3d or not to 3d

[Dean Fowell]

Well i was excited to get a test file and run on my laser and see what 3D i could do well nothing it was not 3D am i doing something wrong the test pic came from gantry co does anyone have any tips

[Chuck Stone]

do you have any more information you can share? Perhaps post the file or your
settings? What software did you use? Do you have a pic of the results?


I've tried some files I found online and they work well enough, but you do
need to tweak your own settings according to the material you use. These
are on Corian.


182386182384182387182385

[Dean Fowell]

Hay Nice work Chuck,

here is the result and the test file I use 400 speed and 60 for power this is my first attempt maybe im not getting something
182390182389

[Hannu Rinne]

Dean,

I think it's a driver issue - check the needed specs from Gantry's site ( under FAQs )

Regards,
Hannu

[Chuck Stone]

Just tried a quick test with this file, seems to work in 3D OK..

Might need to share a little more about your settings in the driver. DO you have
a setup for 3D? I know in mine I can specify certain powers/speeds to individual
colors. So I set up a grayscale palette and assigned settings to several levels of gray.
This is a jpeg file, RGB and printed out of Photoshop. (all raster)
182403

[Larry Bratton]

I agree with Hannu. All machines may not be able to handle 3d without a lot of work. My Epilog driver has a setting for 3d.

[Dean Fowell]

Well I just figured it out I do not have a 3D driver for my machine I will check thanks,

All,

[Chuck Stone]

i don't have a driver for 3D either, I simply set up different
power levels for different shades of gray. For instance, white
is power level 0, black is 100 power. A mid-range gray might
be 50 power, a 75% gray might be 75 power.
It won't be that easy, and will vary by material. But it gives
you an idea. I think I use 16 shades of gray at 16 different
power levels.
If you can change and save color palettes you can set one up
for yourself to try it out. There is a 3D setting in my printer driver,
but I have no idea what (if anything) it does differently. I don't use it.

[Dean Fowell]

Thanks Chuck I just have to try agian

[Frank Corker]

Dean, you need to run the same file several times over without removing it or you will not see the benefit. The big lasers can do it in fewer passes but they still take a fair amount of runs to get a decent finish.

[Dean Fowell]

Thanks Frank I will try untill i get it,

[Chuck Stone]

Dean, you need to run the same file several times over without removing it or you will not see the benefit. The big lasers can do it in fewer passes but they still take a fair amount of runs to get a decent finish.

Hmmm... I wonder if that's why I get that pattern in the background.
I ran it in one pass. (but it's Corian, the cleanup pass doesn't do a thing)

[George Beck]

I have been experimenting with 3d and the gantry graphics work well. I have found that multiple passes to final depth works best. These were run on a 60W at 100% Power and 75% speed, 2 passes. I have recently been using 80P and 80 speed with 2 or 3 passes depending on detail of the graphic. I can do it in one pass but you get more "char" to clean up. Fast Orange Hand Cleaner and a toothbrush cleans them nicely. I have also found that it is best to try to use wood with fairly consistent grain pattern (un-interesting) but when burning this deep (3/64-1/16) knots and darker grain can mess you up.

George





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[Richard Rumancik]

i don't have a driver for 3D either, I simply set up different
power levels for different shades of gray. For instance, white is power level 0, black is 100 power. A mid-range gray might be 50 power, a 75% gray might be 75 power. . . . I think I use 16 shades of gray at 16 different power levels. . . .

Chuck, just to clarify, if you do it this way, then it will do each level of gray one-by-one, correct? At least that's how I am visualizing it happening. If I tried that trick on my LaserPro I'm pretty sure it would do the 40% gray, then the 50% gray, then the 60% gray etc etc. So that would be an interesting workaround but obviously take longer as it is only doing one color at a time. The true 3D driver changes power level on-the-fly so one pass will give a complete picture; then you have to do more passes to get depth.

Dean, I think your driver is just trying to map the image as a 1-bit i.e trying to convert it to b/w. So anything that is black (or almost black), is plotting as black, and everything else is ignored. With this setup, making more passes won't help.

You might have some success converting the g/s image to b/w in Corel PhotoPaint, using the "convert to b/w" command and then chosing Stuki or similar option. It will take some experimentation. It probably will not replicate true 3D but might give you some of the 3D effect.

But in the end to need to figure out if you will actually be able to market this as a product. It is often a "gee whiz" feature when selling lasers but many of us have found that it is not practicable timewise since customers are often not willing to pay for the necessary laser time. The result can look very interesting, but they will buy the 2D engraving instead. So manybe putting effort into perfecting that might be more beneficial.

[Chuck Stone]

Chuck, just to clarify, if you do it this way, then it will do each level of gray one-by-one, correct? At least that's how I am visualizing it happening. If I tried that trick on my LaserPro I'm pretty sure it would do the 40% gray, then the 50% gray, then the 60% gray etc etc. So that would be an interesting workaround but obviously take longer as it is only doing one color at a time. The true 3D driver changes power level on-the-fly so one pass will give a complete picture; then you have to do more passes to get depth.

Well .. I'm not sure now. It does it all on the fly here .. changing power/speed according to the color. Single pass
(unless I'm doing a hard material and choose to do a second pass)
But .. I'm working at various powers and ran these files around 5-10 speed..
Just like an inkjet wouldn't do a second pass to get more color .. it lays down more dots.
This just fires the laser at a different setting.

It does this whether I use the 3D setting or not, which is why I don't know what that
3D setting does. The laser time is no different than standard engraving at the same
settings.

