On 12/16/2013 01:02 PM, John Alexander Stewart wrote: > It's been a while since I wrote SLERPing code, but the project I wrote it > for used Quaternions, which I don't think LinuxCNC uses?? Quaternions > certainly made a lot of the internal maths easier. (code was in the > "FreeWRL" VRML/X3D browser) > > *Does* LinuxCNC use Quaternions?
Well, that depends on your meaning of the word "use". If you look at the libnml/posemath/ routines you'll see a lot of internal usage of quarternions for the reason you name but most calls to the routines from the rest of LinuxCNC consist of customary and usual representations. What representations? Well, consider this snippet from posemath.h ----- /* translation types */ struct PM_CARTESIAN; /* Cart */ struct PM_SPHERICAL; /* Sph */ struct PM_CYLINDRICAL; /* Cyl */ /* rotation types */ struct PM_ROTATION_VECTOR; /* Rot */ struct PM_ROTATION_MATRIX; /* Mat */ struct PM_QUATERNION; /* Quat */ struct PM_EULER_ZYZ; /* Zyz */ struct PM_EULER_ZYX; /* Zyx */ struct PM_RPY; /* Rpy */ /* pose types */ struct PM_POSE; /* Pose */ struct PM_HOMOGENEOUS; /* Hom */ ----- You can browse the source code itself but it's faster to read the nearly 15-year old document http://www.isd.mel.nist.gov/projects/rcslib/posemath_examples.html Regards, Kent ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
