigid envelopes determine vertex-link assignment based upon the linear 3ds Max link and move in an immobile relationship to the link. Vertices in a rigid envelope, however, are deformed (blended) in the overlap area of other envelopes.

Typically you use deformable envelopes; however, game developers with game-engine restrictions may want to use rigid envelopes exclusively. Both rigid and deformable envelopes can be turned on for the same link. For example, by scaling both envelopes, you could deform the shoulder with a rigid envelope and the armpit with a deformable envelope.

The Number of Links That Can Affect a Vertex

Any number of overlapping envelopes (N Links) can influence vertices. Normally, N Links are preferred. For special purposes such as games requirements, you can limit the number of links (envelopes) that can affect a vertex. The No Blending parameter is similar to the method used in version 1 of the software; a vertex is assigned to only one link.

Physique Workflow

Before Physique is applied, align the biped to the mesh in Figure mode. Use a pose with the arms outstretched so the hands are away from the torso. Save a figure file, so it’s easy to return to this pose whenever you need. Select the mesh and choose Physique in the Modify panel. Turn on Attach to Node and select the root node in the hierarchy (biped Pelvis or root node in a bones hierarchy, not the COM). In the Physique Initialization dialog, click Initialize to create default envelopes based on the links in the hierarchy. The remainder of the work is adjusting envelopes and optionally adding bulge angles and tendons.

Envelope size, overlap, and other parameters are adjusted with the character in an animated position (with Figure mode turned off). By scrubbing the time slider back and forth, you can spot problem areas and adjust the envelopes affecting the problem areas. In Place mode is useful to keep the character stationary during envelope adjustment.

Link parameters, Bulge angles and tendons are the finishing touches. Skin sliding, the amount of twist, and crease blending as a character moves are controlled using link parameters. Bulge angles are used to bulge areas like the biceps, legs and chest relative to the angle created by a link and its child in the hierarchy. Tendons can span multiple links in the hierarchy to stretch and pull a character’s skin.

Understanding Track Editing There are several places to view your animation represented as tracks in 3ds Max. These views include:

Track View - Curve Editor Track View - Dope Sheet

Track Bar

The tracks can be displayed as function curves, or as keys and ranges on a box graph. character studio makes special use of function curve editing capabilities with a customized version of the Track View - Curve Editor called the Animation Workbench.

Biped Curve Editing Using the Track Bar

After creating animation of the biped in the viewport using keyframing tools from the Motion panel, you might need to work on the animation tracks, either to adjust key interpolation for smooth motion or to adjust ranges and affect timing. 3ds Max allows for a number of basic ways to do these tasks for all scene objects using direct key manipulation.

The simplest and most direct access to keys and ranges can be found on the track bar. Keys for selected biped objects are immediately visible there. With some limitations, you can create keys by Shift+dragging in the track bar. Right-clicking any key will display a menu; choosing from this menu will give quick access to key properties such as interpolation controls. This Key Properties dialog is also accessible from a list on the Motion panel > Assign Controller rollout.

A right-click on the time slider also displays the Create Key dialog, which is another quick way to set keyframes.

Selecting any two keys displays the range as a bar beneath the keys. You can reposition this range bar or resize it to adjust the timing of the animation. You can combine accelerator keys, like Ctrl and Alt, with left, middle, and right mouse buttons to extend or stretch the range displayed in the track bar.

You can expand the track bar to quickly display the keys on function curves. From there, you can select and manipulate keys.

Biped Curve Editing in Track View

The same function-curve editing controls are found in Track View. Track View has two modes: Curve Editor and Dope Sheet.

character studio displays function curves for biped components in the Track View - Curve Editor.

Dope Sheet mode displays the footstep tracks and other biped keys as boxes. Here, you cut, copy, and paste keys to create repeated motion. You can use Time Editing in Dope Sheet mode, and cut, copy, paste, and insert time segments, complete with keys, into your animation.

Curve display can help pinpoint troublesome spots in your animation. You can see where a curve has problems, usually corresponding to motion problems in the viewport animation. You move the keys to compensate for the problems.

Understanding the Workbench The Workbench is a curve editor customized for use with character studio. It provides specialized tools for selecting and displaying curves, and also for locating and fixing errors and discontinuities in motion. It is a visualization tool that allows you to see and manipulate quaternion function curves represented as euler angles. Also you can see curves for the the position of a biped body part in any coordinate space.

