Diplomarbeit (*.pdf - 5,3MB) - Faculty of Computer Science ...

Darüber hinaus gilt es beim Überlappungstest zu beachten, dass möglichst
immer zuerst die Hauptachsen zu testen sind, da sich diese wie gezeigt
einfacher bestimmen lassen. Abbildung 4-26 zeigt die Implementierung des
Überlappungstests.
public class OBBOverlap {
}
final double eps = 1e-6;
double[][] Bf = new double[3][3];
public boolean obb_overlap(double[][] B, double[] T, double[] a,
double[] b) {
Bf[0][0]= Math.abs(B[0][0])+eps;
Bf[0][1]= Math.abs(B[0][1])+eps;
Bf[0][2]= Math.abs(B[0][2])+eps;
Bf[1][0]= Math.abs(B[1][0])+eps;
Bf[1][1]= Math.abs(B[1][1])+eps;
Bf[1][2]= Math.abs(B[1][2])+eps;
Bf[2][0]= Math.abs(B[2][0])+eps;
Bf[2][1]= Math.abs(B[2][1])+eps;
Bf[2][2]= Math.abs(B[2][2])+eps;
}
// Fall 1:
if (TestCase1(0,T,a,b)) return false;
if (TestCase1(1,T,a,b)) return false;
if (TestCase1(2,T,a,b)) return false;
// Fall 2:
if (TestCase2(0,T,a,b,B)) return false;
if (TestCase2(1,T,a,b,B)) return false;
if (TestCase2(2,T,a,b,B)) return false;
// Fall 3:
if (TestCase3(0,0,T,a,b,B)) return false;
if (TestCase3(1,0,T,a,b,B)) return false;
if (TestCase3(2,0,T,a,b,B)) return false;
if (TestCase3(0,1,T,a,b,B)) return false;
if (TestCase3(1,1,T,a,b,B)) return false;
if (TestCase3(2,1,T,a,b,B)) return false;
if (TestCase3(0,2,T,a,b,B)) return false;
if (TestCase3(1,2,T,a,b,B)) return false;
if (TestCase3(2,2,T,a,b,B)) return false;
// sonst Überlappung!!
return true;
private boolean TestCase1(int x, double[] T, double[] a, double[] b)
{
return Math.abs(T[x]) > (a[x] + b[0] * Bf[0][x] + b[1] *
Bf[1][x] + b[2]* Bf[2][x]);
}
private boolean TestCase2(int x, double[] T, double[] a, double[] b,
double[][] B) {
return Math.abs(T[0] * B[0][x] + T[1] * B[1][x] + T[2] *
B[2][x]) > (b[x]+ a[0] * Bf[0][x] + a[1] * Bf[1][x] +
a[2] * Bf[2][x]);
}
private boolean TestCase3(int i, int j, double[] T, double[] a,
double[] b,double[][] B) {
return Math.abs(T[(i + 2) % 3] * B[(i + 1) % 3][j]
- T[(i + 1) % 3] * B[(i + 2) % 3][j]) > (a[(i + 1) %
3] * Bf[(i + 2) % 3][j] + a[(i + 2) % 3] * Bf[(i + 1)
% 3][j] + b[(j + 1) % 3] * Bf[i][(j + 2) % 3] + b[(j
+ 2) % 3] * Bf[i][(j + 1) % 3]);
}
Abb. 4-26 Implementierung des OBB-Überlappungstests
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