Hi Neon22, Very nice Python script, far superior to my hacked together MS Word VB macro! One issue I noticed while testing it is that OpenSCAD appears to list the facet vertices in anti-clockwise order (looking from outside) in its AMF export files, but polyhedron() likes the facets in clockwise order...? (My macro has the same issue.) -Trygon -- View this message in context: http://forum.openscad.org/Wrapping-text-around-a-complex-geometry-tp18145p18180.html Sent from the OpenSCAD mailing list archive at Nabble.com.

Trygon, I felt no offense neither had the intention to offend. Besides, it was not my approach but an usual one. To tell you the truth, I don't like it. The imperfections will be tiny if you discretize the strip a lot, but they are there anyway. And the render times grow drastically. Alex, A different approach avoids to break the text in pieces to adjust it to the surface. Instead, it breaks the string in characters. Since the Moebius strip is almost plane on the footprint of one character, it would be preferable to print each character at a time adjusting its position and orientation to the surface. This seems to be the approach of text_on.scad <https://github.com/brodykenrick/text_on_OpenSCAD> . The code is a lot complex and I confirm it running examples. For inprinting, it is virtually imperceptible. <http://forum.openscad.org/file/n18181/text_on_sphere.png> Despite the small radius of the sphere, it is hardly seen the inprint bottom is plane. The hard issue of this the approach is to deal with character spacing. The code of text_on.scad seems to choose mono-spacing. -- View this message in context: http://forum.openscad.org/Wrapping-text-around-a-complex-geometry-tp18145p18181.html Sent from the OpenSCAD mailing list archive at Nabble.com.

@Trygon - thanks very much for catching that. I added an option to invert faces - default to true. Looks better now. https://github.com/Neon22/amf-to-openscad-polyhedron -- View this message in context: http://forum.openscad.org/Wrapping-text-around-a-complex-geometry-tp18145p18182.html Sent from the OpenSCAD mailing list archive at Nabble.com.

Hi Alex, Some more ideas for you... 1) Make a flat strip with the required writing engraved into both sides: /l=170; w=10; d=2; // strip size s=6; // text size difference(){ translate([l/2,0,0]) cube([l,w,d],center=true); translate([0,0,0.5]) linear_extrude(height=1) text("If music be the food of love, play on. So full of",size=s,valign="center"); rotate([180,0,0]) translate([0,0,0.5]) linear_extrude(height=1) text("shapes is fancy that it alone is high fantastical.",size=s,valign="center"); } / <http://forum.openscad.org/file/n18183/FlatStrip1.png> <http://forum.openscad.org/file/n18183/FlatStrip2.png> Export and reimport as an OpenSCAD script - see Neon22's excellent Python script above. Using a non-affine transformation twist the strip 180 degrees along its axis (i.e. along the x-axis): <http://forum.openscad.org/file/n18183/TwistedStrip.png> Then using a second non-affine transformation roll the twisted strip around a circle on the x-z plane centred on the origin: <http://forum.openscad.org/file/n18183/MobiusBand.png> The script I used for both transformations combined is: /include<FlatStrip_convert.scad>; l=170; w=10; d=2; // strip size eps=0.001; l2=l+2*eps; // +2*eps => avoid self intersecting polyhedron r1=l2/(2*PI); points2=[ for(i=points) let( a1=360*(i[0]+eps)/l2, a2=a1/2, rm1=[cos(a1),-sin(a1)], rm2=[[cos(a2),-sin(a2)],[sin(a2),cos(a2)]], p1=[i[1],i[2]]*rm2+[0,r1], p2=p1[1]*rm1 ) [p2[0],p1[0],p2[1]] ]; union(){ polyhedron(points2,triangles,convexity=10); translate([r1,0,0]) cube([d,w,4*eps],center=true); // join strip } / This method is the same way you could go about making a mobius band out of a strip of paper. Cheers, Trygon -- View this message in context: http://forum.openscad.org/Wrapping-text-around-a-complex-geometry-tp18145p18183.html Sent from the OpenSCAD mailing list archive at Nabble.com.

