I want to perform an combined rotation in a fixed coordination system.
If you rotate an object around X using a transformation matrix, the object's
coord-system also rotates. A second performed rotation around Y or Z will
rotate around Y' or Z', the new axes. This is called nested rotation (e.g.
flight simulators).
To perform non-nested rotations, i.e. rotation in a fixed coordination
system, you have to recalculate the old Z axis.
i do it like this:
*get the rotation matrix component of the X- rotation.
*invert the matrix (a inverted matrix would do the same rotation in the
opposit direction)
*get the Z-Column (this is the old Z-axis in terms of the new coordination
system)
*rotate around Z-Column
For the 2. rotation I use setRotation(AxisAngle4d). It works fine when I
make rotations divisible through PI/2 (90�).
Rotations like PI/4 don't behave like they should. This is the reason why I
suspect that setRotation(AxisAngle4d) doesn't work well.
can anyone help me please with this problem? Thank you.
roland kofler
related code fragment:
rotationX.rotX(_rot.x);
// rotate about X
transrotation.mul(rotationX);
// rotate about Y
if (_rot.y != 0) {
rotationY = new Transform3D();
rotationX.get(e_);
e_.invert();
e_.normalize();
e_.getColumn(1,help);
System.out.println(" {e_ (.)(1)} :"+help.toString());
e_Achse = new AxisAngle4d(help, (1.0d)*_rot.y);
rotationY.setRotation(e_Achse);
transrotation.mul(rotationY);
}
// rotate about Z
if (_rot.z != 0 ){
rotationZ = new Transform3D(transrotation);
rotationZ.get(e_);
e_.invert();
e_.getColumn(2,help);
System.out.println(" {e_ (.)(2)} :"+ help.toString());
e_Achse = new AxisAngle4d(help, (1.0d)*_rot.z);
rotationZ.setIdentity();
rotationZ.setRotation(e_Achse);
transrotation.mul(rotationZ);
}
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff JAVA3D-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
