Simply cut and paste it from the email. There is no line 38, so I think you cut one too many lines. On 24 December 2015 at 12:57, Kenneth Sloan <kennethrsloan@gmail.com> wrote: > Looks nice. So…I tried to copy it to play with it (and understand it). > > I get: > > ERROR: Parser error in line 38: syntax error > ERROR: Conmpilation failed! > > Presumably, that’s because I’m behind on my updates. > What version do I need, please? > > -- > Kenneth Sloan > KennethRSloan@gmail.com > Vision is the art of seeing what is invisible to others. > > > > > On Dec 24, 2015, at 04:01 , nop head <nop.head@gmail.com> wrote: > > Here is a version that finally works. > > <hyperbola.png> > ​ > xmin = -1; > xmax = 1; > ymin = -1; > ymax = 1; > step = 0.05; > zmin = min(xmin *ymax, xmax * ymin); > > xpoints = floor((xmax - xmin) / step) + 1; > ypoints = floor((ymax - ymin) / step) + 1; > function index(x,y) = x * ypoints + y + 2; > function x(i) = xmin + i * step; > function y(i) = ymin + i * step; > > points = concat([[xmin, ymin, zmin]], > [[xmax, ymax, zmin]], > [for(i = [0 : xpoints - 1]) for(j = [0 : ypoints - 1]) [x(i), > y(j), x(i) * y(j)]]); > > function flatten(l) = [for(a = l) for (b = a) b]; > > base = concat( > [[1, 0, index(xpoints - 1, 0)]], > [[0, 1, index(0, ypoints - 1)]], > [for(i = [0 : xpoints - 2]) [0, index(i, 0), index(i + 1, 0)]], > [for(j = [0 : ypoints - 2]) [0, index(0, j + 1), index(0, j)]], > [for(i = [0 : xpoints - 2]) [1, index(i + 1, ypoints - 1), > index(i, ypoints - 1)]], > [for(j = [0 : ypoints - 2]) [1, index(xpoints - 1, j), > index(xpoints - 1, j + 1)]] > ); > > faces = flatten([for(i = [0 : xpoints - 2]) for(j = [0 : ypoints - 2]) > [[index(i,j), index(i, j + 1), index(i + 1, j + 1)], > [index(i + 1, j + 1), index(i + 1, j ), index(i, j)]] > ]); > > difference() { > sphere(r= 0.5, $fn=80); > polyhedron(points, concat(base, faces), convexity = 2); > } > ​ > > My stupid mistake was flattening the base list when it didn't need to be. > The result was some faces with multiple triangles instead of single > triangle per face. Looks like cgal can't handle that but the rest of the > system can. The STL file it exported was correct.. > > On 24 December 2015 at 07:45, Mekko <serve@perdix.org> wrote: > >> LOL. Actually, I'm not the potato chip guy - I'm just trying to cut a >> sphere >> in half with an hyperbola and getting a potato chip instead. >> >> Hopefully the true Potato Chip Guy is reading this thread though! >> >> >> >> -- >> View this message in context: >> http://forum.openscad.org/intersecting-with-an-hyperbola-tp15280p15313.html >> Sent from the OpenSCAD mailing list archive at Nabble.com. >> >> _______________________________________________ >> OpenSCAD mailing list >> Discuss@lists.openscad.org >> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >> > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > > > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > >

Here is a slightly simpler version without the use of flatten plus a few comments: - xmin = -1; xmax = 1; ymin = -1; ymax = 1; step = 0.05; zmin = min(xmin * ymax, xmax * ymin); xpoints = floor((xmax - xmin) / step) + 1; ypoints = floor((ymax - ymin) / step) + 1; function index(x,y) = x * ypoints + y + 2; // plus 2 because of two extra points added to make the base function x(i) = xmin + i * step; function y(i) = ymin + i * step; points = concat([[xmin, ymin, zmin]], // two extra points to allow a rectangular base [[xmax, ymax, zmin]], [for(i = [0 : xpoints - 1], j = [0 : ypoints - 1]) [x(i), y(j), x(i) * y(j)]]); base = concat( [[1, 0, index(xpoints - 1, 0)]], // two triangles to make the base [[0, 1, index(0, ypoints - 1)]], // four triangule fans for the sides [for(i = [0 : xpoints - 2]) [0, index(i, 0), index(i + 1, 0)]], [for(i = [0 : xpoints - 2]) [1, index(i + 1, ypoints - 1), index(i, ypoints - 1)]], [for(j = [0 : ypoints - 2]) [0, index(0, j + 1), index(0, j)]], [for(j = [0 : ypoints - 2]) [1, index(xpoints - 1, j), index(xpoints - 1, j + 1)]] ); faces = concat( // connect