Creating and Animating Characters with 3D Studio Max

If you want to create characters and animate them, follow this primer. It will give you several different strategies and discuss some of the underlying problems with creating and animating meshes. This lesson also contains a short discussion and introduction to Hypermatter, a plug-in program that will make your objects deform naturally when they move.

Introduction

If you want to create characters and animate them, read this primer. It will give you several different strategies and discuss some of the underlying problems with creating and animating meshes. Also, it contains a short discussion and introduction to Hypermatter, a plug-in program that will make your objects deform naturally when they move. You can click here to download a self-extracting executable that contains a .max file with the animated character displayed above, a .max file with the skirt with Hypermatter applied, and an .avi showing how Hypermatter makes the skirt swing. You may see errors while loading these .max files if you don't have Hypermatter and Character Studio installed.

Modifying a Standard Primitive Sphere to Create Characters

Any object in 3D Studio Max is made from a collection of triangles, called faces. At the ends of the triangles are small crosses called Vertices. You can edit an object by moving one or more vertices; this will create a unique object. Creating good models this way requires time, patience and skill. Follow the simple tutorial below to find out how to edit vertices on an object.

1. Create a sphere in the Left viewport.
2. From the Edit command panel, click the Edit Mesh button.
3. Click the Select and Move icon from the main toolbar at the top of the screen.
4. In the Front viewport, click and drag a vertex on the sphere to move it.
5. Click and drag an area around the sphere to select more than one vertex, then put your cursor over the selected vertices. Click and drag to move the vertices.
6. To make the vertices move in one direction only, click the Select and Move icon, then one of the Restrict To icons from the main toolbar.

Moving and Deforming an Area of an Object

If you turn the Affect Region checkbox on in the Edit Mesh modifier, you can move one vertex to affect an area of vertices. You can set the number of vertices to be affected by changing the region settings. You can also set how much those vertices are moved in proportion to the vertex that you are moving. For example, nearer vertices are moved almost as much as the moved vertex, while vertices further away are moved less.

1. Click the Affect Region checkbox in the Modify command panel.
2. Click and drag a vertex to see the effect.

Free Form Deformation

An alternative to modifying individual vertices is to use a modifier called Free Form Deformation, or FFD for short. The FFD modifier lets you modify at the object level, but gives you smooth, organic changes to the object.

Although you make changes to the object at the object level (as opposed to at the vertex level), you make those changes at the sub-object level of the modifier level. Thus, to use the modifier, you need to click the Sub-Object button and move the vertices of the modifier.

1. Delete the sphere that you were just using.
2. Create a new sphere.
3. From the Modifier command panel, click the More button to see extra modifiers.
4. Choose 4x4x4 FFD from the list, then click the OK button to close the dialog box.
5. Click the Sub-Object button. This will give you access to the vertices of the modifier.
6. Click the Select and Move icon from the main toolbar.
7. Click and drag the vertices of the modifier to see the effect on the object.
8. Click the Select and Non-Uniform Scale icon from the main toolbar.
9. Select and scale several vertices to see the effect.

Patches

Moving vertices on a mesh is very powerful. It gives you direct control over the most basic elements of an object. As a more organic alternative, create and manipulate a quad patch. Quad patches let you control the curvature of splines on an object. If you can control the splines, you can make curves between the vertices. This gives you a much more organic feel to modifying the product.

1. Use File/Reset to put Max back to start up mode.

2. Click the Create command panel.

3. Open the Standard Primitives list and choose Quad Patch from the list.

4. Click and drag in the Front viewport to create a rectangle for the quad patch.

5. Click the Modify command panel and choose Edit Patch from the list.

6. Click the Sub-Object button if it isn't already active (yellow).

7. Click the Select and Move icon from the main toolbar.

8. Select and drag individual vertices to see the effect on the patch.

When you select a vertex on the quad patch, you will two short lines coming out of the vertex. These lines have small green boxes on the ends. If you use the Select and Move tool to move the green handles, you will see the curvature on either side of the vertex changing. Actually, you can use the Edit Patch modifier on virtually any object. If you plan to export your model to another program, that program is unlikely to support quad patches. If this is a requirement for your project, follow the next exercise to find out how to change the patch back to a normal mesh that can be exported more easily.

