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

5. Interaction with objects

5.1. Biped linked to an object

5.1.1. Preparation

In this chapter, we go to see how bound a biped to an object. The example is the following one : our character practice snowboarding, he is thus completely connected to his board.

Load the file with your Biped

He needs a snowboard (beforehand modelled). We go merge it. In File, click on Merge.

Select the file containing the snowboard (snow.max).

To avoid being disturbed by the mesh, it's better to freeze it. Select it, then do a right click and select Freeze Selection.

It's now necessary to give a surfer's pose to our biped. A surfer is well bent, legs spreaded.

Select the Biped, go in the Animation Panel and develop the Keyframing Tools roll out. Click to Anchor feet, so that they do not move.

In the Track Selection roll out, select Vertical Move tool.

Move down the pelvis as below. (notice that feet are anchored in the position where we put them and don't move any more)

A surfer is oriented in the direction where he goes, so it's necessary to rotate our biped forwards. In the Selection tracks roll out, select the Rotation tool.

Rotate the biped like this

We're now going to adjust feet. Indeed, no surfer has feet so closer. Desactivate the feet anchoring, then space out like this :

Click again on anchor feet so that they don't move any more (they are attached to the snowboard, and don't move). To give him a surfing look, it's necessary that he have legs more spread.

Select the shin bone of the back leg and with the Rotation tool, spread the leg.

Rotate the head in a way that it's looking forward.

It's now necessary to take charge of hands, we're going to put them down. To avoid move them one after the other, we go use the Character Studio Symmetry tool. Select a hand, then click the Symmetry tool.

The other hand is automatically added to selection. Move them down a little.

Place hands as this, to give an effect of balance to our biped.

Finally, Rotate a little the Biped forwards.

Now link the biped to the snowboard. Click the Selection by List tool  and select Bip01.

With the Link tool , link the biped to the snowboard.

Move the snowboard, the biped follows.

5.1.1. Animation

Now that our biped is attached to its snowboard, we're going to make him slide a little. Create an inclined plane, which is for our biped a mountain.

Then, in the top view, create a shape compound of curve which is our snowboard's trajectory.

Do a right click on the animation playtime controls, and set animation's parameters with 400 frames.

Select the snowboard, then in Animation panel, develop Assigne Controller roll out. Select Position, then click Assign Controller ( the question mark).

Choose Path Constraint.

In the constraint parameters, click on Add Path, then select your shape. Select Follow and Bank.

Reorientate if is needed the snowboard in the right direction.

The Biped goes down the hillside by making turns. With the Follow option, Biped is constantly directed in the direction of the curve, and the Bank option it bends in the turns.

Let's add now some supplementary animations so our animation will be more realistic. In snowboard (as in ski), it is necessary to be bent before a turn, to make an extension during the turn and bent again in exit.

Activate the Auto Key button.

Give to our Biped an initiale position, a little bent.

Advance the animation bar so that the biped is just before a turn.

Give to our biped a well bent position.

Advance at the frame where biped is in the middle of the turn.

Give to the biped a tense position

Advance the animation on the turn exit

Give a very bent position to the biped (he weaken)

Another important point is that in snowboard it's necessary to anticipate.Our biped must be directed and look in the direction which he's going before to turn. (To learn to turn in snowboard, it is necessary to look where we want to go, shoulders turned and the rest of the body follows, and finally the snowboard to).

Replace at the same keyframes as for the flexions and the extensions. In the command play zone, click on lock keys.

By clicking buttons Precedent and Next, we advance in the animation key by key and not frame by frame.

On the key before the turn, rotate the biped in direction of the turn.

On the exit turn key, rotate the biped in the same direction of his snowboard.

Play the animation.

5.2. Object linked to Biped

Now we're going to see how an object interact with the biped. Example is the following one : the biped hold a saber and swing it.

Select the Biped, click on Structure, and turn on Prop.

A Prop is a part of the Biped's structure, it can follow a part of the biped like the Center Of Mass or the hand.

Develop the Key Info roll out, double click on the little plus, then on this just on the left of Prop and for Position Space and Rotation Space select the right hand (This which hold the saber).

Then import a saber or blade model in the scene.

With the Link tool , link the saber to the Prop.

Click on the Pose button to exit this mode. Click on Auto keys to animate. 

Move the fingers to make biped grasp the saber.

Give now an initiale position to the biped.

A very simple example of animation : the character turn his head,  brandish his saber and splits the air with it.

Here's the different phases of the animation.

At frame 20, Rotate the head.

At frame 40, Rotate the pelvis and brandish teh saber by moving the hand (the saber follow).

Then Rotate the pelvis to begin the move.

Delay the movement of the arm to give more realism.

Finally rotate the wrist to give the impression that the character accompanies the movement. Move the left foot to give the impression that the biped needs to balance itself because of the movement of slowness of his arm.

Play the animation.