every four points with two triangles [for(i = [0 : xpoints - 2], j = [0 : ypoints - 2]) [index(i,j), index(i, j + 1), index(i + 1, j + 1)]], [for(i = [0 : xpoints - 2], j = [0 : ypoints - 2]) [index(i + 1, j + 1), index(i + 1, j ), index(i, j)]] ); difference() { sphere(r= 0.5, $fn=80); polyhedron(points, concat(base, faces), convexity = 2); } On 24 December 2015 at 13:51, nop head <nop.head@gmail.com> wrote: > Simply cut and paste it from the email. There is no line 38, so I think > you cut one too many lines. > > On 24 December 2015 at 12:57, Kenneth Sloan <kennethrsloan@gmail.com> > wrote: > >> Looks nice. So…I tried to copy it to play with it (and understand it). >> >> I get: >> >> ERROR: Parser error in line 38: syntax error >> ERROR: Conmpilation failed! >> >> Presumably, that’s because I’m behind on my updates. >> What version do I need, please? >> >> -- >> Kenneth Sloan >> KennethRSloan@gmail.com >> Vision is the art of seeing what is invisible to others. >> >> >> >> >> On Dec 24, 2015, at 04:01 , nop head <nop.head@gmail.com> wrote: >> >> Here is a version that finally works. >> >> <hyperbola.png> >> ​ >> xmin = -1; >> xmax = 1; >> ymin = -1; >> ymax = 1; >> step = 0.05; >> zmin = min(xmin *ymax, xmax * ymin); >> >> xpoints = floor((xmax - xmin) / step) + 1; >> ypoints = floor((ymax - ymin) / step) + 1; >> function index(x,y) = x * ypoints + y + 2; >> function x(i) = xmin + i * step; >> function y(i) = ymin + i * step; >> >> points = concat([[xmin, ymin, zmin]], >> [[xmax, ymax, zmin]], >> [for(i = [0 : xpoints - 1]) for(j = [0 : ypoints - 1]) [x(i), >> y(j), x(i) * y(j)]]); >> >> function flatten(l) = [for(a = l) for (b = a) b]; >> >> base = concat( >> [[1, 0, index(xpoints - 1, 0)]], >> [[0, 1, index(0, ypoints - 1)]], >> [for(i = [0 : xpoints - 2]) [0, index(i, 0), index(i + 1, 0)]], >> [for(j = [0 : ypoints - 2]) [0, index(0, j + 1), index(0, j)]], >> [for(i = [0 : xpoints - 2]) [1, index(i + 1, ypoints - 1), >> index(i, ypoints - 1)]], >> [for(j = [0 : ypoints - 2]) [1, index(xpoints - 1, j), >> index(xpoints - 1, j + 1)]] >> ); >> >> faces = flatten([for(i = [0 : xpoints - 2]) for(j = [0 : ypoints - 2]) >> [[index(i,j), index(i, j + 1), index(i + 1, j + 1)], >> [index(i + 1, j + 1), index(i + 1, j ), index(i, j)]] >> ]); >> >> difference() { >> sphere(r= 0.5, $fn=80); >> polyhedron(points, concat(base, faces), convexity = 2); >> } >> ​ >> >> My stupid mistake was flattening the base list when it didn't need to be. >> The result was some faces with multiple triangles instead of single >> triangle per face. Looks like cgal can't handle that but the rest of the >> system can. The STL file it exported was correct.. >> >> On 24 December 2015 at 07:45, Mekko <serve@perdix.org> wrote: >> >>> LOL. Actually, I'm not the potato chip guy - I'm just trying to cut a >>> sphere >>> in half with an hyperbola and getting a potato chip instead. >>> >>> Hopefully the true Potato Chip Guy is reading this thread though! >>> >>> >>> >>> -- >>> View this message in context: >>> http://forum.openscad.org/intersecting-with-an-hyperbola-tp15280p15313.html >>> Sent from the OpenSCAD mailing list archive at Nabble.com. >>> >>> _______________________________________________ >>> OpenSCAD mailing list >>> Discuss@lists.openscad.org >>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >>> >> >> _______________________________________________ >> OpenSCAD mailing list >> Discuss@lists.openscad.org >> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >> >> >> >> _______________________________________________ >> OpenSCAD mailing list >> Discuss@lists.openscad.org >> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >> >> >

