Here is my code for building a box. I hope this helps. It does not use
utility classes. Its parent class, not provided, defines the appearance and
so forth. Let me know if you need that also.
package com.xith.java3d.geometry.shape;
/**
* Construct a box with 6 shapes and uniform texture based on texture
density as applied to longest side.
* @author David Yazel
* @Copyright 2000, You are free to use for any purpose providing you send
me any bug fixes you make :)
*
*/
import com.sun.j3d.utils.geometry.*;
import javax.media.j3d.*;
import javax.vecmath.*;
public class BuildingBox extends BuildingBlocks {
public BuildingBox(BoundingBox bounds, String textureName, double
textureScale) {
super(bounds,textureName,textureScale);
}
private Vector3f calcNormal( Point3f vertex, Point3f sibling1, Point3f
sibling2 ) {
Vector3f normal = new Vector3f();
Vector3f v1 = new Vector3f();
Vector3f v2 = new Vector3f();
v1.sub(sibling1, vertex);
v2.sub(sibling2, vertex);
normal.cross(v1, v2);
normal.normalize();
return normal;
}
/**
* This method will define a single face of the cube. The two points
* specify the corners of the side, but the points must lay in the same
* plane.
* @param p1 The upper left coordinate of this face
* @param p2 The bottom left cordinate of this face
* @param p3 The top right cordinate of this face
* @param p4 The bottom right cordinate of this face
*/
protected GeometryArray genSide( Point3f p1, Point3f p2, Point3f p3,
Point3f p4,
float textureDensity ) {
// we need to calculate the proper texture scale in the width and
// height of the plane. This is because if we don't do this the
// texture will be distorted.
float textureScaleWidth, textureScaleHeight;
// At this point we don't know what plane we are in, but we are
quarenteed
// all four points are in the same plane, and we know the points are
// specificed in triangle strip mode, so p1,p2 are in same in one dim
// and p2,p4 are also.
float distanceHeight = p1.distance(p2);
float distanceWidth = p2.distance(p4);
// scale the texture given the distance and the density
textureScaleWidth = distanceWidth * textureDensity;
textureScaleHeight = distanceHeight * textureDensity;
// we will build this as a triangle strip array, with normals and
// texture coordinates
int perStrip[] = new int[1];
perStrip[0] = 4;
int numVertexPoints = 4;
TriangleStripArray triangles = new TriangleStripArray(numVertexPoints,
GeometryArray.COORDINATES |
GeometryArray.NORMALS |
GeometryArray.TEXTURE_COORDINATE_2 |
GeometryArray.COLOR_3,
perStrip);
triangles.setCapability(GeometryArray.ALLOW_TEXCOORD_WRITE);
triangles.setCapability(GeometryArray.ALLOW_TEXCOORD_READ);
int count = 0;
// we need to build 4 points. At each point we need to set the
normal,
// texture coordinates and space coordinates.
// define the first vertex
triangles.setCoordinate(0,p1);
triangles.setNormal(0,calcNormal(p1,p2,p3));
triangles.setTextureCoordinate(0,new Point2f(0.0f,0.0f));
triangles.setColor(0,new Color3f(1f,1f,1f));
// define the second vertex
triangles.setCoordinate(1,p2);
triangles.setNormal(1,calcNormal(p2,p1,p3));
triangles.setTextureCoordinate(1,new
Point2f(0.0f,textureScaleHeight));
triangles.setColor(1,new Color3f(1f,1f,1f));
// define the third vertex
triangles.setCoordinate(2,p3);
triangles.setNormal(2,calcNormal(p3,p2,p4));
triangles.setTextureCoordinate(2,new Point2f(textureScaleWidth,0.0f));
triangles.setColor(2,new Color3f(1f,1f,1f));
// define the fourth vertex
triangles.setCoordinate(3,p4);
triangles.setNormal(3,calcNormal(p4,p3,p2));
triangles.setTextureCoordinate(3,new
Point2f(textureScaleWidth,textureScaleHeight));
triangles.setColor(3,new Color3f(1f,1f,1f));
return triangles;
}
/**
* We will be creating the 6 sides as different geometries, thus allowing
* them to be easily referenced, plus we can use multi textures to have
* different textures on different faces
*/
public void genGeometry( Shape3D shape, BoundingBox bounds, float
textureDensity ) {
// variables needed by this method
Vector3f normal;
Point3f p1,p2,p3,p4;
Point3d lowerd = new Point3d();
Point3d upperd = new Point3d();
// get the lower and upper bounds
bounds.getLower(lowerd);
bounds.getUpper(upperd);
// translate them to single floating
Point3f lower = new Point3f( (float)lowerd.x, (float)lowerd.y,
(float)lowerd.z );
Point3f upper = new Point3f( (float)upperd.x, (float)upperd.y,
(float)upperd.z );
// define the front facing side
p1 = new Point3f( lower.x, upper.y, lower.z );
p2 = new Point3f( lower.x, lower.y, lower.z );
p3 = new Point3f( upper.x, upper.y, lower.z );
p4 = new Point3f( upper.x, lower.y, lower.z );
shape.addGeometry(genSide(p3,p4,p1,p2,textureDensity));
