我可以在开始时更改立方体的颜色。但我想根据变化的值不断动态地改变它。如果我运行以下代码，立方体的颜色将是绿色的，并且不会再次改变，因为这只运行一次。我想知道是否有一种方法可以使用扩展行为的类来更改颜色几次。请让我知道我缺了什么。thanx。
protected BranchGroup getCube() {
BranchGroup bg = new BranchGroup();
BoundingSphere bounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0), 10000.0);
tg = new TransformGroup();
t3D = new Transform3D();
t3D.setTranslation(new Vector3d(-35.0f, -15.0f, 40.0f));
tg.setTransform(t3D);
cc = new ColorCube(3.0);
SimpleBehavior4D3 b = new SimpleBehavior4D3(tg, gui);//changes position of the cube
b.setSchedulingBounds(bounds);
b.setEnable(true);
tg.addChild(b);
QuadArray cube = new QuadArray(24, QuadArray.COORDINATES
| QuadArray.COLOR_3);
cube = (QuadArray) cc.getGeometry();
cube.setColors(0, createGreen());
if (b.liftCapacityStat().equals("full")) {
cube.setColors(0, createRed());
} else if (b.liftCapacityStat().equals("half")) {
QuadArray cube1 = new QuadArray(24, QuadArray.COORDINATES
| QuadArray.COLOR_3);
cube1 = (QuadArray) cc.getGeometry();
cube1.setColors(0, createYellow());
}
tg.addChild(cc);
bg.addChild(tg);
bg.setUserData("Cube");
return bg;
}
以下是代码：
（注意片段
final GeometryArray geometryArray = gi.getGeometryArray();
{
geometryArray.setCapability(GeometryArray.ALLOW_COLOR_READ);
geometryArray.setCapability(GeometryArray.ALLOW_COLOR_WRITE);
}
以及插值器定义为的部分
final Interpolator colchange = new Interpolator() { ....
)
package examples;
import java.util.Enumeration;
import javax.media.j3d.Alpha;
import javax.media.j3d.AmbientLight;
import javax.media.j3d.Appearance;
import javax.media.j3d.BoundingSphere;
import javax.media.j3d.Bounds;
import javax.media.j3d.BranchGroup;
import javax.media.j3d.DirectionalLight;
import javax.media.j3d.Geometry;
import javax.media.j3d.GeometryArray;
import javax.media.j3d.IndexedTriangleArray;
import javax.media.j3d.Interpolator;
import javax.media.j3d.Node;
import javax.media.j3d.PolygonAttributes;
import javax.media.j3d.RotationInterpolator;
import javax.media.j3d.Shape3D;
import javax.media.j3d.Transform3D;
import javax.media.j3d.TransformGroup;
import javax.media.j3d.TriangleArray;
import javax.media.j3d.View;
import javax.media.j3d.ViewPlatform;
import javax.vecmath.Color3f;
import javax.vecmath.Point3d;
import javax.vecmath.Vector3f;
import com.sun.j3d.utils.geometry.GeometryInfo;
import com.sun.j3d.utils.geometry.NormalGenerator;
import com.sun.j3d.utils.universe.MultiTransformGroup;
import com.sun.j3d.utils.universe.SimpleUniverse;
import com.sun.j3d.utils.universe.ViewingPlatform;
public class Example {
public static void main(final String[] args) {
new Example();
}
public Example() {
final SimpleUniverse universe = new SimpleUniverse();
final BranchGroup group = new BranchGroup();
final TransformGroup tg = new TransformGroup();
final BoundingSphere bounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0), 100.0);
final Node blob = createMonster();
{ //to enable rotation
tg.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
tg.setCapability(TransformGroup.ALLOW_TRANSFORM_READ);
}
// {
// tg.addChild(colchange);
// }
// Create rotation to see all sides of the object
final Transform3D btrans = new Transform3D();
btrans.rotX(1);
final Transform3D ztrans = new Transform3D();
ztrans.rotZ(-1);
btrans.mul(ztrans);
final RotationInterpolator ri = createRotation(tg, bounds, btrans, 7000);
tg.addChild(ri);
{
final Interpolator colchange = new Interpolator() {
int colindex = 0;
Color3f[] colors = new Color3f[] { new Color3f(0, 0, 0), new Color3f(1, 0, 0), new Color3f(0, 0, 1),
};
{
final long milis = 9000;
super.setAlpha(new Alpha(-1, Alpha.INCREASING_ENABLE, 0, 0, milis, 0, 0, 0, 0, 0));
super.setSchedulingBounds(new BoundingSphere(new Point3d(0.0, 0.0, 0.0), 100.0));
}
@Override
public void processStimulus(final Enumeration criteria) {
final Alpha alpha = getAlpha();
if (alpha != null) {
final float value = alpha.value();
