Character Animation with 3DSMAX [10 mn de lecture - paru le 9/9/2004 11:15:25 AM - Public : Confirmé]

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Maxence MAMY Elève-Ingénieur Supinfo Paris Promotion SUPINFO 2004    Lui écrire    Tous les projets de cet auteur    Le mini-CV de cet auteur

2. The skeleton

Skeleton is the character mecanic. We're going to create bones or generate it with Character Studio, and indicate how it's moving.

2.1. Bones

It's a hierarchical linked system of joined objects each others allowing to animate any sorts of objects, although that its most common use is the character animation (animal or humanoid).

Bones can be animated according to a forward or inverse kinematic, then we create IK or FK solutions.

2.1.1. Skeleton creation

Skeleton is composed of bones that we're going to create and adjust to the mesh.

For a better visibility, it's usefull to have a see-trough mesh. To do that, select the mesh, do a right click, then choose property.

Check the See-Trough checkbox.

To ensure you'll not selecting the mesh by mistake, it's usefull to freeze it. Keep the mesh selected and do a right click, then choose Freeze Selection.

Now we can start bones creation.

In the Create panel, go to Systems, then click on Bones

Choose IKHISolver.

2.1.1.1. The leg

Let's Start by a leg. In the left view, start from the pelvis to the foot. like this :

With the Rotation tool, place correctly the bones to keep them inside the mesh.

You can modify bones appearance to better ajust them with the mesh and give them a much real aspect. 

Turn on SideFins, FrontFin and BackFin.

2.1.1.2. The arm

In the top view create arm's bones, starting from the clavicule to the hand.

Then create the fingers with 3 segment for each.

Modify bones appearance to a better adjusting.

2.1.1.3. The spine

Now choose Spline IKin the Bones roll out, and draw the spine starting from the pelvis to the neck.

2.1.1.4. The head

In the left view, let's Create the neck (one segment) and the head (one segment)

Adjust bones to the mesh.

2.1.1.5. By Mirroring

Click on ... to center the view and after that select Screen as coordonary system

We'll create the other leg and the other arm with the Mirroring tool .

In the dialog window, choose X axis in the Mirror Axis area and copy in the Clone Selection area.

You should have this :

2.1.2. Rigging

2.1.2.1. The legs

We're going to create an IK (Inverse Kinematics) solution linking the upper leg to the ankle. Children bones will move parent bones.

Select the upper leg bone, then go to Animation > IK Solvers, then select HI Solver.

Then click on the ankle bone.

Do it again from the ankle to the foot.

Now create a shape for each foot and aligned  to them. Name them HelpLeftFoot and HelpRightFoot. Theses shapes are helpers to animation. Then, create 4 Helpers Points (turn on Box). The helper on the toe level will be named HelpToe, the one on the heel level will called HelpRotationHeel, the little one will be called HelpHeel and te big one HelpRotationToe. (Add Left or Right according the foot side).

With linking tool , link the Last IK chain at the tip to HelpRotationToe and to HelpToe

Then link the Ik chain on the ankle level to HelpHeel. Link the IK chain in the middle of the foot to HelpHeel.

Now link HelpRotationToe and HelpHeel to HelpToe.

Link HelpToe to HelpRotationHeel and finally link HelpRotationHeel to HelpFoot

In the Create Panel, choose point in helpers section. In the settings, choose box and create one for each leg. Place them juste above the upper legs like this :

2.1.2.2. The arms

Create As the same way the IK chain for the arm, linking the upper arm to the hand.

In the Create panel, in Helpers choose Point. in the settings turn on Box, then create an another one for each arm and move them on the shoulder level (HelperLeftArm and i)

2.1.2.3. The spine

Hide all execpt the spine. Then create 2 hexagons : move one on the pelvis level (HelperPelvis) and another one on the shoulder level (HelperShoulder).

The IK chain will be linked to HelperShoulder, which use to link the arms to the spine.

Pelvis bone will be linked to HelperPelvis, which use to link the legs to the spine.

Then create a third hexagon (HelperSpine) and place it on the pelvis level. After that link HelperPelvis and HelperShoulder to HelperSpine. HelperSpine use to move the entire spine.

2.1.2.4. Finalization

Link the neck bone, HelperLeftArm and HelperRightArm to HelperShoulder.

Link HelperLeftLeg and HelperRightLeg to HelperPelvis.

Create 2 new hexagons : HelperFeet and HelperCharacter (the bigger).

Link HelperLeftFoot and HelperRightFoot to HelperFeet. (If you want to move the feet in same time, to make your character jump for example).

Link HelperFeet and HelperSpine to HelperCharacter. (to move the entire character)

2.2. Character Studio

Character studio was for a long time a plugin and now is a part of 3DSMAX. Indispensable in the video games world this animation tool contains two big modules: Biped and Physique. Biped generates as its name indicates a biped, a preset skeleton.

In the creation panel, go to systems and then click on Biped.

Develop the Structure roll out and set here the parameters of our biped.

Seize 4 for fingers and leave the rest by default.

Once the biped was generated, select and align the pelvis (Center Of Mass) with the mesh

Click the Pose button, to modify and adjust the biped to define its initial pose.

We go settled adjusted a single side of the biped, select the left leg and adjust it to the mesh in Position, Rotation and Scale. For scaling, put the system of coordinates in Local.

Also for the left arm.

For the hand bones, it's possible to move finger (the thumb for example) so  it's adapted to the mesh.

Finally the head.

Now, let's do the right side of our skeleton. Select the bones of the left side (those which are adjusted), then click copy posture, and then on paste to opposite.

Here is the initial pose of your settled biped.

Remark : the biped being generated by Character Studio, the rigging is already made.