Modifying the Modifiers

When you apply a modifier such as Edit Patch or FFD to an object, you create a change from the original object that is stored in a list called the Modifier Stack. Thus, if you applied five modifiers to an object, Max allows you to go back to a previous modifier to change the changes that you made. If , for instance, you taper an object, then use FFD to change its shape, you can call up that modifier and change the taper. When you do this, it may affect the FFD or other modifier that you applied later, and a warning message will appear, telling you that any changes you make to the chosen modifier may affect changes made further up the Modifier Stack. You can choose to OK this warning and run the risk of your other modifer not working properly.

To get at this list of modifiers, click the panel with the name of the last modifier that you used. You will see the list of modifiers that you used on the object. You can then choose one from the list to go back to it to make further changes to that modifier. You can also remove all of the modifiers from the list. This changes the object into what is called an editable mesh. An editable mesh is the object with just the basic elements of an object, these include vertices and faces. All modifiers will be removed.

1. Turn Sub-Object mode off for the Edit Patch modifier.

2. Click the Edit Mesh button from the Modify command panel.

3. Turn Sub-Object mode off for this modifier as well.

4. Click the white panel with the Edit Mesh modifier name in it.

Up until this point, you can go back to any modifier and change the modifications you made. After the next operation, however, you will not be able to see or change modifiers for the object. This may be a good time to save the object to a separate file if you think you will need to modify the modifiers at a later
stage.

Collapsing the Stack

The Modifier Stack is just a list of the modifiers that you applied to an object. Collapsing the stack removes all the modifiers.

1. Click Collapse All from the dialog window and click OK to remove all the modifiers.

Creating Sophisticated Characters

Manipulating objects at the vertex and face levels is all very good, but you can already see that it is time consuming, and requires a lot of skill and patience to make a complex or superior looking object. An alternative to creating an object within Max is to use a device on a physical object and put its surface into
Max. For instance, you could buy a tailor's dummy head, then use a mechanical device called a digitizer to import the surface of the head into Max. The two main methods for doing this are discussed in the following paragraphs.

The first method involves using a mechanical probe. The probe looks like a small crane, and usually has a small sphere or point on the thin end. You will usually need to draw a grid on the surface of the object. To read the surface into a program like Max, you place the probe end on each grid point and press a button or footpedal to read that point into the computer. After you have pointed and clicked on all of the grid points, the software that reads the positions of the probe will connect all the points of the grid together to create a surface that can be manipulated with the above techniques. The more grid points that you use on the object, the more refined and smoother the mesh will be.

The main disadvantage to this method is scale. If you have a 3" high alien figure to scan, the resolution of the probes are in the order of .05". This means that any particular grid point that you have probed may be inaccurate. One solution to this is to take the area of the object that requires more accuracy and to make a bigger scale version. 3D Mechanical probes that can scan a volume of about 2 cubic feet cost around $2500. More accurate devices, and ones that can scan a larger volume, are also available with an correspondingly higher price. The second method produces the same type of Max object that an electro/mechanical probe will produce. However, it uses a laser to read grid points from the surface of the physical model. Either the laser rotates or the model rotates on a plinth to read in all three axis of the object. This method is generally a lot more accurate than a probe, but has an associated cost. The cost of a laser 3D Scanner increases exponentially according to the volume that it can scan. An 18" volume scanner may cost many thousands of dollars, but one that can scan a tank would probably cost many hundreds of thousands of dollars, if not millions. The primary disadvantage of a laser/sonic scanner is that they only scan the exterior surface of an object.

Using Character Studio

After you have the mesh for your character, you can use Max's tools to make it come to life. In general, the mesh that you use for characters is either a single, solid mesh, or a number of meshes linked together. To make a humanoid character like these move elegantly, Kinetix provides some software called Character Studio. This software runs inside Max and uses many of Max's normal functions to work. Although it does not create characters, it does give you some powerful and sophisticated tools to help you animate.