Nice solution. I would expect a refined discretization of the imported polyhedron before the transformations. 2016-08-20 10:55 GMT-03:00 Trygon <db5765@outlook.com>: > Hi Alex, > > Some more ideas for you... > > 1) Make a flat strip with the required writing engraved into both sides: > > /l=170; w=10; d=2; // strip size > s=6; // text size > > difference(){ > translate([l/2,0,0]) cube([l,w,d],center=true); > translate([0,0,0.5]) linear_extrude(height=1) > text("If music be the food of love, play on. So full > of",size=s,valign="center"); > rotate([180,0,0]) translate([0,0,0.5]) linear_extrude(height=1) > text("shapes is fancy that it alone is high > fantastical.",size=s,valign="center"); > } > / > > <http://forum.openscad.org/file/n18183/FlatStrip1.png> > > <http://forum.openscad.org/file/n18183/FlatStrip2.png> > > Export and reimport as an OpenSCAD script - see Neon22's excellent Python > script above. > > Using a non-affine transformation twist the strip 180 degrees along its > axis > (i.e. along the x-axis): > > <http://forum.openscad.org/file/n18183/TwistedStrip.png> > > Then using a second non-affine transformation roll the twisted strip around > a circle on the x-z plane centred on the origin: > > <http://forum.openscad.org/file/n18183/MobiusBand.png> > > The script I used for both transformations combined is: > > /include<FlatStrip_convert.scad>; > > l=170; w=10; d=2; // strip size > eps=0.001; > l2=l+2*eps; // +2*eps => avoid self intersecting polyhedron > r1=l2/(2*PI); > > points2=[ for(i=points) let( a1=360*(i[0]+eps)/l2, > a2=a1/2, > rm1=[cos(a1),-sin(a1)], > rm2=[[cos(a2),-sin(a2)],[sin(a2),cos(a2)]], > p1=[i[1],i[2]]*rm2+[0,r1], > p2=p1[1]*rm1 ) > [p2[0],p1[0],p2[1]] ]; > > union(){ > polyhedron(points2,triangles,convexity=10); > translate([r1,0,0]) cube([d,w,4*eps],center=true); // join strip > } > / > > This method is the same way you could go about making a mobius band out of > a > strip of paper. > > Cheers, > Trygon > > > > > -- > View this message in context: http://forum.openscad.org/ > Wrapping-text-around-a-complex-geometry-tp18145p18183.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 >

You people are great, these discussions always leave me feeling very stupid, but smiling. Hopefully the algorithms you are hashing out can be imported to standard OpenSCAD someday. I too would like to map text to something other than a flat surface. But now I realize that it wasn't my tensor math that wasn't good enough, but my coding as well. Well done, all. On Sat, Aug 20, 2016 at 12:53 PM, Ronaldo Persiano <rcmpersiano@gmail.com> wrote: > Nice solution. I would expect a refined discretization of the imported > polyhedron before the transformations. > > 2016-08-20 10:55 GMT-03:00 Trygon <db5765@outlook.com>: > >> Hi Alex, >> >> Some more ideas for you... >> >> 1) Make a flat strip with the required writing engraved into both sides: >> >> /l=170; w=10; d=2; // strip size >> s=6; // text size >> >> difference(){ >> translate([l/2,0,0]) cube([l,w,d],center=true); >> translate([0,0,0.5]) linear_extrude(height=1) >> text("If music be the food of love, play on. So full >> of",size=s,valign="center"); >> rotate([180,0,0]) translate([0,0,0.5]) linear_extrude(height=1) >> text("shapes is fancy that it alone is high >> fantastical.",size=s,valign="center"); >> } >> / >> >> <http://forum.openscad.org/file/n18183/FlatStrip1.png> >> >> <http://forum.openscad.org/file/n18183/FlatStrip2.png> >> >> Export and reimport as an OpenSCAD script - see Neon22's excellent Python >> script above. >> >> Using a non-affine transformation twist the strip 180 degrees along its >> axis >> (i.e. along the x-axis): >> >> <http://forum.openscad.org/file/n18183/TwistedStrip.png> >> >> Then using a second non-affine transformation roll the twisted strip >> around >> a circle on the x-z plane centred on the origin: >> >> <http://forum.openscad.org/file/n18183/MobiusBand.png> >> >> The script I used for both transformations combined is: >> >> /include<FlatStrip_convert.scad>; >> >> l=170; w=10; d=2; // strip size >> eps=0.001; >> l2=l+2*eps; // +2*eps => avoid self intersecting polyhedron >> r1=l2/(2*PI); >> >> points2=[ for(i=points) let( a1=360*(i[0]+eps)/l2, >> a2=a1/2, >> rm1=[cos(a1),-sin(a1)], >> rm2=[[cos(a2),-sin(a2)],[sin(a2),cos(a2)]], >> p1=[i[1],i[2]]*rm2+[0,r1], >> p2=p1[1]*rm1 ) >> [p2[0],p1[0],p2[1]] ]; >> >> union(){ >> polyhedron(points2,triangles,convexity=10); >> translate([r1,0,0]) cube([d,w,4*eps],center=true); // join strip >> } >> / >> >> This method is the same way you could go about making a mobius band out >> of a >> strip of paper. >> >> Cheers, >> Trygon >> >> >> >> >> -- >> View this message in context: http://forum.openscad.org/Wrap >> ping-text-around-a-complex-geometry-tp18145p18183.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 > >