Some info and resources I stumbled across on Steve Mould’s discord channel and elsewhere while digging into this, including scratchhologram C# code that can load .x3d files, simulate and generate arcs on the view plane…
That’s the one i use. I couldn’t really find one cheaper that looked like it worked well. This one did a great job for me on the big acrylic sign i did.
Lots. Can tune number of points/arcs, GIF shows rough milling time estimates. Guaranteed to be slow. Waiting on diamond bit, sunk enough time into tuning/extending app to rationalize the cost.
Currently trying to figure out way to remove lines/edges on the same face, have an idea (don’t render edges shared by adjacent faces on the same plane, maybe…). My math isn’t great, and it’s been a while since I coded 3D geometry rendering… Fortunately Mike Miller did all the hard stuff already.
Coded up simple G2 circular arc based script for now. Haven’t looked into tweaking elliptical arcs to reduce distortion, haven’t verified/implemented occlusion. Will share fork if my edits seem more useful than harmful for someone else to use.
2023/2/22 Edit: Model is easier to discern by hiding edges between faces on the same plane. Less arcs, noise and mill time. Fancy drag bit arrived, testing on cheapo bits first…
2023/2/23 Edit: No physical testing yet. Still improving functionality/performance, e.g. arcs for hidden edges/points were mistakenly being drawn. Currently figuring out partial arc segments so occlusion works when changing view angle.
The things you’re doing with laser etching look like sorcery to me. We have a bunch of laser folks here too. Look forward to learning how you guys are lasering color finishes from their metal stock?
Not yet, but maybe, SVG should be very doable (have written code to generate that before), will take a look if I can figure out occlusion, and speed things up.
I reached out to Mike Miller via github to thank him for sharing the project, and let him know it’s being tinkered with here.
Will keep sharing occasional updates partly for anyone who’s interested, but also partly to help discover if others have done this already (so I don’t need to ), and/or discover interesting related work out there. Cheers!
Nice additions to the original program! I’d love to take a look at your fork, and use the gcode export to do some practical testing on a few different materials i’ve ordered, if you’re able to publish it.
I’m also trying to make some research with rhino7 grasshopper to generate geometry easy, but looks like it takes too long, so will be happy to see your examples and test them.
Figured out how to implement occlusion (renders partial arc segments instead of full 180degrees). Working on SVG export, performance and cleaning up (much hackery…) before pushing to my fork/repo.
Removing GCODE export for now, was personally OK with spitting out GCODE for personal consumption. However… I don’t want bugs/incorrect-usage to damage people’s machines and/or $$$ diamond bits.
Since we’re working with 3D models, I took the liberty of experimenting with V1 to symbolically represent V1 machines. The Nozzle is meh, was meant to look more V like, was quick 10 min Fusion 360 3D hack job, mainly just to be a proof of concept, hope it’s not offensive, happy to remove or use something better?
If these lines were hand scribed in plexiglass, they would produce a hologram of a line, which would rotate as the angle of the plexiglass wrt the light is changed.
As for my experiment, it did not work. The reason is that the effect depends on the groove in the surface. Removing the surface coating does not produce the same sharp highlights as a physical groove in plexiglass. It is possible it would work if an IR or fiber laser was used so the metal is physically scribed as part of the engraved, but even then, I’m not sure the shape of groove would be right to catch the light.
I would love for lasers to work, and if anyone on this forum has an IR laser, I’d love to see whether my pattern engraved in the metal would produce a line hologram effect. The pattern is about 35mm across.
Curious how wavelength/frequency, focus, energy and other stuff can be tuned to laser etch super fine lines of desired depth? Real holograms use lasers right?
Minor update from me… inching closer to first engraving, implemented SVG Export, barely working. Fortunately, EstlCam is able to load many many arcs… EstlCam is able to generate G02/G03 arc based movements thanks to SVG being generated with arcs (PITA to code). So hopefully gcode size and engraving quality won’t suck, will see…
Long:
Simulation is better than reality. Can see the effect, but it’s too subtle for my liking. Was hoping for holographically enhanced Logo etching. Instead, have ended up with logos that look like they should be shaved, or waxed even…
Clear, 50% opaque, opaque sample :
Glossy black opaque acrylic came out best so far. Haven’t tried metal. Tried various lighting and lasers to maximize effect. Very light scratches are better than deeper gouges.
Lighting and camera need to be carefully aligned to have reflections off the arc be visible.
Extended original app to be able to load binary/text .STL files, and export SVGs with the front faces merged into an easy to select profile, so toolpath creation is easier.
Trying some other materials, with shallower engraving. Will end up with a .STL to .SVG converter if nothing else. Can export with or without arc scratches, so, can use for other scenarios beyond specular holograms…
Anyone manage to get specular hologram results they’re happy with?
Let me know if you’d like to try the modified app. If anyone’s interested I’ll spend more time cleaning up so it’s more stable/performant.
Is there any way to dial down the downforce of the diamond drag? So the scratches need to be just shallow enough to not really see but high enough to catch a hint of light. Sounds difficult.
), and/or discover interesting related work out there. Cheers!