Character Studio Description

Character Studio has three main parts to it. The first part lets you create a character called a biped.

This is a stick-like figure which you apply motion to. The second part of Character Studio enables you to connect the biped and your character mesh together. This part of the program is called Physique. The third part of the program enables you to make the surface of your mesh swell or shrink when motion is applied to simulate muscle bulges.

In this section of the exercise, we will create a biped twice, once to demonstrate free form movement of a biped figure, and then again with a mesh loaded, so we can apply the biped to the mesh using Physique. After that, we can load a biped that is already connected to a mesh and apply some previously stored animation to both so you can see the effects.

Creating a Biped

All motion that your character will perform is applied to the biped. Initially, you create a series of left and
right footsteps on the ground for the biped to place its feet on. The program is mainly footstep driven, but can be used for animation where you control all motion. First we will look at free form animation, then we will create some footsteps and apply them to the biped to make it walk, dance and climb stairs. Note: In the following section, you make a biped character. Do not make it in the same place as the Joe mesh, but rather alongside him, so that you can make a biped approximately the same size.

1. Reset Max from the File/Reset option in the main menu.

2. Click the Create command tab if it isn't already active.

3. Click the Systems icon, on the line below and to the right of the Create command tab.

4. Click the Biped button.

5. Place your cursor at the bottom of the Front viewport at the same level as the soles of Joe's feet. Click and drag to create two points. The first point will be between the feet of the biped figure, and the second point will be at the top of its head, level with the top of Joe's head.

6. Let go of the cursor. After a couple of seconds, the biped figure will generate.

Animating the Biped

The biped figure is connected together. You will find that when you try to move it, its limbs move with the
constraints of motion that you would expect to see on a human.

1. Click the large gray Animate button at the bottom of the screen to turn it on (red).

2. Click and drag the Time Slider button just below and to the left of the viewports. At the moment, it should say 0/100 to show that we are currently on frame 1 of 101 frames in an animation.

3. Drag the Time Slider to frame 25 (25/100).

4. Click the Select and Move icon from the main toolbar.

5. Select the right hand of the biped and move it.

6. Select and move the left foot of the biped to raise it a little.

7. Select and rotate the left thigh to bend the leg.

8. Select the biped root object by name by clicking the Select by Name icon from the main toolbar, then choosing Bip01 from the list.

9. Click the Lock icon at the bottom-center of the screen to prevent de-selection of the root object.

10. Move the biped down.

11. Unlock the selection.

12. Drag the Time Slider to frame 50 and make further changes.

13. Continue to make changes on other frames to create an animation.

14. Click the Play button at the bottom-right of the screen to see your animation.

Loading a Character File

Before creating a biped, you should have a character mesh already on your screen so that you can fit the biped's size to fit your object.

Note: Character Studio is designed to work with either a single mesh or a number of mesh objects linked
together.

1. Click the File/Open main menu item.

2. Open the project file that came as part of the download for this project.

Modifying a Biped

You can change most of the sizes of limbs that the biped is made from. To do this, you must enter a special mode of the biped called Figure mode. You change into this mode from the Motion command panel, by clicking on an icon called Figure Mode. Click it before you make any changes to the size or scale of objects in the biped.

Figure mode is a special posture for changing the biped to fit your mesh. In general, you do this while your character is active on the screen but has no motion applied to it. Any motion applied to your mesh character will be lost after you have fitted the biped to it.

1. Select any part of the biped figure.

2. Click the Motion command panel to open it.

3. Click the Figure Mode icon to active it. You may have to zoom into the biped.

4. Select the entire mesh for Joe.

5. From the Display command panel, open the Freeze section and click Freeze Selected to disable selection of the mesh.

6. Select and Move the Bip01 root object and move it as near as you can to the same position as the Joe mesh.

7. Click and hold on the Select and Scale icon from the main toolbar.

8. Choose the second icon down. If you look at the bottom-left of your screen, you will see the name of the icon is Select and Non Uniform Scale.

9. Choose part of the biped that you want to scale.

10. Click the appropriate Restrict to icon from the top of the main toolbar (either X or Y or Z). You will know that it is the correct direction for scaling when you see one of the lines of the small XYZ axis tripod on the selected object turn red.

