that's basically correct. the (x,y,z) values are the normalized axis vector that the angle rotates about. the rotation follows the right-hand rule (take your right hand and point your thumb in the direction of the vector. the rotation will follow the curl of your fingers -- counter-clockwise).
sean > -----Original Message----- > From: Alejandro Allievi [mailto:[EMAIL PROTECTED]] > Sent: Saturday, October 05, 2002 9:06 PM > To: [EMAIL PROTECTED] > Subject: Re: [JAVA3D] AxisAngle4f and rotations > > > Hi, > > This my **guess**. In the constructor > > AxisAngle4d(double x, double y, double z, double angle) > > (x,y,z) seem to be coordinates of a point. If there is an > origin (0,0,0), > then the axis of rotation is that defined by the line from (0,0,0) > to (x,y,z). For example, AxisAngle4d(0, 0, 1, angle) will make > it rotate about the z-axis. I would also *guess* that the sense of > rotation would vary according to the sign of the angle. > > Let me know if it works svp. > > Alejandro > > >-----Original Message----- > >From: Discussion list for Java 3D API > >[mailto:[EMAIL PROTECTED]]On Behalf Of cyrene lee > >Sent: Saturday, October 05, 2002 11:16 PM > >To: [EMAIL PROTECTED] > >Subject: [JAVA3D] AxisAngle4f and rotations > > > > > >Hi, > > > >I'm still trying to figure out the last argument of axisangle4f. > > > >eg for AxisAngle4d(x,y,z,angle) > > > >the manual says that the angle is the rotation angle about the vector > >(x,y,z) - which way? > > > >Reading the the answers from the forum regarding > axisangle4f, it seems that > >it rotates about the local y-axis. Does that mean that for > the example > >above, y is taken as the y-axis in this rotation? > > > >I've also read that if a rotation abt the local z-axis (I'm > assuming it'll > >be z in the above case) is required, the local y-axis has to > be rotated -90 > >abt the local x-axis - but if the rotation is always done > abt the local > >y-axis, how can you get the local y-axis to rotate about the > local x-axis? > > > >on another note, is there any lib function that can take an > initial point, > >end point and a pivot point and return the required rotation > >required to map > >the initial point onto the end point by rotating abt the pivot point? > > > >Please help. > > > >Thanks > >Cyrene > > > > > > > > > >_________________________________________________________________ > >Chat with friends online, try MSN Messenger: http://messenger.msn.com > > > >============================================================= > ============== > >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". > ==========================================================================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".