[Dean Fowell]

Richard I tootally agree I am just going to get photos right , because everyone seems to want them

[Richard Rumancik]

. . It does it all on the fly here .. changing power/speed according to the color. Single pass.

Hmmm - I'm surprised at this - what system are you using? I didn't think that any of the mainstream lasers (ULS, Epilog, Trotec etc) would process the image such that it could map multiple raster colors in one horizontal pass. I need to experiment. Can anybody else comment?

Suppose you had black text on the same line as red text, each with different power settings (black text deeper than red text). You are saying your laser would raster the "black" and "red" on the same pass. I suppose this would be possible to program in a driver, as long as you were only changing power level between colors (not speed).


It does this whether I use the 3D setting or not, which is why I don't know what that 3D setting does. The laser time is no different than standard engraving at the same settings.

I haven't done it for a while - from what I remember with 3D, I send it the grayscale and enter only the power/speed setting for black. Then it changes the power level delivered to a pixel on-the-fly in relation to the gray-scale value of the pixel in the image. (Because of this, it is slower.) So I think it could generate a more continuous change of elevation than mapping to 16 colors. I think by mapping, you are generating 16 elevations. Perhaps this is adequate for most situations, but theoretically there will be a vertical step between changes in gray levels. Whereas the 3D method should not gererate visible steps as the gray can change continuously. At least that's how I see it . . .

[Mike Null]

My Trotec can do that and I think Epilog and ULS can as well.

[Dan Hintz]

I've never tried multiple colors in a single pass on my ULS, only as a separation. When I want to change power on the fly I use the 3D mode.

[Mike Lassiter]

What Richard said above is sort of my understanding too. I have purchased a couple of the Gantry files and merely send them to the laser by setting the power for only black. I recall in the manual on our laser somewhere stated something like: setting the power and speed for "black" will give that setting for pure black, and as the shade is lightened in the image the driver will adjust the power down proportionally. If color mapping has black set at 50% power, then pure black will get 50% power, if the color becomes 50% black (gray scale) then the driver will reduce the power to 50% of the setting for pure black (or 50% of 50% power). This is how you get the varying degree of depth doing 3D engraving.

Also I found by increasing the speed and running the file 3-4 times I was able to burn off some of the residue each time and very little cleaning was needed. The total time difference to laser slowly 2 times versus 3-4 times at a faster speed showed that running the speed faster more times resulted in less overall laser time; and a cleaner product after wards. I have a traveling exhaust on my carriage because we have the pass - thru module option for our laser. The exhaust is pulling smoke from about 2" from the laser beam point of contact with the material and the smoke will leave a thick residue regardless of which direction I engrave toward. While I can engrave deeper each pass going slower, I produced a good looking product faster by going faster more times across the material.

[Chuck Stone]

Hmmm - I'm surprised at this - what system are you using? I didn't think that any of the mainstream lasers (ULS, Epilog, Trotec etc) would process the image such that it could map multiple raster colors in one horizontal pass. I need to experiment. Can anybody else comment?

I've got a LaserPro Mercury. If I send a gray step wedge in RGB mode, I'll get a staircase in one pass.



Suppose you had black text on the same line as red text, each with different power settings (black text deeper than red text). You are saying your laser would raster the "black" and "red" on the same pass. I suppose this would be possible to program in a driver, as long as you were only changing power level between colors (not speed).

That's exactly what it would do. I have never changed the speed settings while
doing that, but I do have varying power settings. You can change the colors
in the printer driver, so I set up 16 levels of gray. I didn't do it with red, but
since I'm working in RGB I see no reason why it would not work that way.

Perhaps the laser isn't supposed to be working that way? I don't know. But
I've always wondered why people were so adamant about sending 1 bit
bitmaps or black & white only images.. I come from an RGB background, so
that's the way I think. Perhaps ignorance is bliss?

[QUOTE=Richard Rumancik;1638399
I haven't done it for a while - from what I remember with 3D, I send it the grayscale and enter only the power/speed setting for black. Then it changes the power level delivered to a pixel on-the-fly in relation to the gray-scale value of the pixel in the image. (Because of this, it is slower.) So I think it could generate a more continuous change of elevation than mapping to 16 colors. I think by mapping, you are generating 16 elevations. Perhaps this is adequate for most situations, but theoretically there will be a vertical step between changes in gray levels. Whereas the 3D method should not gererate visible steps as the gray can change continuously. At least that's how I see it . . .[/QUOTE]

You could be right, I don't know (and the documentation sucks) but the way
I think of it is that the driver lets me set 16 different colors. If I'm setting them
up as gray levels, the laser is estimating the correct power based on the settings
I provide. It may use 256 levels of gray for all I know, but I can only specify 16.
Perhaps it is enough for me to establish the center of 16 density ranges and the
laser takes over from there, interpreting a % above or below my own settings
in each range, according to the file data?

Dunno. But it works. I send RGB files .. Jpegs, TIF's, PSD's.. I'll send desaturated
images (so they look like grayscale) just so I can get a better idea how they'll look.

[Dan Hintz]

But I've always wondered why people were so adamant about sending 1 bit bitmaps or black & white only images.. I come from an RGB background, so that's the way I think. Perhaps ignorance is bliss?
You use 1-bit, dithered images when the substrate does not provide varying shades with varying power levels. Take a piece of black plastic with a white cap, for example... varying the power level won't get you the varying shades of gray to make a proper image, but a 1-bit dithered image with enough power to blast through the white cap is usable.