11. Click and drag to change the size of the biped part.

12. Click the Select and Rotate icon from the main toolbar.

13. Select and rotate the arms of the biped to closely fit the mesh.

Linking a Mesh to a Biped

To connect the biped to the mesh, you select the mesh first, then apply a modifier to it called Physique. You then choose the root object on the biped to link to, and Character Studio takes a guess at which parts of the mesh to connect to which parts of the biped. After you have linked the two in this way, you will need to change which vertices on the mesh get applied to each link. If you do this, when the biped moves, the mesh will move appropriately.

When you connect the biped and the mesh, you tell it that certain parts of the mesh are allowed to flex. The vertices that you allow to flex are called deformable vertices, and the ones that cannot flex are called non-deformable vertices. There is a third type of vertex, called a system vertex, but these should not be changed unless they are assigned incorrectly.

1. Unfreeze the mesh.

2. Select the mesh.

3. Zoom into the pelvis area of the mesh.

4. Choose Physique from the More section of the modifiers in the Modify command panel.

5. Click the Assign to Node icon from the command panel.

6. Click the root object of the biped. If you do this correctly, you should see yellow lines that are the internal bones, or links, of the biped. These lines are linked to the vertices of the mesh, and once they are generated you can change the vertex assignments, as demonstrated in the next section.

Changing Vertex Assignments

You will always need to change which links of the biped skeleton are linked to which nodes of the mesh. You do this by selecting the vertices of the mesh, then, using the Physique modifier, assigning them to the correct link at the Sub-Object level for vertices.

Red vertices are deformable, and will squash when the biped bends. Green vertices are not deformable,and will retain their distance from the link and never squash.

1. Click Sub-Object in the Modify command panel.

2. Choose Vertex level.

3. Select the vertices that you want to change.

4. Click the Assign to Link button at the bottom of the Modify command panel.

5. Choose the type of vertex that you want to assign.

6. Click the link that you want to assign those vertices to.

Applying Motion to the Biped Using Footsteps

Once you have done all the vertex assignments, you can animate the biped, and its motion will be transferred to the mesh.

1. Open the file on your computer called debbie. This file has the biped and vertices fitted.

Creating Multiple Footsteps

1. From the Motion command panel, click the Footsteps icon to enter Footstep mode.

2. Click the Create Multiple Footsteps icon.

3. Change the number of footsteps to 6.

4. Click OK to create the footsteps.

Activating the Footsteps

To make the biped move along the footsteps, you need to activate them first.

1. Click the Activate Inactive Footsteps icon from the Modify command panel.

2. Click the Play button to see the animation.

Creating More Footsteps

You can easily append more footsteps to the previous ones by creating more footsteps, then activating them.

1. Click the Create Multiple footsteps icon from the command panel.

2. Type 5 for the footstep height.

3. Change the number of footsteps to 8.

4. Click the OK button.

5. Click the Activate Inactive Footsteps icon.

6. Play the animation.

Changing Footsteps

You can easily change the footsteps by selecting them and then making changes. Wherever you place a foostep, the biped and mesh will try to step on them, unless they are out of range, in which case you will see strange motion applied.

1. Click and drag in the Top viewport to select the last 8 footsteps. They will be selected when you see each step has an XYZ axis tripod.

2. In the command panel, click and drag the Bend spinner to curve the footsteps.

3. Click the Play icon to see the animation.

Applying Motion to the Biped Using a Loaded Footstep File

Character Studio comes with a set of previously defined set of footsteps, or you can create your own then apply them to any character/biped that you create.

1. From the Footstep command panel, click the Load Biped File icon.

2. From the Cstudio folder, choose ChaCha.bip.

3. Play the animation in the Perspective viewport.

When you load a Bip file, the footsteps in the animation become overwritten.

Keyframing the Biped

At any time during the animation of the biped, you are free to create additional movement on the biped by standard Max keyframing. Click the large, gray Animate button, move to the appropriate frame, and then move the biped. The only restriction is that you cannot change the feet while they are actually on a footstep.