The Workbench automatically limits selections to just biped body parts and scene objects related to that biped. You can analyze these for errors using a variety of detectors, and fix them using the provided fixers. You can also apply filters to perform operations on different biped body parts to generally affect the animation without error identification.

Function Curve editing for Biped is also available in the 3ds Max Track View - Curve Editor and in the expanded track bar, but without the specialized Workbench tools.

Especially when working with imported motion capture data, you might find that curve editing is difficult using the standard 3ds Max tool set. This is because you might have a key on every frame, so curve manipulation becomes cumbersome and awkward. It is difficult to visually pinpoint where the trouble spots are located. The Animation Workbench offers automatic functions to reduce keys or apply filters to the motion curves to smooth animation.

Understanding Motion Flow

Motion Flow is a tool that graphically arranges clips (motion files), flowing from one motion to the next. You can use a Motion Flow graph to set up a series of clips with transitions between them, which will make the biped perform the series of motions in sequence.

Motion Flow graph with transitions between motion files

You can also create a network of clips on the graph, where each clip has a transition to two or more clips. With this type of graph, you can tell character studio to generate the actual motion sequence for you based on random selection.

Multiple transitions from each clip

A crowd simulation can also be used to generate a motion sequence from this type of graph. Each biped in the crowd chooses from the motions and transitions in the graph based on where they want to go and how fast they need to get there. These factors, in turn, are determined by the crowd parameters you set.

Understanding Crowds

The Crowd system in character studio lets you create realistic simulations using large groups of characters, humanoid and otherwise, that behave and interact with one another by procedural means. You can use it to easily animate scenes containing hundreds of people and/or creatures, all with similar or widely varying sets of behaviors, which can vary dynamically according to other factors in the scene.

At the heart of the system are the Crowd and Delegate helper objects. A single Crowd object can control any number of delegates, which serve as stand-ins for crowd members. You can group delegates into teams, and assign behaviors such as Seek, Avoid, and Wander to individuals or teams. You can combine behaviors with weighting, so that, for example, a crowd member could seek a goal while wandering slightly.

Crowd simulations can range in sophistication from simple and straightforward to highly complex. Aiding at the latter end of the range is the Cognitive Controller feature, which lets you use the scripts to apply conditional transitions to sequences of behaviors. For example, you could tell a delegate to approach a goal until it gets within a certain

distance, and then start moving away. Or you could use a Cognitive Controller to have a delegate move among a series of goals.

Another means of creating complex, dynamic crowd simulations is motion synthesis, which can be used in conjunction with the Cognitive Controller. The Crowd system offers two types of motion synthesis.

When working with bipeds, you use the Motion Flow feature to allow the software to create scripts for the bipeds that match the delegate behaviors.

When working with non-bipedal characters, such as fish or birds, you use Clip Controllers that let you apply different animation segments to various types of motion. For example, a bird might flap its wings quickly while ascending but slowly while flying level, and stop flapping its wings during descent.

One of the most important requirements of crowd simulations is avoidance; realism suffers if characters pass through each other or other objects in the scene. The Crowd system offers a number of behaviors to help achieve proper avoidance. It also provides the Vector Field, a special space warp, that, when applied to an irregularly shaped object, allows delegates to move around the object without penetrating it.

Used in combination, the Crowd-system tools described here can produce an endless variety of interesting, multi-character simulations. The Crowd topics in this manual provide detailed information about every aspect of crowd simulation.

Understanding character studio Workflow Biped, Physique, and the Crowd system work together within 3ds Max to provide a complete set of character animation tools. Although these components can be used in a variety of ways, it is helpful to approach character studio with a basic understanding of how a typical character animation is created.

The following sections provide a brief summary of the basic workflow and related benefits to creating a character with Biped and Physique. You may not use all the following steps, but you’re likely to do them in the following order.

Create Skin Geometry

Create a basic skin shape for your character using any 3ds Max modeling tools and surface types. Be sure to place your character's skin in a neutral pose with arms outstretched and legs spaced slightly apart. You may also want to add sufficient detail to your skin's mesh or control points around joints to facilitate deformation during movement.

Note: Since Physique deformations are based on a volume, you can refine your geometry at a later time with minimal impact on your skin behavior. This means you can create your animation before you’ve built your model if you wish.

