Easy lithopanes with Simplify3D

[jimc]

s3d definitely has issues with large models. i start having issues at about the 1.5mil polygon area. i have tried a few large models in the past, one 2mil, a couple around 1.5mil and some around 1.2mil. the 2 and 1.5 all crashed but i did ok at the 1.2 area.

on another not i thought i would post up these pics to show the same litho viewed from both sides. you can see one side it looks alot more crisp and detailed.

IMG_2892.jpg (61.76 KiB) Viewed 10999 times

IMG_2895.jpg (44.29 KiB) Viewed 10999 times

[Tim]

And here we go. . . Thingiverse thing #326214, the "World Cup" cylindrical lithomap!
Source code included!

[jsc]

When I request a 180 degree cup, I get half a cylinder. Is there any way to get a full cylinder, but only stretch across the requested angle?

My OpenSCAD version lets you set the height, and adjusts the diameter to maintain the aspect ratio (assuming 180 degree coverage); perhaps you might consider supporting an option like that. I'm not sure what it's doing, but it appears to give me the same cylinder height no matter what degree coverage I request.

Not a big deal, but it would be nice to present the STL in printing position instead of lying down.

In order to compile on a Mac, I had to remove malloc.h, and to get rid of warnings, include string.h, stdlib.h, and change (char *) to (unsigned char *) in the malloc for idata near line 300.

Nice job, super fast.

[Tim]

Options are a little limited when I only spent a day writing the code!

Yes, I was also thinking of including an option that would allow the image to cover part of an arc and pad out the rest as a blank cylinder. A similar option to add a blank border around the flat lithophane might be nice, too.

I will eventually get around to correcting the axes and presenting the cylinder in the natural orientation for printing. Also to make sure that the "xflip" option will switch the image to the outside of the cylinder.

Thanks for the bug report on compile options, too. I may have some time to work on the code more today, and get out an improved version.

[jsc]

I found it necessary to let the user specify whether their background (uninverted) was mainly dark or light, to pad out the rest as thick or thin. You should be able to specify the padding thickness, or maybe even auto-compute a good one as an average of the border pixels.

[jimc]

ok here are some pics of the light boxes i whipped up. had to get these done so the kids could give them out for mothers day. i made 4 of them. i threw together the boxes and put a finish on them, painted the inside white. the back panel is printed in abs then painted white on the inside and a matching brown on the outside. the leds are made for backlighting signs, channel letters etc. i have used these on a ton of projects in the past. they are waterproof and dont dim out over alot of hours of use. i originally had 2 of them in each light box but it was way too bright. one is just right.

IMG_2901.jpg (56.06 KiB) Viewed 10976 times

IMG_2900.jpg (54.96 KiB) Viewed 10976 times

IMG_2898.jpg (67.33 KiB) Viewed 10976 times

IMG_2899.jpg (70.21 KiB) Viewed 10976 times

[jsc]

Did you have boxes that fit already, or did you make those?

[Tim]

The boxes are really nice, Jim. You always do a great job. . .

And Jin---Your wish list has been fulfilled. I just posted a new version of the C code on Thingiverse. The cylinder orientation is correct to stand on the XY plane surface, and I added an option to extend the cylinder beyond the image.

There is definitely something wrong with the scaling. I have to go back through my equations and figure out exactly what. At any rate, do "lithocup --help" to get a list of options. There's a "yscale" that changes the Y scaling relative to everything else. So I was doing:

Code: Select all

    lithocup -y1.8 -f2 -a360 cylindrical_equal2.ppm world_cup_2.stl

to get the final cylinder, and I should have noticed that although my original map was a bit squashed, there was no way that it needed scaling by 1.8 to get to a normal looking scale close to the equator. For now, you can mess with the "--yscale" or "-y" setting, and I'll figure out the correct equation and post the corrected version.

To answer some of your other questions: The "--pad" setting is the minimum thickness of the cylinder, and the "--thick" setting is the maximum thickness. Both in millimeters. I used 0.5mm for the default minimum and 3mm for the default maximum.

[jimc]

no jin i made the boxes. it helps to have a full wood shop here at the house and thanks tim.

[Tim]

Jim---Do you have a part number/supplier for those LEDs?