3D engraving question

[David Fairfield]

Can anyone explain what the Epilog driver does with my power and speed settings when I'm rastering in 3d mode? I realize that it inteprets shades of dark to light to apply different power levels.

But here's where I'm confused-- in 3d mode, areas where I have full black get much less power, when compared to black areas in non 3d, same speed and power settings.

I'm trying to improve my 3d results, I think it will help to know more about what the software and hardware are actually doing.

Thanks!
Dave

[Devon Jones]

this is what my handbook for my epilog says...... it should help a little



Earlier in the manual we discussed dot patterns and how those patterns are used to create raster images. 3D mode looks at the dots and the dot patterns in a very different way than Basic raster engraving mode, especially where it concerns either color, or grayscale images.
In 3D mode, instead of looking at the dots and determining where to fire the laser based on the dot spacing, we look at the dots and determine how much laser power (wattage) to apply to each dot, and that’s the big difference between Basic raster engraving mode and 3D. In Basic raster engraving mode, every dot is fired at the same laser output (wattage). In 3D mode we have the ability to adjust the laser output for every dot.
An additional aspect of 3D mode is that, unlike Basic mode, the laser fires
continuously between most dots – even if it is engraving from a 10% fill pattern to a 30% fill pattern. This is by design so there is a gradual change in the depth of engraving when the artwork transitions from one shade of gray to another. The only time that this is not true is when the artwork changes from 100% black to 100% white (or visa versa). Because we adjust the way the laser fires in 3D mode we also have to adjust the artwork that is used to create good 3D images, and this is where 3D engraving gets difficult. In 3D mode, since we’re going to vary the laser power output for every dot, we want artwork that will produce more than one level of gray. We want artwork that gradually blends from one shade of gray to another. Engraving either of the two gray boxes on the previous page will not produce a 3D affect because each

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box is only a single shade of gray. You need an object that looks something like the circle below to create a 3D image.
This explanation describes the most basic functions of 3D engraving and some of the theory behind it. What it doesn’t describe is the difficulty that most users will have in creating acceptable 3D artwork. Creating a 3D image that will look good after engraving can be very difficult to achieve because most software packages do not provide the necessary tools to take complex objects and blend them in more than one direction from dark to light (or, visa versa). There are some 3D graphics software packages available that will create 3D images, but they generally cost between $3,500 and $10,000 USD. Ask your Epilog representative
if you would like more information on these software packages.
Engraving this circle in 3D mode will create a dome with center being
the high point (because it’s a light shade of gray) and the outside edge
being deep (because it’s a darker shade of gray).

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3D engraving usually requires more than one pass to get the depth of engraving necessary to produce the dimensional relief that makes 3D engraving look good. Many users will engrave an image using two or three passes to get the depth they are looking for. As long as you do not move the piece that is being engraved, the multiple passes will align perfectly with the first pass. The following images
show examples of a simple piece of 3D artwork.
These images are available in Corel 11 format as Leaf1.cdr and Leaf2.cdr, and as bitmaps (Leaf1.bmp and Leaf2.bmp) on the Drivers and Documentation disk that came in the accessories disk with your machine.

[David Fairfield]

Thanks Devon. That's the operator instructions but it still doesn't really explain how the laser driver is manipulating the power levels when in 3d mode.

I did some experiments and I think what happens is the Epilog driver processes various shades of black to white in the artwork as percentages and applies power accordingly. So black is 100% power and white is 0% and greys are levels in between. This is regardless of whatever power settings you dial in. So basically the artwork is setting the power levels for you.

Dave

[Frank Corker]

Yes Dave, that's what it is doing. A good greyscale image will give you a good 3d effect.

[Steve Clarkson]

"the Epilog driver processes various shades of black to white in the artwork as percentages and applies power accordingly. So black is 100% power and white is 0% and greys are levels in between."



But doesn't it do that in regular mode (ie. Clipart, Stucki, etc.)....how else would you get shades of grey on a piece of wood, for example? Spacing of the dots?

[David Fairfield]

Ya know I've been wondering the same thing. I can't really figure how 3d mode is different from regular or photo mode, except it doesn't give you any control over the power settings. Its just at 100% all the time.

Any ideas what the 3d mode is doing differently, if anything?

Dave

[Niklas Bjornestal]

"the Epilog driver processes various shades of black to white in the artwork as percentages and applies power accordingly. So black is 100% power and white is 0% and greys are levels in between."



But doesn't it do that in regular mode (ie. Clipart, Stucki, etc.)....how else would you get shades of grey on a piece of wood, for example? Spacing of the dots?

In regular mode it just adjust the spacing of dots.

[David Fairfield]

3d mode is different from regular mode, as the dot pattern isn't there.

So it seems to me 3d mode is just photo mode with power locked at 100%. The only difference I'm seeing in my results using a grey scale I drew in AI is a slight blur to edges in 3d mode that isn't there in Photo mode. Maybe there is some difference in dithering but Photo mode is actually giving me better 3d results.

Maybe I'm still missing something. I'd really like to know specifically what the driver is doing in 3d mode.

Comments, anyone?

Dave

[onur cakir]

Once i experimented 3D with "fountain fill" tool in corel x3 (under fill dialog)

I drove a square and filled it with fountain fill from white to black.

So it went deeper on wood on black areas. But i didnt have time to experiment on an image.