Thanks. There was <white-space> at the end. I removed it and all is well. So, now the question is: why is <white-space> a syntax error? Perhaps not an important question - but it is puzzling (to me). -- Kenneth Sloan KennethRSloan@gmail.com <mailto:KennethRSloan@gmail.com> Vision is the art of seeing what is invisible to others. > On Dec 24, 2015, at 07:51 , nop head <nop.head@gmail.com> wrote: > > Simply cut and paste it from the email. There is no line 38, so I think you cut one too many lines. > > On 24 December 2015 at 12:57, Kenneth Sloan <kennethrsloan@gmail.com <mailto:kennethrsloan@gmail.com>> wrote: > Looks nice. So…I tried to copy it to play with it (and understand it). > > I get: > > ERROR: Parser error in line 38: syntax error > ERROR: Conmpilation failed! > > Presumably, that’s because I’m behind on my updates. > What version do I need, please? > > -- > Kenneth Sloan > KennethRSloan@gmail.com <mailto:KennethRSloan@gmail.com> > Vision is the art of seeing what is invisible to others. > > > > >> On Dec 24, 2015, at 04:01 , nop head <nop.head@gmail.com <mailto:nop.head@gmail.com>> wrote: >> >> Here is a version that finally works. >> >> <hyperbola.png> >> ​ >> xmin = -1; >> xmax = 1; >> ymin = -1; >> ymax = 1; >> step = 0.05; >> zmin = min(xmin *ymax, xmax * ymin); >> >> xpoints = floor((xmax - xmin) / step) + 1; >> ypoints = floor((ymax - ymin) / step) + 1; >> function index(x,y) = x * ypoints + y + 2; >> function x(i) = xmin + i * step; >> function y(i) = ymin + i * step; >> >> points = concat([[xmin, ymin, zmin]], >> [[xmax, ymax, zmin]], >> [for(i = [0 : xpoints - 1]) for(j = [0 : ypoints - 1]) [x(i), y(j), x(i) * y(j)]]); >> >> function flatten(l) = [for(a = l) for (b = a) b]; >> >> base = concat( >> [[1, 0, index(xpoints - 1, 0)]], >> [[0, 1, index(0, ypoints - 1)]], >> [for(i = [0 : xpoints - 2]) [0, index(i, 0), index(i + 1, 0)]], >> [for(j = [0 : ypoints - 2]) [0, index(0, j + 1), index(0, j)]], >> [for(i = [0 : xpoints - 2]) [1, index(i + 1, ypoints - 1), index(i, ypoints - 1)]], >> [for(j = [0 : ypoints - 2]) [1, index(xpoints - 1, j), index(xpoints - 1, j + 1)]] >> ); >> >> faces = flatten([for(i = [0 : xpoints - 2]) for(j = [0 : ypoints - 2]) >> [[index(i,j), index(i, j + 1), index(i + 1, j + 1)], >> [index(i + 1, j + 1), index(i + 1, j ), index(i, j)]] >> ]); >> >> difference() { >> sphere(r= 0.5, $fn=80); >> polyhedron(points, concat(base, faces), convexity = 2); >> } >> ​ >> >> My stupid mistake was flattening the base list when it didn't need to be. The result was some faces with multiple triangles instead of single triangle per face. Looks like cgal can't handle that but the rest of the system can. The STL file it exported was correct.. >> >> On 24 December 2015 at 07:45, Mekko <serve@perdix.org <mailto:serve@perdix.org>> wrote: >> LOL. Actually, I'm not the potato chip guy - I'm just trying to cut a sphere >> in half with an hyperbola and getting a potato chip instead. >> >> Hopefully the true Potato Chip Guy is reading this thread though! >> >> >> >> -- >> View this message in context: http://forum.openscad.org/intersecting-with-an-hyperbola-tp15280p15313.html <http://forum.openscad.org/intersecting-with-an-hyperbola-tp15280p15313.html> >> Sent from the OpenSCAD mailing list archive at Nabble.com <http://nabble.com/>. >> >> _______________________________________________ >> OpenSCAD mailing list >> Discuss@lists.openscad.org <mailto:Discuss@lists.openscad.org> >> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org <http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org> >> >> _______________________________________________ >> OpenSCAD mailing list >> Discuss@lists.openscad.org <mailto:Discuss@lists.openscad.org> >> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org <http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org> > > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org <mailto:Discuss@lists.openscad.org> > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org <http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org> > > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

