Morphing

[aRTx]

Hi,

Can anyone help how to do it:

Write a program that uses a Morph object and a Behavior object to display an object morphing between a cone and a cylinder.

[xcallmejudasx]

what do you mean display? Is this going to be an image of a cone that redraws itself as a cylinder? Or is it a bunch of data points that show a relationship or what?

Give us more information and how you intend to morph an object and what behavior you have in mind for these objects to have.

[aRTx]

 import javax.vecmath.*;
 import java.awt.*;
 import java.awt.event.*;
 import java.util.*;
 import javax.media.j3d.*;
 import com.sun.j3d.utils.universe.*;
 import com.sun.j3d.utils.geometry.*;
 import java.applet.*;
 import com.sun.j3d.utils.applet.MainFrame;

 public class Morphing extends Applet {
   public static void main(String[] args) {
     new MainFrame(new Morphing(), 480, 480);
   }

   public void init() {
     // create canvas
     GraphicsConfiguration gc =
       SimpleUniverse.getPreferredConfiguration();
     Canvas3D cv = new Canvas3D(gc);
     setLayout(new BorderLayout());
     add(cv, BorderLayout.CENTER);
     BranchGroup bg = createSceneGraph();
     bg.compile();
     SimpleUniverse su = new SimpleUniverse(cv);
     su.getViewingPlatform().setNominalViewingTransform();
     su.addBranchGraph(bg);
   }

   private BranchGroup createSceneGraph() {
     BranchGroup root = new BranchGroup();
     // geometry
     GeometryArray[] geoms = new GeometryArray[4];
     geoms[0] = createGeometry1(0.1);
     geoms[1] = createGeometry1(0.7);
     geoms[2] = createGeometry2(0.5);
     geoms[3] = createGeometry2(0.8);
     Appearance appear = new Appearance();
     appear.setMaterial(new Material());
     Morph morph = new Morph(geoms, appear);
     morph.setCapability(Morph.ALLOW_WEIGHTS_READ);
     morph.setCapability(Morph.ALLOW_WEIGHTS_WRITE);
     Transform3D tr = new Transform3D();
     tr.rotX(Math.PI/2);
	TransformGroup tg = new TransformGroup(tr);
     tg.addChild(morph);
     root.addChild(tg);
     // Behavior node
     Alpha alpha = new Alpha(-1,
     Alpha.INCREASING_ENABLE|Alpha.DECREASING_ENABLE,
       0,0, 8000,0,0,8000,0,0);
     MorphingBehavior mb = new MorphingBehavior(morph, alpha);
     BoundingSphere bounds = new BoundingSphere();
     mb.setSchedulingBounds(bounds);
     root.addChild(mb);
     // light
     AmbientLight light =
       new AmbientLight(true, new Color3f(Color.blue));
     light.setInfluencingBounds(bounds);
     root.addChild(light);
     PointLight ptlight = new PointLight(new Color3f(Color.white),
       new Point3f(0.7f,0.7f,2f), new Point3f(1f,0f,0f));
     ptlight.setInfluencingBounds(bounds);
     root.addChild(ptlight);
     // background
     Background background = new Background(0.7f, 0.7f, 0.7f);
     background.setApplicationBounds(bounds);
     root.addChild(background);
     return root;
   }

   GeometryArray createGeometry1(double h) {
     double r1 = 0.1;
     double r2 = 0.5;
     int m = 20;
     int n = 40;
     Point3d[] pts = new Point3d[m];
     pts[0] = new Point3d(r1+r2, 0, 0);
     double theta = 2.0 * Math.PI / m;
     double c = Math.cos(theta);
     double s = Math.sin(theta);
     double[] mat = {c, -s, 0, r2*(1-c),
                     s, c, 0, -r2*s,
                     0, 0, 1, 0,
                     0, 0, 0, 1};
     Transform3D rot1 = new Transform3D(mat);
     for (int i = 1; i < m; i++) {
       pts[i] = new Point3d();
       rot1.transform(pts[i-1], pts[i]);
     }

