A good reference for this sort of thing is Chapter 2 of "Introduction to Robotics Mechanics and Control" by John J. Craig (Addison Wesley). Here's equation 2.66 from section 2.8:
beta = atan2(-r_31, sqrt(r_11^2 + r_21^2)) alpha = atan2(r_21/cos(beta), r_11/cos(beta)) gamma = atan2(r_32/cos(beta), r_33/cos(beta)) alpha, beta, gamma are ZYX Euler angles for the 3x3 rotation matrix r_ij... It's just trigonometry. Good luck with the PhD, Mark > ----- Original Message ----- > From: "Fabrizio NUNNARI" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Tuesday, June 17, 2003 9:48 AM > Subject: [spam: 07.00/05.00] [JAVA3D] Transform3D and angles issue > > > > Hello, > > > > I'm getting confused by the tons of methods of the Transform3D class. > > Is it possible to retrieve the rotational component stored in a matrix? > > I mean "just the three angles around the three axes". > > > > I normally use the (misleading, at least for me) .setEuler(Vector3d > > euler) method. I'm looking for an equivalent .getEuler(Vector3d euler) > one. > > > > I also saw a .set(AxisAngle4d a1). I never tried it, but a corresponding > > .get(AxisAngle4d a1) doesn't exist. > > > > Finally, there is the copule .get/.set(Quat4d rot), but I haven't been > > able to understand the relation between the stored (normalized) values > > and angles value. > > > > What's the difference between .setEuler(Vector3d), .set(AxisAngle4d) and > > .set(Quat4d rot) ???? > > > > > > > > The purpose? I have an object moved/rotated by a TransfromGroup. I want > > to rotate it around a generic axes and then retrieve and print out the > > resulting rotation angles (in the "Euler" form). > > > > Is it possible? > > > > > > thanks, > > Fabrizio NUNNARI > > > > -- > > Fabrizio Nunnari (nunnarif at di.unito.it) > > PhD Student - Computer Science Department - Torino - Italy > > http://www.di.unito.it/~nunnarif/ > > > > > =========================================================================== > > 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". > > > =========================================================================== 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".
