I was just looking at this problem myself. My starting point was http://www.thingiverse.com/thing:1481 <http://www.thingiverse.com/thing:1481> which wraps 3 copies of an image around a cylinder, then extrudes. There's about 15KB of Python source that generates an OpenSCAD file. License on this is "Creative Commons - Attribution - Non-Commercial". The author is Philipp Tiefenbacher (wizard23). I've refactored his code a little, and extended it to include conic surfaces, without really understanding how the underlying stuff works.I haven't finished my tidy-up yet, but I'm happy to share (now or when finished) as per Philipp's license. I'm new to openSCAD & Python (but a long-time programmer) so my "tidy" may be less than your "tidy". I'm equally happy for someone else to finish this off.If all you're interested in is mapping text characters to a cylinder, then http://www.thingiverse.com/thing:1661993 is useful.Frank -- View this message in context: http://forum.openscad.org/Images-on-curved-cylindrical-surface-tp17823p17904.html Sent from the OpenSCAD mailing list archive at Nabble.com.

Turned out to be easier than I thought... because openSCAD now can handle faces with more that 3 vertices, I could throw out all Philipp's stuff that I didn't understand. Here's working version: #!/usr/bin/python import sys import png import urllib from math import * from pyopenscad import * # Wrap a 2D image around a conic surface # Based on source code by Philipp Tiefenbacher (wizard23) # Licensed as per http://creativecommons.org/licenses/by-nc/3.0/ (Creative Commons - Attribution - Non-Commercial) # # Frank van der Hulst # 11 July 2016 # Usage: python conewrap.py imgFile bottomRadius topRadius > output.scad # Global variables numRows = 0 numCols = 0 minRadius = 0 # Read a grey-scale PNG and return a table (array of arrays) of pixel values def getPNG(filename): r=png.Reader(file=urllib.urlopen(filename)) data = r.read() pixel = data[2] raw = [] for row in pixel: r = [] raw.append(r) for px in row: r.append(px) return raw # Project a pixel from the bitmap onto a conic surface # Each pixel represents a unit square # The height describes the horizontal distance of that pixel from the surface of the cone. Where the cone is reasonably steep, this approximates to how high # the image is embossed on the cone's surface (positive z values), or how deeply it is recessed into the surface (negative z values) # bottomRadius and topRadius are the radii of the circles at the bottom and top of the conic fragment. They may be equal for a cylinder, or topRadius may be larger or smaller than bottomRadius. # topRadius may be zero to produce an actual cone. If bottomRadius < the minimum radius to map the image (e.g. the image is 256 pixels wide && bottomRadius < 40.74 (256/2*pi)), bottomRadius is increased # cylRange is the fraction (0-1) of the cylinder the image should be wrapped around (e.g. 0.25 means wrapi it around 90 degrees) def projectCone(x, y, height, bottomRadius, topRadius, cylRange): # Calculate radial for wrapping a = x*2*pi/numCols*cylRange # Calculate distance from axis... linear interpolation between top and bottom radius of the cone r = topRadius + (bottomRadius-topRadius) * (numRows-y)*1.0/numRows + height # Calculate 3D coordinate of this point return [r*cos(a), r*sin(a), y] # Map the pixMap onto a conic surface with the given radii def mapImage(pixMap, bottomRadius, topRadius): minRadius=numCols/(2*pi) if (bottomRadius < minRadius): bottomRadius = minRadius cylRange = minRadius*1.0/bottomRadius # Generate all the points for the surface pts = [] for y in xrange(0, numRows): # Generate a "circle" of points for this layer for x in xrange(0, numCols): # Pixels range in value from 0-255, where 0 = black and 255 = white p = projectCone(x, y, -pixMap[y][x]/255.0, bottomRadius, topRadius, cylRange) pts.append(p) # Generate bottom face: A face is 4 indices of points faces = [] bottom=[] for x in xrange(0, numCols): bottom.append(x) bottom.append(0) faces.append(bottom) # Generate all the faces: A face is 4 indices of points for y in range(0, numRows-1): for x in range(0, numCols): p1 = y*numCols+(x+1)%numCols p2 = y*numCols+x p3 = (y+1)*numCols+x p4 = (y+1)*numCols + (x+1)%numCols f = [p1, p2, p3, p4] faces.append(f) # Generate top face if this not a complete cone... NB reverse direction if (topRadius != 0): top=[] for x in xrange(0, numCols): top.append(numRows*numCols - x) top.append(numRows*numCols) faces.append(top) return polyhedron(pts, faces, 6) if (len(sys.argv) !=4): print "Usage: python ", sys.argv[0], "imgFile bottomRadius topRadius > output.scad" print "e.g. python ", sys.argv[0], "santa-claus-grey.png 45 0 > santa.scad" exit() # File to project must be 8-bit greyscale imgFile = sys.argv[1] # Radius of the bottom of the cone... if it is less than minRadius, the cone will be expanded to minRadius. If greater than minRadius, a D-shaped partial cone will be produced # Zero means the output cone's radius will be adjusted to wrap the image exactly once around the cone coneRadius = float(sys.argv[2]) # Radius of the top of the cone... may be zero topRadius = float(sys.argv[3]) # Read pixel map from PNG file pixMap = getPNG(imgFile) # Flip image upside-down pixMap.reverse() numCols = len(pixMap[0]) numRows = len(pixMap) result = mapImage(pixMap, coneRadius, topRadius) import time print time.strftime("// Generated: %Y-%m-%d %H:%M") print "// Source file: ", imgFile print "// Image Height = ", numRows print "// Image Width = ", numCols print "// Minimum cylinder radius = ", minRadius print "// Cylinder radius = ", coneRadius print "$fa=2; $fs=0.5;\n" print result.render() On Mon, Jul 11, 2016 at 12:54 PM, frankv <drifter.frank@gmail.com> wrote: > I was just looking at this problem myself. My starting point was http://www.thingiverse.com/thing:1481 > which wraps 3 copies of an image around a cylinder, then extrudes. There's > about 15KB of Python source that generates an OpenSCAD file. License on > this is "Creative Commons - Attribution - Non-Commercial". The author is > Philipp Tiefenbacher (wizard23). I've refactored his code a little, and > extended it to include conic surfaces, without really understanding how the > underlying stuff works. I haven't finished my tidy-up yet, but I'm happy to > share (now or when finished) as per Philipp's license. I'm new to openSCAD > & Python (but a long-time programmer) so my "tidy" may be less than your > "tidy". I'm equally happy for someone else to finish this off. If all > you're interested in is mapping text characters to a cylinder, then > http://www.thingiverse.com/thing:1661993 is useful. Frank > ------------------------------ > View this message in context: Re: Images on curved (cylindrical) surface > <http://forum.openscad.org/Images-on-curved-cylindrical-surface-tp17823p17904.html> > Sent from the OpenSCAD mailing list archive <http://forum.openscad.org/> > at Nabble.com. > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > >

When I need to wrap a shape around a cylinder, I cut it in small pieces that I reassemble on the cylinder. The shape (here in orange) can be anything close to flat. <http://forum.openscad.org/file/n17908/wrap2.wrap2> Here is the code: w=30; // radius of cylinder h=100; // height of cylinder // // the pattern should be at [w,0,0] and move in y according to a // pattern should be 2Pi * w size in Y // Some rings... // module pattern0(a=0) { for(i=[0:3]) { translate([w,a*PI/180*w+i*PI/2*w+w,-20]) rotate([-90,0,-90]) difference() { cylinder(d1=PI/2*w+3,d2=0,h=80); translate([0,0,-0.1]) cylinder(d1=PI/2*w-3,d2=45+50,h=80); } } } // some text... module pattern1(a=0) { translate([w,a*PI/180*w,10]) rotate([90,0,90]) linear_extrude(height=5,convexity=2) text("bonjour!",32); } // rings and text... module pattern2(a=0) { pattern0(a); pattern1(a); } module cutter(a=5,w=50,h=100) { render() intersection() { rotate([0,0,-a/2]) translate([0,0,-h/2]) cube([w,50,h]); rotate([0,0,a/2]) translate([0,-50,-h/2]) cube([w,50,h]); } } %cylinder(r=w,h=h,center=true); color("orange") translate([0,0,0]) pattern2(0); step=5; for( i=[0:step:360+2*step] ) { rotate([0,0,i]) intersection() { pattern2(-i); cutter(step,w+20,h+20); } } -- View this message in context: http://forum.openscad.org/Images-on-curved-cylindrical-surface-tp17823p17908.html Sent from the OpenSCAD mailing list archive at Nabble.com.

Would there be a way to package this in such a way that one could use it with the Thingiverse customizer? -- View this message in context: http://forum.openscad.org/Images-on-curved-cylindrical-surface-tp17823p18331.html Sent from the OpenSCAD mailing list archive at Nabble.com.

you can't wrap the python for custoizer but if you embed the scad code into your single file. no problem. Customiser can't include or use any external file except for the ones the website includes itself. over which you have no control. -- View this message in context: http://forum.openscad.org/Images-on-curved-cylindrical-surface-tp17823p18332.html Sent from the OpenSCAD mailing list archive at Nabble.com.