Hi,
maybe, you can fix it like this:
PickIntersection info = ...
Vector3d normal = calculateNormal( info.getPrimitiveCoordinates() );
and
private Vector3d calculateNormal(Point3d[] verts) {
if ( verts.length < 3 ) {
return null;
} else {
Vector3d d0 = new Vector3d();
Vector3d d1 = new Vector3d();
d0.sub(verts[1], verts[0]);
d1.sub(verts[2], verts[0]);
Vector3d norm = new Vector3d();
norm.cross(d0, d1);
norm.normalize();
return norm;
}
}
Regards,
Marc
> Hello everybody!
> I'm trying to implement collision detection in j3d 1.2 API using
> picking. The problem is the following: when I use a CylinderShape for
> intersection test with the geometry of the picking scope, I always get a
> null pointer for the normal vector in the intersection point. Any other
> data (closest vertex to the intersection point, its normal, distance
> from the pick shape starting point to intersection point, etc) is
> retrieved correctly. I remark that for terrain following purpose I need
> the normal to the picked polygon (triangle in particular). Does anyone
> have an idea to fix the problem?
> Thanks...
> Max
Marc Nienhaus
) echtzeit AG REALITY BUSINESS
berlin | cologne | san francisco
Marc Nienhaus
Software Engineer (Computer Graphics)
telefon +49 30 884586 0
telefax +49 30 884586 22
http://www.echtzeit.de
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