White space isn't a syntax error, perhaps it contained an invisible control character or something. On 24 December 2015 at 15:14, Kenneth Sloan <kennethrsloan@gmail.com> wrote: > Thanks. There was <white-space> at the end. I removed it and all is well. > > So, now the question is: why is <white-space> a syntax error? > > Perhaps not an important question - but it is puzzling (to me). > > > -- > Kenneth Sloan > KennethRSloan@gmail.com > Vision is the art of seeing what is invisible to others. > > > > > On Dec 24, 2015, at 07:51 , nop head <nop.head@gmail.com> wrote: > > Simply cut and paste it from the email. There is no line 38, so I think > you cut one too many lines. > > On 24 December 2015 at 12:57, Kenneth Sloan <kennethrsloan@gmail.com> > wrote: > >> Looks nice. So…I tried to copy it to play with it (and understand it). >> >> I get: >> >> ERROR: Parser error in line 38: syntax error >> ERROR: Conmpilation failed! >> >> Presumably, that’s because I’m behind on my updates. >> What version do I need, please? >> >> -- >> Kenneth Sloan >> KennethRSloan@gmail.com >> Vision is the art of seeing what is invisible to others. >> >> >> >> >> On Dec 24, 2015, at 04:01 , nop head <nop.head@gmail.com> wrote: >> >> Here is a version that finally works. >> >> <hyperbola.png> >> ​ >> xmin = -1; >> xmax = 1; >> ymin = -1; >> ymax = 1; >> step = 0.05; >> zmin = min(xmin *ymax, xmax * ymin); >> >> xpoints = floor((xmax - xmin) / step) + 1; >> ypoints = floor((ymax - ymin) / step) + 1; >> function index(x,y) = x * ypoints + y + 2; >> function x(i) = xmin + i * step; >> function y(i) = ymin + i * step; >> >> points = concat([[xmin, ymin, zmin]], >> [[xmax, ymax, zmin]], >> [for(i = [0 : xpoints - 1]) for(j = [0 : ypoints - 1]) [x(i), >> y(j), x(i) * y(j)]]); >> >> function flatten(l) = [for(a = l) for (b = a) b]; >> >> base = concat( >> [[1, 0, index(xpoints - 1, 0)]], >> [[0, 1, index(0, ypoints - 1)]], >> [for(i = [0 : xpoints - 2]) [0, index(i, 0), index(i + 1, 0)]], >> [for(j = [0 : ypoints - 2]) [0, index(0, j + 1), index(0, j)]], >> [for(i = [0 : xpoints - 2]) [1, index(i + 1, ypoints - 1), >> index(i, ypoints - 1)]], >> [for(j = [0 : ypoints - 2]) [1, index(xpoints - 1, j), >> index(xpoints - 1, j + 1)]] >> ); >> >> faces = flatten([for(i = [0 : xpoints - 2]) for(j = [0 : ypoints - 2]) >> [[index(i,j), index(i, j + 1), index(i + 1, j + 1)], >> [index(i + 1, j + 1), index(i + 1, j ), index(i, j)]] >> ]); >> >> difference() { >> sphere(r= 0.5, $fn=80); >> polyhedron(points, concat(base, faces), convexity = 2); >> } >> ​ >> >> My stupid mistake was flattening the base list when it didn't need to be. >> The result was some faces with multiple triangles instead of single >> triangle per face. Looks like cgal can't handle that but the rest of the >> system can. The STL file it exported was correct.. >> >> On 24 December 2015 at 07:45, Mekko <serve@perdix.org> wrote: >> >>> LOL. Actually, I'm not the potato chip guy - I'm just trying to cut a >>> sphere >>> in half with an hyperbola and getting a potato chip instead. >>> >>> Hopefully the true Potato Chip Guy is reading this thread though! >>> >>> >>> >>> -- >>> View this message in context: >>> http://forum.openscad.org/intersecting-with-an-hyperbola-tp15280p15313.html >>> Sent from the OpenSCAD mailing list archive at Nabble.com >>> <http://nabble.com/>. >>> >>> _______________________________________________ >>> OpenSCAD mailing list >>> Discuss@lists.openscad.org >>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >>> >> >> _______________________________________________ >> OpenSCAD mailing list >> Discuss@lists.openscad.org >> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >> >> >> >> _______________________________________________ >> OpenSCAD mailing list >> Discuss@lists.openscad.org >> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >> >> > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > > > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > >

nophead, this is beautiful - thanks! The comments are particularly helpful to me as I design more complex shapes that can't be composed from cylinder(), cube(), sphere(), etc. -- View this message in context: http://forum.openscad.org/intersecting-with-an-hyperbola-tp15280p15335.html Sent from the OpenSCAD mailing list archive at Nabble.com.