     Transform3D rot2 = new Transform3D();
     rot2.set(new Vector3d(0,0,-h/n));
     IndexedQuadArray qa =
       new IndexedQuadArray(m*n, IndexedQuadArray.COORDINATES,
       4*m*(n-1));
     int quadIndex = 0;
     for (int i = 0; i < n; i++) {
       qa.setCoordinates(i*m, pts);
       for (int j = 0; j < m; j++) {
         rot2.transform(pts[j]);
         int[] quadCoords = {i*m+j, ((i+1)%n)*m+j,
         ((i+1)%n)*m+((j+1)%m), i*m+((j+1)%m)};
         if (i < n-1)
	qa.setCoordinateIndices(quadIndex, quadCoords);
         quadIndex += 4;
       }
     }
     GeometryInfo gi = new GeometryInfo(qa);
     NormalGenerator ng = new NormalGenerator();
     ng.generateNormals(gi);
     return gi.getGeometryArray();
   }

   GeometryArray createGeometry2(double h) {
     double r1 = 0.1;
     double r2 = 0.5;
     int m = 20;
     int n = 40;
     Point3d[] pts = new Point3d[m];
     pts[0] = new Point3d(r1+r2, 0, 0);
     double theta = 2.0 * Math.PI / m;
     double c = Math.cos(theta);
     double s = Math.sin(theta);
     double[] mat = {c, -s, 0, r2*(1-c),
                     s, c, 0, -r2*s,
                     0, 0, 1, 0,
                     0, 0, 0, 1};
     Transform3D rot1 = new Transform3D(mat);
     for (int i = 1; i < m; i++) {
       pts[i] = new Point3d();
       rot1.transform(pts[i-1], pts[i]);
     }

     Transform3D rot2 = new Transform3D();
     rot2.rotY(h*2*Math.PI/n);
     IndexedQuadArray qa =
       new IndexedQuadArray(m*n, IndexedQuadArray.COORDINATES,
       4*m*(n-1));
     int quadIndex = 0;
     for (int i = 0; i < n; i++) {
       qa.setCoordinates(i*m, pts);
       for (int j = 0; j < m; j++) {
         rot2.transform(pts[j]);
         int[] quadCoords = {i*m+j, ((i+1)%n)*m+j,
           ((i+1)%n)*m+((j+1)%m),
           i*m+((j+1)%m)};
         if (i < n-1)
         qa.setCoordinateIndices(quadIndex, quadCoords);
         quadIndex += 4;
       }
     }
     GeometryInfo gi = new GeometryInfo(qa);
     NormalGenerator ng = new NormalGenerator();
     ng.generateNormals(gi);
     return gi.getGeometryArray();
   }
 }

and

import javax.media.j3d.*;
import java.util.Enumeration;

public class MorphBehavior extends Behavior
{
  Morph targetMorph;
  Alpha alpha;
  int numWeights;
  double[] weights;
  WakeupCondition trigger = new WakeupOnElapsedFrames(0);

  MorphBehavior(Morph target, Alpha morphAlpha, int numWts)
  {
      targetMorph = target;
      alpha = morphAlpha;
      numWeights = numWts;
      weights = new double[numWeights];
  }

  public void initialize()
  {
      wakeupOn(trigger);
  }

  /**
   * Defines the morphing parameters. See textbook for
   * details.
   */
  public void processStimulus(Enumeration criteria)
  {
      for (int i = 0; i < numWeights; i ++) {
        weights[i] = 0.0;
      }
      float alphaValue = numWeights * alpha.value();
      int alphaIndex = (int) alphaValue;
      weights[alphaIndex] = 1.0 - (alphaValue - alphaIndex);
      if(alphaIndex < numWeights - 1) {
        weights[alphaIndex + 1] = 1.0 - weights[alphaIndex];
      } else {
        weights[0] = 1.0 - weights[alphaIndex];
      }

      targetMorph.setWeights(weights);
      wakeupOn(trigger);
  }
}

but how to do it:
Write a program that uses a Morph object and a Behavior object to display an object morphing between a cone and a cylinder.

[xcallmejudasx]

uhm. the paint method along with fillCone() or fillCylinder(), if those are actual methods. You have to keep redrawing the shape as it changes based on the behavior. you take values like height, radius, etc and use those to add/subtract from the cone values until its a cylinder.

[aRTx]

thnx xcallmejudasx,
but I still can't do it, if you cane write some code pls do it.

thnx very much...