Procedural Animations using Java3D

Kovalan Muniandy

Accompanying software for Computer Animation: Algorithms and Techniques book by

Dr. Richard Parent

Funded by publisher, Morgan-Kaufmann

MountainView - A camera path animation. Looking at a view of a pseudo-mountain; uses ease-in-out and B-Spline path.

Animation: http://www.cis.ohio-state.edu/~muniandy/cis793/hillview.mpg

VertexList cp = getCurvePoints();

Transform3D viewTrans = new Transform3D();

Transform3D translationTrans = new Transform3D();

Vector3d translate = new Vector3d();

for ( int index=0; index < cp.getCount(); index++ ) {

Vertex v = cp.getAt( index );

translate.set( v.getRealX(), v.getRealY(), v.getRealZ() );

translationTrans.setIdentity();

translationTrans.setTranslation( translate );

viewTrans.set( initTrans );

viewTrans.mul( translationTrans );

vpTransGroup.setTransform( viewTrans );

}

SpeedControl - Just ease animation. A satellite moving to its location: starts slow, accelerates and slows down as it reaches final destination.

Animation: http://www.cis.ohio-state.edu/~muniandy/cis793/ease.mpg

Transform3D xf = new Transform3D();

final Vector3d maxMove = new Vector3d( 700, 0, -20.0 );

Vector3d move = new Vector3d( 0, 0, 0 );

Transform3D moveXf = new Transform3D();

for ( double distance=0.0; distance <= 1.0; distance+=0.002 ) {

double u = doEase? Ease.simple( distance ) : distance;

move.x = maxMove.x*u;

move.z = maxMove.z*u;

xf.set( move );

xf.mul( objectXf );

examineGroup.setTransform( xf );

}

ParametricEase - A spacecraft moving along a curved-path. B-Spline-path, arc length parameterization and ease-in-out.

Animation: http://www.cis.ohio-state.edu/~muniandy/cis793/spaceshp.mpg

VertexList cp = new VertexList(); // List of control points

cp.add( 0, 0, 0);

cp.add( 2.5, 5.0, 8.0 );

cp.add( 5, -5.0, 16.0 );

cp.add( 20.0, 0.0, 55.0 );

CubicBSplineCurve curve = new CubicBSplineCurve( cp );

curve.enableArcLength( doEnableArcLen, 300.0, doEase ); // 300 frames

VertexList points = curve.getPoints();

Transform3D xf = new Transform3D();

Vector3d translate = new Vector3d();

for ( int index=0; index < points.getCount(); index++ ) {

Vertex v = points.getAt( index );

translate.set( v.getRealX(), v.getRealY(), v.getRealZ() );

xf.setIdentity();

xf.setTranslation( translate );

xf.mul( objectXf );

examineGroup.setTransform( xf );

}

Deform - A bird flying. The wings are deformed using Free-Form-Deformation to simulate flapping of wings.

Animation: http://www.cis.ohio-state.edu/~muniandy/cis793/fly.mpg

// Setup FFD around the bird

Point3d x0 = new Point3d( max.x, min.y, max.z );

Vector3d s = new Vector3d( -(max.x-min.x), 0, 0 );

Vector3d t = new Vector3d( 0, (max.y-min.y), 0 );

Vector3d u = new Vector3d( 0, 0, -(max.z-min.z) );

int l=6, m=6, n=6;

FFD ffd = new FFD();

ffd.getLattice().set( x0, s, t, u, l, m, n );

// Get deformed points

// Flap the wings by pulling the grid points of the FFD.

// Right wing: (2, 6, 0) +60z (up) +60y -60z (down)

// Left wing: (2, 0, 0) +60z (up) -60y -60z (down)

int MAX_MOVE=60, INCREMENT=6, ARRAY_SIZE=MAX_MOVE/INCREMENT;

Point3d up[][] = new Point3d[ARRAY_SIZE][];

Point3d down[][] = new Point3d[ARRAY_SIZE][];

// Flip up incrementally

int j=1;

for ( int i=0; i < ARRAY_SIZE; i++ ) {

pt = ffd.getLattice().getGridPt( 2, 6, 0 ); // right wing

pt.z = j;

ffd.getLattice().setGridPt( 2, 6, 0, pt );

pt = ffd.getLattice().getGridPt( 2, 0, 0 ); // left wing

pt.z = j;

ffd.getLattice().setGridPt( 2, 0, 0, pt );

up[i] = ffd.deform( birdPts );

j += INCREMENT;

}

Forward and Inverse Kinematics Animation – Work in progress.