Motion Capture

For the most realistic movement that you can get on a character, you can scan a real person's movement and put it onto a biped. Several manufacturers offer solutions where you place sensors on a person's joints, then they use a special type of scanner to read the movements of the person as they move. The data can then be input directly onto the biped or skeleton. Although this can be very lifelike, there are several problems:

If you are animating a heavily built alien, its limb proportions may not be suitable for the joint positions captured from the performer.

  • The performer must move similar to the way acharacter would. For example, if you are animating a small, thin girl mesh, the performer must move like the girl would.

  • Some systems attach the sensors on the surface of the limbs of the performer. The motion is then applied to the center of the limbs on the mesh. This will generate inaccuracies. Problem areas such as the hips and shoulders create unrealistic movement, out of sync with the mesh.

  • Motion data is generally captured for each frame in your animation. Therefore, if you have 16 or 18 sensors on the performer, multiplied by the number of frames captured (at 30 frames per second of animation), this can create a huge quantity of data that cannot be reduced without losing smooth movement.

Interaction with Other Objects in the Scene

Character Studio is quite capable for interacting with objects in the scene. You use the a blend of biped motion with object motion to put the two together so that the biped is influenced by the position of an object.

Using Plug-ins with 3D Studio Max

Character Studio is one example of a sophisticated plug-in. It runs entirely inside Max, and looks like an extension to Max. Hundreds of other plug-ins are available. One other example is Hypermatter, from Second Nature. Many other plug-ins can be found on the Internet through the world-wide-web. Another good one for facial animation is Smirk, from Lambsoft.

Hypermatter

Hypermatter lets you change the appearance of the physical properties of an object. For instance, if you create a sphere, you can assign fluid-type properties to it so that when it hits a wall, it squashes realistically.

1. Create a sphere in the Top viewport.

2. Turn the Animate button on.

3. Drag the Time Slider to frame 100.

4. Move the sphere to the right of the viewport.

5. From the Create command panel, click the Standard Primitives drop-down list and choose Second Nature.

6. Click the Hypermatter button.

7. Click the Solidify button.

8. Play the animation.

The original sphere has been hidden, and a substitute is now animated to drop through the floor.

1. Stop the animation.

2. From the command panel, click the Walls button.

3. Click and drag to create a box larger than the sphere.

4. Click the Make Walls Global checkbox in the command panel.

5. Select and move the box so that it fully encloses the sphere on frame 0.

6. Play the animation.

The default property of the sphere can be changed to give it different properties.

1. From the Modify command panel, choose the Sub-Object button.

2. Click the Substance Editor icon.

3. From the drop-down list choose a different type of substance.

4. Play the animation to see the changed effect.

Sub-Object Hypermatter

You can change the properties only of part of an object if you want to change that sub-part's reaction to movement. In the following simple example, we create a swirling skirt from a simple lofted object.

1. Open the File called Skirt.

2. Select the Object.

3. Play the animation. You will see some simple rotations of the skirt.

4. Choose Second Nature from the Standard Primitives drop-down list in the Create command panel.

5. Click the Hypermatter button.

6. From the Modify command panel choose Sub-Object, then Geometry.

7. Select the lower two-thirds of the skirt by clicking and dragging a window around it, the selected part should turn red, if all of the skirt turns red do the selection again so that you have some vertices at the top of the skirt unselected or white.

8. From the Modify command panel, click the Solidify Sub Object button.

9. Play the animation.

Forces on Hypermatter Objects

By default, gravity takes over in an Hypermatter animation. This is due to forces applied in Hypermatter.
You can turn these forces off.

1. From the command panel click the Forces icon.

2. In the Z field, change the force number from -100 to 0.

3. Play the animation again.

4. You can use the Substance Editor to change the properties of the sub-object to provide a more or less realistic swirling motion of the skirt.

Play the review of the animation downloaded with the project file to see the end result. Hypermatter can also be used in Collision Detection mode so that two objects will not intersect each other during animation. You could use this property, for instance, to place the skirt onto your character animation so that the skirt swirls and keeps on the exterior of the mesh object.

 

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