All I want to do is have a cube with all corners intersecting the axis, thus, it needs to be rotated. Rotating it 45 degrees like this should work, I thought: rotate([45, 45, 45]) cube(20, center=true);
But it doesn't! I don't know why but the corners of the cube are not located on any of the axis. Seems so simple to me, yet I can't understand why it's not working... So, question! How do I rotate a cube so all corners will be at one of the three axis? With kind regards, Wim, W.A. ten Brink.
With kind regards,
Wim, W.A. ten Brink 
I don't think it is geometrically possible for a cube to do this. A cube has 12 vertexes, and you want 8 of those vertexes to be aligned with the axes. It's not possible without warping the cube into an irregular hexahedron. You can do this with an octahedron, which has 8 vertexes. On 31 March 2016 at 19:47, Wim ten Brink <[hidden email]> wrote: All I want to do is have a cube with all corners intersecting the axis, thus, _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org 
I'm not sure where the 12 vertices comes from, as I count eight, four for the top face and four for the bottom face, which are common to the sides, of course.
For the original post, though, I don't believe what you seek is possible. Consider that if you slice a cube across any plane that meets your requirements, you do not get a square. I took four points that would represent two of the axes, but they are not coplanar, so you can't make them fit on those axes. A regular octohedron would fit, but would not be a cube, of course. It has six vertices, to match the axis intersection points. Wim ten Brink, am I missing something with the vertex counts? They don't match yours but geometry is challenging me at the moment. 
In reply to this post by Wim ten Brink
Okay, dumb question... There are three axis, thus making 6 points where the cube can go through an axis. But the cube has 8 corners so it will never touch the axis with all sides...
So, how to create a shape that does have all corners on an axis? Oh, well... This is what I was actually looking for: Problem solved.
With kind regards,
Wim, W.A. ten Brink 
Or: cylinder(r1=10,r2=0,h=10,$fn=4); scale([1,1,1]) cylinder(r1=10,r2=0,h=10,$fn=4); 20160331 23:05 GMT03:00 Wim ten Brink <[hidden email]>: Okay, dumb question... There are three axis, thus making 6 points where the _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org 
Now that is an interesting use of a negative 'scale' never thought to use it like that...

cylinder(r1=10,r2=0,h=10,$fn=4); mirror([0,0,1]) cylinder(r1=10,r2=0,h=10,$fn=4); Is more readable I think. On 1 April 2016 at 07:02, macdarren <[hidden email]> wrote: Now that is an interesting use of a negative 'scale' never thought to use it _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org 
In reply to this post by Ronaldo
Nice! Never considered that option. Normally, I expect round objects with cylinders. :)
Still like my own, though, since I actually want those rounded edges. But this is something to remember.
With kind regards,
Wim, W.A. ten Brink 
Rounded hull() { sphere(1); union() { cylinder(r1=10,r2=0,h=10,$fn=4); mirror([0,0,1]) cylinder(r1=10,r2=0,h=10,$fn=4); } } 20160401 5:24 GMT03:00 Wim ten Brink <[hidden email]>: Nice! Never considered that option. Normally, I expect round objects with _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org 
Sorry. That is what I mean:
minkowski() { sphere(1); union() { cylinder(r1=10,r2=0,h=10,$fn=4); mirror([0,0,1]) cylinder(r1=10,r2=0,h=10,$fn=4); } } 
This post was updated on .
In reply to this post by Ronaldo
huh...that last doesn't work for me at all...I can kinda round part of the primary object if I translate the sphere out to the coroner of the object but still it only rounds part of it...
I admit I don't know much about hull(), so maybe there is some way to make it work over the entire thing. To my mind I would need a sphere at each vertex. maybe minkowski() instead of hull()? edit: beat me to it...at least it wasn't my own misunderstanding...:) 
In reply to this post by Ronaldo
On 01. april 2016 21:11, Ronaldo wrote:
> Sorry. That is what I mean: > > minkowski() { > sphere(1); > union() { > cylinder(r1=10,r2=0,h=10,$fn=4); > mirror([0,0,1]) cylinder(r1=10,r2=0,h=10,$fn=4); > } > } Interesting ... so minkowski does not really care about the specification of the object type (cylinder), only the discretized result. It appears to me to be a major hack to use cylinder to specify a cone which becomes a pyramid and then use minkowski on that.... Carsten Arnholm _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org 
There are no true spheres, cylinders, circles or curves in OpenScad once the renderings starts. All the geometry is represented by polygons and polyhedra. On 1 April 2016 at 20:45, Carsten Arnholm <[hidden email]> wrote: On 01. april 2016 21:11, Ronaldo wrote: _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org 
This post was updated on .
In reply to this post by macdarren
I generally use $fn=100; as the first line in my projects, setting it at a global level. With hull(), it then gives a nice, round shape. The minkowski version also gives a goodlooking result but when I subtract them from one anoter by using:
They are both overlapping exactly, after I fixed a few errors. Not sure which is better, though. Both hull and minkowski do a good job. Which would have the best performance anyways?
With kind regards,
Wim, W.A. ten Brink 
Oops, one minus needs to be a +. :)
 With kind regards, Wim, W.A. ten Brink  View this message in context: http://forum.openscad.org/Newbiewithrotationproblemtp16873p16904.html Sent from the OpenSCAD mailing list archive at Nabble.com. _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
With kind regards,
Wim, W.A. ten Brink 
In reply to this post by nophead
This is a quiz :) The following image is the preview of translated primitives. No boolean operations, no rotation, neither scale nor mirror. How to get them? 
It would appear that a good part of the answer to your question lies here:
https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Primitive_Solids Some of the answer involves low values of $fn along with cylinders of different r1 and r2 values. Do you already know the answers and this is a true quiz, or are you seeking a solution? 
In reply to this post by Ronaldo
The second from the left is a sphere. All the rest could be done using cylinder. The middle could be a cube. The second from right could be a sphere. See how OpenSCAD has warped me? When I first started using OpenSCAD, I was really annoyed by all of this. I wanted sphere to always produce a sphere, cylinder to always produce a cylinder, etc. I am still in favour of adding prism(), pyramid() and cone(), even though you would normally do those using cylinder(). On 2 April 2016 at 14:21, Ronaldo <[hidden email]> wrote: nophead wrote _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org 
On Sat, Apr 02, 2016 at 02:57:39PM 0400, doug moen wrote:
> See how OpenSCAD has warped me? When I first started using OpenSCAD, I was > really annoyed by all of this. I wanted sphere to always produce a sphere, > cylinder to always produce a cylinder, etc. IMHO, it is fine if openscad has to "simplify" cylinders to extruded polygons. However, in writing code, it would be best to assume that the implementation reserves the right to use the simplification OR BETTER. That means that the triangular prism could suddenly upgrade to a perfect cylinder if say the output format directly supports cylinders. But alas, it has become customary to exploit the defects of the implementation so that now there is no way back. > I am still in favour of adding prism(), pyramid() and cone(), even though > you would normally do those using cylinder(). Those would, be oneliner modules, right? There is a "system" library now, so it could be added there, right? Roger.  ** [hidden email] ** http://www.BitWizard.nl/ ** +31152600998 ** ** Delftechpark 26 2628 XH Delft, The Netherlands. KVK: 27239233 ** * BitWizard writes Linux device drivers for any device you may have! * The plan was simple, like my brotherinlaw Phil. But unlike Phil, this plan just might work. _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org 
In reply to this post by fred_dot_u
You are right. I generated the image so it is really a quiz. 
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