Create a Biped Skeleton

Biped automates the creation of bipedal character skeletons. It also lets you introduce significant changes to the skeleton's structure and sizing at any point during your animation without adversely affecting your character's motion. This means you can animate your character without knowing if it is short or tall, skinny or fat. It also means that if the director changes the character’s proportions, the animation will still work.

For more detail on posing a biped skeleton, see Working with Biped.

Attach the Skin

Position the biped character within its modeled skin. Use Figure mode to scale bone lengths and to orient the skeleton correctly within the skin's volume. Scale bone thickness as desired to achieve a good initial fit. Then save a figure file, so it’s easy to return to this pose.

Use Physique to attach the skin geometry automatically to the biped or a 3ds Max bones hierarchy. The attachment is typically made to the root node in the hierarchy: the pelvis object on the biped or the root node on a bones hierarchy, not the center of mass. The attached skin is deformed as the biped or bones hierarchy moves.

The links in the bones hierarchy are used to create a system of 3D envelopes that enclose nearby vertices. Envelopes typically overlap at the parent and child ends of links. Vertices within overlapping envelopes are blended to create smooth skin deformation over joints as the character moves.

Adjust Skin Behavior

Adjust Physique parameters and introduce skin behavior effects to achieve the desired characterization.

Change default envelope shapes by adding cross sections and control points to isolate a more specific volume of vertices for each bone. Use exclusion lists or per-vertex weighting to apply fine-tuning control over individual vertices.

Introduce bulge angles to change muscle shape based on the angle of a particular joint. Create tendons to simulate the motion of tendons under the skin, based on link movements.

Adjust link parameters to change skin twisting, sliding, and creasing as the biped moves. Sliding allows the skin to compress at the biceps and forearm as the elbow is bent. Twisting controls the amount of skin twisting across a joint intersection.

Create extra links using 3ds Max bones and dummy objects for added control. Links can be added to the abdominal area to control compression, for example, or to create a link to animate the chest rising and falling as the character breathes. If a character has extra appendages, 3ds Max bones can be added to animate them. One common usage is to add a bone to animate the jaw.

For further detail, see Working with Physique.

Animate the Biped Skeleton

Once the skin is attached to a Biped structure, you can freely animate the Biped character and see then skin behavior update automatically, based on the current pose.

Tip: Since Physique skin deformation can slow visual playback of your Biped animation, you can temporarily hide the skin object or reduce its resolution in the modifier stack to improve performance.

You can also choose to develop Biped animations in a separate scene entirely, and apply them to your final skinned character when you are satisfied with your final motion.

A biped character is essentially an integrated hierarchy of bones that you can position freely using keyframes, IK goals, and footsteps. You can position a biped character using all the rotation and transformation tools found in 3ds Max.

Many of the 3ds Max coordinate systems can be used to position the biped. Local coordinates are useful to move a limb along its axis (the local X axis is always the axis along the biped limb); world coordinates are handy when there is any confusion regarding which way is up. You can use world coordinates as a home base. In 3ds Max, the world Z axis is always up.

Note: Rotations always occur about the local axis.

Use Freeform Techniques

Biped provides a variety of methods for creating character motion easily. You can use a purely traditional approach by manually creating keyframes in freeform mode for different poses, letting the computer interpolate between joint positions and IK goals.

Use a Footstep-Driven Technique

You can also choose a partially assisted approach by using footsteps and Biped dynamics to help you create a default walk, run, or jump cycle, and then adjust the biped keyframes and footsteps individually.

When using footsteps, biped dynamics helps you by simulating gravity and balance.

Gravity can help in a jumping motion to accelerate a character during the falling period and to bend the legs naturally on landing.

Balance adjusts a character's position when the spine is rotated and keyframed to retain a character's balance.

Dynamics can be turned off on a per-key basis or for the entire animation. The animator can override center of mass keyframes created using Dynamics calculation at any time. Simply set the dynamic properties of these keys or choose Spline Dynamics for keys generated by newly created footsteps.

Convert Between Animation Types

Once you are satisfied with a particular footstep animation and its corresponding dynamic behavior, you can convert it to a freeform animation consisting of a simple combination of keyframes and IK goals. This intelligent conversion gives you control of animation behavior at every frame, for every joint of the character.

Use Layers to Apply Global Changes

Animation layers offer you a powerful tool for introducing global changes to an existing character animation. For example, by adding a layer on top of an existing run motion, and creating a single keyframe with the biped's spine rotated forward, an upright running motion can be turned into a crouched run. Layered changes can be stacked up, allowing you to refine your motion composition and eventually collapse your layers into a standard non-layered keyframe animation.

Use In Place Mode to Control the View

In Place Mode is a tool that lets you keep your biped in view during animation playback. It offers a convenient way of adjusting and adding keyframes to a character without constantly changing your view to follow the character's motion.

Import Motion-Capture Files

Motion-capture files can be imported from the BVH or CSM formats, edited, and saved as BIP files. You can import these files with or without footsteps and dynamics and combine them in Motion Flow mode with other animations.

You can use the supplied motion-capture samples as is or adjust them to suit your needs using Biped's collection of animation tools. The ability to import motion-capture marker files directly into character studio using the CSM file eliminates much of the cost of post-processing optical motion capture data. You can import motion-capture files with an additional prop bone, to define the motion of an object such as a sword or club.

You can also import HTR/HTR2 motion-capture files, as well as TRC files.

Motion-capture files can be imported with key reduction, making for more manageable tracks for subsequent editing.

Use Track View for Keyframe Editing

Track View allows you to edit keys and footsteps relative to the animation time line.

Footstep editing in Track View - Dope Sheet allows you to move footsteps in time. If you need a character to jump higher between footsteps, move the landing footsteps further down in time; dynamics automatically compensate by making the character jump higher to keep it airborne longer.

You can also specify a freeform period in a footstep animation, using Track View - Dope Sheet. This allows you to take advantage of footsteps and dynamics for part of an animation, then switch to manual keyframing during the freeform period. This approach can be particularly useful in animations where there is a mix of animation where the feet are on the ground and then off. Examples of this type of animation include running and diving, or walking and then sitting down.

Keyframe adjustment tools allow you to find the next or previous key for the selected biped body part, use the Time spinner to slide a key back and forth in time, change Tension Continuity and Bias for a key, and to display trajectories.

You can place arms and legs into the coordinate space of another object or the world to simulate interaction with fixed or moving objects. In Freeform mode, for example, putting the character's legs into world space prevents them from sliding or moving when the animator is keyframing the character's center of mass. Putting a character's hand in the coordinate space of a ball allows the hand to move wherever the ball moves.

Many tools in 3ds Max can be leveraged with character studio. For example, the Select and Link tool can be used to attach objects to the biped.

If a character is to pick up and carry an object and then put it down, the Link controller can be used to animate the duration of the attachment. 3ds Max bones can be used to animate character subassemblies, like pistons, and to create extra links for Physique.

Use the Motion Mixer to Mix Animations

You can use the Motion mixer to combine motions on a biped. For example, you could combine a walking motion with a cheering motion, and cause the biped to walk while cheering.

Use Motion Flow to Combine Animations

After you have created and modified various animation sequences, and stored them in biped motion files (BIP format), you can use Motion Flow mode to combine various

motion files into longer animations that can be quickly previewed and edited. Motion Flow mode automatically places the animations end-to-end, allowing you to mix and match both freeform and footstep-driven motion files. Transitions between successive motions are automatically created for you, to provide a first-pass blending between overlapping frames of animation.

The Motion Flow transitions use velocity interpolation to create seamless transitions between clips. You can use the Transition Editor to modify a variety of blending parameters, including transition start frame, length, and angle between clips.

Refining Your Character

Great character animation is a result of many refinements that tune the overall personality of your character. You will find the need to refine progressively both the skinning behavior and the animation timing of your character studio character. Biped and Physique make this iteration process straightforward by fully using the 3ds Max modifier stack and undo methods.

In addition, Biped's ability to map motions between characters makes it easy to interchange great animations with existing characters, and tune their behaviors to achieve true integration of motion with character motivation and personality.

Use Crowds to Animate Groups of Characters

Once you've created animation sequences for characters or other models (such as a bird flapping its wings), you can replicate the models or characters and apply the motions to these groups using the Crowd system. You can also combine them with a wide range of supplied behaviors to create lifelike activities in crowds, such as people streaming through a doorway, street traffic, or birds and fish flocking and avoiding obstacles. You can use Motion Flow mode to create motion clip networks so that characters perform animation sequences appropriate to their current movement and transition smoothly between sequences. And you can use Crowd's cognitive controllers to transition between behaviors based on a variety of criteria. For more on crowd behaviors, see Creating a Crowd System.