The code below produces cubes in three different positions. To the best of my understanding, it shouldn't. All rotations and translations apply to the object in it's original position at 0,0,0, so the order of these operations shouldn't matter. Can anyone please point out what I missed/misunderstood? rotate ([0,0,90]) translate([800,0,0]) translate([500,0,0]) cube(400,30,100, center=true); translate([800,0,0]) rotate ([0,0,90]) translate([500,0,0]) cube(400,30,100, center=true); translate([800,0,0]) translate([500,0,0]) rotate ([0,0,90]) cube(400,30,100, center=true); -- View this message in context: http://forum.openscad.org/Problem-with-order-of-multiple-translate-and-rotation-tp14447.html Sent from the OpenSCAD mailing list archive at Nabble.com.

billbob123 wrote > The code below produces cubes in three different positions. To the best of > my understanding, it shouldn't. All rotations and translations apply to > the object in it's original position at 0,0,0, so the order of these > operations shouldn't matter. Can anyone please point out what I > missed/misunderstood? > > rotate ([0,0,90]) translate([800,0,0]) translate([500,0,0]) > cube(400,30,100, center=true); > > translate([800,0,0]) rotate ([0,0,90]) translate([500,0,0]) > cube(400,30,100, center=true); > > translate([800,0,0]) translate([500,0,0]) rotate ([0,0,90]) > cube(400,30,100, center=true); Take a step back and think of each one of these operations as linear algebra, matrix multiplications. R1 * T1 * T2 ...is different from... T1 * R1 * T2 ...which is also different from... T1 * T2 * R1 They are only equivalent in trivial cases, e.g. when one is an identity matrix and the other two are their inverse. Andrew. -- View this message in context: http://forum.openscad.org/Problem-with-order-of-multiple-translate-and-rotation-tp14447p14451.html Sent from the OpenSCAD mailing list archive at Nabble.com.

If there was no rotate, then the order of the translates would not matter. If the effect of rotate was to rotate the cube around its centre, regardless of its position, then your intuition would be correct. But that's not what rotate does. "Rotate()" rotates the entire arena of objects around the origin at (0,0,0). So the effect of rotate on each object in the arena depends on the objects position within the arena. On Friday, 13 November 2015, billbob123 <robert.heath16@gmail.com> wrote: > The code below produces cubes in three different positions. To the best of > my > understanding, it shouldn't. All rotations and translations apply to the > object in it's original position at 0,0,0, so the order of these operations > shouldn't matter. Can anyone please point out what I missed/misunderstood? > > rotate ([0,0,90]) translate([800,0,0]) translate([500,0,0]) > cube(400,30,100, center=true); > > translate([800,0,0]) rotate ([0,0,90]) translate([500,0,0]) > cube(400,30,100, center=true); > > translate([800,0,0]) translate([500,0,0]) rotate ([0,0,90]) > cube(400,30,100, center=true); > > > > -- > View this message in context: > http://forum.openscad.org/Problem-with-order-of-multiple-translate-and-rotation-tp14447.html > Sent from the OpenSCAD mailing list archive at Nabble.com. > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org <javascript:;> > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > > >