Hoping someone can give me a hand here: I've got a PNG that I want to "stamp" into the side of an object. To test this, I created the following code: *** BEGIN CODE *** logo="M3logo1.png"; wid=58; logox = 587; logoy = 623; difference(){ cube([wid,wid,2]); translate([wid/4,wid/4,3]) scale([.5*wid/logox,.5*wid/logoy,.02]) surface(file=logo,invert=true); } *** END CODE *** As shown below, it previews (F5) correctly. However, the GUI is very sluggish with this render. When I attempt to render (F6), however, I get nothing: The original PNG: <http://forum.openscad.org/file/n12517/M3logo1.png> The Preview: <http://forum.openscad.org/file/n12517/Screen_Shot_2015-04-29_at_11.png> The Attempt to Render: <http://forum.openscad.org/file/n12517/Screen_Shot_2015-04-29_at_11.png> One other data point: I've increased my caches in the GUI, but when I run "OpenSCAD -o foo.stl LogoTest.scad" from the command line, I get "WARNING: GeometryEvaluator: Node didn't fit into cache" errors (three of them), the process runs forever (as far as I can tell) and uses 99ish% of the CPU. Any help that anyone can provide would be greatly appreciated. Thanks a lot! Mike Lewis -- View this message in context: http://forum.openscad.org/Surface-from-PNG-and-difference-tp12517.html Sent from the OpenSCAD mailing list archive at Nabble.com.

Your .png is quiet big. A resolution of 587 * 623 is a lot. Try to figure out how many triangles this surface would have: 731 402. This will bring Openscad to its knees. I havent checked the manual, but I seem to remember that there is a limit of 100*100 for the surface command. Hope it helps. P.S.: the 2 screen shots dont display 2015-04-29 19:01 GMT+02:00 MLewis <revmikelewis@gmail.com>: > Hoping someone can give me a hand here: > > I've got a PNG that I want to "stamp" into the side of an object. To test > this, I created the following code: > > *** BEGIN CODE *** > logo="M3logo1.png"; > > wid=58; > logox = 587; > logoy = 623; > > difference(){ > cube([wid,wid,2]); > translate([wid/4,wid/4,3]) > scale([.5*wid/logox,.5*wid/logoy,.02]) > surface(file=logo,invert=true); > > } > *** END CODE *** > > As shown below, it previews (F5) correctly. However, the GUI is very > sluggish with this render. > When I attempt to render (F6), however, I get nothing: > > The original PNG: > <http://forum.openscad.org/file/n12517/M3logo1.png> > > The Preview: > <http://forum.openscad.org/file/n12517/Screen_Shot_2015-04-29_at_11.png> > > The Attempt to Render: > <http://forum.openscad.org/file/n12517/Screen_Shot_2015-04-29_at_11.png> > > One other data point: I've increased my caches in the GUI, but when I run > "OpenSCAD -o foo.stl LogoTest.scad" from the command line, I get "WARNING: > GeometryEvaluator: Node didn't fit into cache" errors (three of them), the > process runs forever (as far as I can tell) and uses 99ish% of the CPU. > > Any help that anyone can provide would be greatly appreciated. Thanks a > lot! > > > Mike Lewis > > > > -- > View this message in context: > http://forum.openscad.org/Surface-from-PNG-and-difference-tp12517.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 > -- stempeldergeschichte@googlemail.com <karsten@rohrbach.de> P.S. Falls meine E-Mail kürzer ausfällt als Dir angenehm ist: Ich probiere gerade aus kurze Antworten statt gar keine Antworten zu schreiben. Wenn Du gerne mehr lesen möchtest, dann lass es mich bitte wissen. P.S. In case my e-mail is shorter than you enjoy: I am currently trying short replies instead of no replies at all. Please let me know, if you like to read more. Enjoy!

On 04/29/2015 07:01 PM, MLewis wrote: > I've got a PNG that I want to "stamp" into the side of an object. To test > this, I created the following code: > Try scaling down the image a bit. The way surface() creates the object is not ideal for this type of usage as it creates a huge number of vertices making the difference very slow. The option to import images as 2D shape will hopefully come soon, that would probably make things quite a bit faster, e.g. (https://github.com/openscad/openscad/pull/1110). To get a similar result it would be possible to convert the image to DXF using inkscape. With size 200x212 the model renders in 48 seconds on my notebook. ciao, Torsten.

On 04/29/2015 01:01 PM, MLewis wrote: > logox = 587; > logoy = 623; There's the problem: too many pixels. In round numbers, anything over about 300x300 pixels produces too many polygons / faces, causing OpenSCAD to grind to a halt while chewing up all available memory & swap space in a vain attempt to perform CSG. Scaling the PNG image by 1/8 = 75x81 ran for 9 s and by 1/4 = 150x163 ran for 40 s. With more patience, 300x326 would eventually finish. The PNG is transparent and the logo ran right up to the edges. I laid it over a white background and added a thin white border, which eliminated the "degenerate polygon" complaints. The "invert=true" option produces nasty undercuts on the reduced-resolution images, because the grayscale works the wrong way. I think you'll get better results with a white logo on a black background, regardless of the resolution. I found much of that out the hard way while making 3D printed cookie presses: http://softsolder.com/2012/11/28/automated-cookie-cutters-fine-tuning/ Gritty resolution sufficed for those... -- Ed softsolder.com