// System.out.println("alpha=" + value);
final Geometry geo = ((Shape3D) blob).getGeometry(0);
colindex = (int) (value * colors.length);
final Color3f color = colors[colindex];
((TriangleArray) geo).setColor(0, color);
((TriangleArray) geo).setColor(1, color);
((TriangleArray) geo).setColor(2, color);
}
wakeupOn(defaultWakeupCriterion);
}
};
tg.addChild(colchange);
}
tg.addChild(blob);
//
group.addChild(tg);
//
addLight(group, new Color3f(1f, 1f, 0f), new Vector3f(4.0f, +7.0f, -12.0f));
addLight(group, new Color3f(1f, 1f, 1f));
//
final ViewingPlatform viewingPlatform = universe.getViewingPlatform();
final ViewPlatform view = viewingPlatform.getViewPlatform();
view.setViewAttachPolicy(View.NOMINAL_SCREEN);
viewingPlatform.setNominalViewingTransform();
final MultiTransformGroup mtg = viewingPlatform.getMultiTransformGroup();
final TransformGroup vtg = mtg.getTransformGroup(0);
final Transform3D t1 = btrans;
vtg.getTransform(t1);
t1.setScale(2);
vtg.setTransform(t1);
group.compile();
// add the group of objects to the Universe
universe.addBranchGraph(group);
}
private Node createMonster() {
final Shape3D child = createShape();
final Appearance fillAppNode = new Appearance();
final PolygonAttributes pAtt = new PolygonAttributes();
// avoid trouble with clockwise faces
pAtt.setCullFace(PolygonAttributes.CULL_NONE);
pAtt.setBackFaceNormalFlip(true);
fillAppNode.setPolygonAttributes(pAtt);
child.setAppearance(fillAppNode);
return child;
}
private Shape3D createShape() {
final Point3d[] points = new Point3d[] {//
new Point3d(-1, 1, 0), //
new Point3d(1, 1, 0), //
new Point3d(1, -1, 0), //
new Point3d(-1, -1, 0), //
new Point3d(0, 0, 1), //
};
final int[] idxs = new int[] {// the triangle faces
0, 1, 2,//
2, 3, 0,//
1, 0, 4,//
1, 2, 4,//
2, 3, 4,//
3, 0, 4 };
final IndexedTriangleArray ita = new IndexedTriangleArray(points.length, GeometryArray.COORDINATES
| GeometryArray.COLOR_3, idxs.length);
ita.setCoordinates(0, points);
ita.setCoordinateIndices(0, idxs);
//per vertex colors really are per vertex reference
//so each vertex can have a different color for each of its faces
final Color3f[] colors = new Color3f[] {//
new Color3f(1, 0, 1),//
new Color3f(0, 1, 0),//
new Color3f(0, 0, 1),//
new Color3f(1, 1, 0),//
new Color3f(1, 1, 1),//
};
ita.setColors(0, colors);
ita.setColorIndices(0, idxs);
ita.setColorIndices(0, new int[] { 0, 0, 0, 1, 1, 1 });
//
final GeometryInfo gi = new GeometryInfo(ita);
//also generate normal vectors so that the surface can be light
final NormalGenerator normalGenerator = new NormalGenerator();
normalGenerator.generateNormals(gi);
final GeometryArray geometryArray = gi.getGeometryArray();
{
geometryArray.setCapability(GeometryArray.ALLOW_COLOR_READ);
geometryArray.setCapability(GeometryArray.ALLOW_COLOR_WRITE);
}
return new Shape3D(geometryArray);
}
private RotationInterpolator createRotation(final TransformGroup objScale, final Bounds bounds,
final Transform3D btrans, final long milis) {
final Alpha alpha = new Alpha(-1, Alpha.INCREASING_ENABLE, 0, 0, milis, 0, 0, 0, 0, 0);
final RotationInterpolator ri = new RotationInterpolator(alpha, objScale, btrans, 0.0f, (float) Math.PI * 2.0f);
ri.setSchedulingBounds(bounds);
return ri;
}
private void addLight(final BranchGroup group, final Color3f light1Color, final Vector3f ligthDirection) {
{
final BoundingSphere bounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0), 100.0);
final DirectionalLight light1 = new DirectionalLight(light1Color, ligthDirection);
light1.setInfluencingBounds(bounds);
group.addChild(light1);
}
}
private void addLight(final BranchGroup group, final Color3f light1Color) {
{
final BoundingSphere bounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0), 100.0);
final AmbientLight light1 = new AmbientLight(light1Color);
light1.setInfluencingBounds(bounds);
group.addChild(light1);
}
}
}