// define the back facing side
p1 = new Point3f( lower.x, upper.y, upper.z );
p2 = new Point3f( lower.x, lower.y, upper.z );
p3 = new Point3f( upper.x, upper.y, upper.z );
p4 = new Point3f( upper.x, lower.y, upper.z );
shape.addGeometry(genSide(p1,p2,p3,p4,textureDensity));
// define the LEFT facing side
p1 = new Point3f( lower.x, upper.y, lower.z );
p2 = new Point3f( lower.x, lower.y, lower.z );
p3 = new Point3f( lower.x, upper.y, upper.z );
p4 = new Point3f( lower.x, lower.y, upper.z );
shape.addGeometry(genSide(p1,p2,p3,p4,textureDensity));
// define the RIGHT facing side
p1 = new Point3f( upper.x, upper.y, lower.z );
p2 = new Point3f( upper.x, lower.y, lower.z );
p3 = new Point3f( upper.x, upper.y, upper.z );
p4 = new Point3f( upper.x, lower.y, upper.z );
shape.addGeometry(genSide(p3,p4,p1,p2,textureDensity));
// define the TOP facing side
p1 = new Point3f( lower.x, upper.y, upper.z );
p2 = new Point3f( lower.x, upper.y, lower.z );
p3 = new Point3f( upper.x, upper.y, upper.z );
p4 = new Point3f( upper.x, upper.y, lower.z );
shape.addGeometry(genSide(p3,p4,p1,p2,textureDensity));
// define the LOWER facing side
p1 = new Point3f( lower.x, lower.y, upper.z );
p2 = new Point3f( lower.x, lower.y, lower.z );
p3 = new Point3f( upper.x, lower.y, upper.z );
p4 = new Point3f( upper.x, lower.y, lower.z );
shape.addGeometry(genSide(p1,p2,p3,p4,textureDensity));
}
}
----- Original Message -----
From: Desiree Hilbring <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, September 01, 2000 9:36 AM
Subject: [JAVA3D] Stripcounts
Hi,
I tried to build a box with the GeometryInfo classes the following way:
// Coordinates
// needs to be counter clockwise
Point3f[] coords = new Point3f[4*6];
// front side
coords[0]=new Point3f(eastValue-w,heightValue-c,northValue+l);
coords[1]=new Point3f(eastValue+w,heightValue-c,northValue+l);
coords[2]=new Point3f(eastValue+w,heightValue+c,northValue+l);
coords[3]=new Point3f(eastValue-w,heightValue+c,northValue+l);
// right side
coords[4]=new Point3f(eastValue+w,heightValue-c,northValue+l);
coords[5]=new Point3f(eastValue+w,heightValue-c,northValue-l);
coords[6]=new Point3f(eastValue+w,heightValue+c,northValue-l);
coords[7]=new Point3f(eastValue+w,heightValue+c,northValue+l);
// top side
coords[8]=new Point3f(eastValue-w,heightValue+c,northValue+l);
coords[9]=new Point3f(eastValue+w,heightValue+c,northValue+l);
coords[10]=new Point3f(eastValue+w,heightValue+c,northValue-l);
coords[11]=new Point3f(eastValue-w,heightValue+c,northValue-l);
// back side
coords[12]=new Point3f(eastValue+w,heightValue-c,northValue-l);
coords[13]=new Point3f(eastValue-w,heightValue-c,northValue-l);
coords[14]=new Point3f(eastValue-w,heightValue+c,northValue-l);
coords[15]=new Point3f(eastValue+w,heightValue+c,northValue-l);
// left side
coords[16]=new Point3f(eastValue-w,heightValue-c,northValue-l);
coords[17]=new Point3f(eastValue-w,heightValue-c,northValue+l);
coords[18]=new Point3f(eastValue-w,heightValue+c,northValue+l);
coords[19]=new Point3f(eastValue-w,heightValue+c,northValue-l);
// down side
coords[20]=new Point3f(eastValue-w,heightValue-c,northValue+l);
coords[21]=new Point3f(eastValue+w,heightValue-c,northValue+l);
coords[22]=new Point3f(eastValue+w,heightValue-c,northValue-l);
coords[23]=new Point3f(eastValue-w,heightValue-c,northValue-l);
GeometryInfo gInfo = new GeometryInfo(GeometryInfo.QUAD_ARRAY);
int[] stripCounts = {4,4,4,4,4,4};
gInfo.setCoordinates(coords);
gInfo.setStripCounts(stripCounts);
shape3d.setGeometry(gInfo.getGeometryArray());
shape3d.setAppearance(createAppearance());
I think the box consists of 6 side with 4 coordinates for one side.
But unfortunately I get the following error:
Exception occurred during event dispatching:
java.lang.IllegalArgumentException: StripCounts inconsistent with
primitive
at
com.sun.j3d.utils.geometry.GeometryInfo.checkForBadData(GeometryInfo.
java:1301)
at
com.sun.j3d.utils.geometry.GeometryInfo.getGeometryArray(GeometryInfo
.java:1546)
at app.gwvis.ConstructionSite.makeSite(ConstructionSite.java:138)
at app.gwvis.ConstructionSite.<init>(ConstructionSite.java:55)
at
...
What is wrong or what has to be in Stripcounts when not the number of the
vertices for each shape?
I am lost.
Thanks for your help in advance
Thanks Desiree
PS: I do not want to use the utility box class.
o------------------------------------------------------------------------o
| Desiree Hilbring Institut fuer Photogrammetrie und Fernerkundung |
| Universitaet Karlsruhe, Germany |
| |
| email: [EMAIL PROTECTED] |
| # 0721 6083676 |
o------------------------------------------------------------------------o
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